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Phase 1b study of berzosertib and cisplatin in patients with advanced triple-negative breast cancer

Phase 1b study of berzosertib and cisplatin in patients with advanced triple-negative breast cancer www.nature.com/npjbcancer ARTICLE OPEN Phase 1b study of berzosertib and cisplatin in patients with advanced triple-negative breast cancer 1 2 2 3 3 4,5 Melinda L. Telli , Sara M. Tolaney , Geoffrey I. Shapiro , Mark Middleton , Simon R. Lord , Hendrik Tobias Arkenau , 6,7 8 9,16 10 11 12 Andrew Tutt , Vandana Abramson , Emma Dean ,Tufia C. Haddad , Robert Wesolowski , Jordi Ferrer-Playan , 13 13 14 14 12,17 Thomas Goddemeier , Thomas Grombacher , Jennifer Dong , Patricia Fleuranceau-Morel , Ivan Diaz-Padilla and Ruth Plummer Platinum derivatives are commonly used for the treatment of patients with metastatic triple-negative breast cancer (TNBC). However, resistance often develops, leading to treatment failure. This expansion cohort (part C2) of the previously reported phase 1b trial (NCT02157792) is based on the recommended phase 2 dose of the combination of the ataxia-telangiectasia and Rad3- related (ATR) inhibitor berzosertib and cisplatin observed in patients with advanced solid tumors, including TNBC. Forty-seven 2 2 patients aged ≥18 years with advanced TNBC received cisplatin (75 mg/m ; day 1) and berzosertib (140 mg/m ; days 2 and 9), in 21- day cycles. Berzosertib was well tolerated, with a similar toxicity profile to that reported previously for this combination. The overall response rate (90% confidence interval) was 23.4% (13.7, 35.8). No relevant associations were observed between response and gene alterations. Further studies combining ATR inhibitors with platinum compounds may be warranted in highly selected patient populations. npj Breast Cancer (2022) 8:45 ; https://doi.org/10.1038/s41523-022-00406-0 INTRODUCTION germline or somatic BRCA1/2 mutations. Despite some progress being made, there remains a significant unmet medical need to Triple-negative breast cancer (TNBC) accounts for ~10–20% of all improve treatment outcomes for patients with advanced TNBC. patients with breast cancer and is traditionally defined by the lack Ataxia telangiectasia and Rad3-related (ATR) and ataxia- of expression of the estrogen and progesterone receptors, telangiectasia-mutated (ATM) protein kinases are members of alongside no overexpression or amplification of the human 1 the DNA damage response (DDR) family of proteins. Both ATM and epidermal growth factor receptor 2 (HER2) . TNBC has the poorest 2 ATR are key regulators of cell cycle checkpoint control and prognosis amongst all breast cancer subtypes ; the reported predominantly direct repair of DNA via homologous recombina- 5-year survival for patients with any metastatic breast cancer is tion . Loss or inactivation of a single member of the DDR family 3,4 ~27%, compared with 11% in patients with metastatic TNBC .At of proteins has been associated with a greater reliance on other least four different subtypes of breast cancers have been family members to respond to DNA damage, including damage identified according to their gene expression profile, namely: induced by platinum-based chemotherapy. Preclinical experi- 5,6 luminal A, luminal B, HER2-enriched, and basal-like (basal) . ments conducted using human ovarian and breast cancer cell In the setting of advanced TNBC, carboplatin has previously lines suggest that their sensitivity to DNA-damaging agents may demonstrated similar efficacy and a more favorable toxicity profile be increased when used in combination with ATR inhibitors . 7–9 compared to docetaxel , and therefore platinum derivates have Preclinical evidence also suggests that tumor protein 53 (TP53) commonly been used for the treatment of metastatic disease . mutant status correlates with the response to ATR inhibition in However, the treatment options for patients with advanced TNBC 18–20 combination with DNA damaging agents . Since basal breast have expanded in the last few years as new therapeutic cancers often present with a high frequency of TP53 muta- 21,22 modalities, such as immune checkpoint inhibitors and tions , combining ATR inhibitors and DNA-damaging che- 11–13 antibody–drug conjugates, have become available . Poly motherapy is a theoretically efficacious therapeutic approach in (ADP-Ribose) Polymerase (PARP) inhibitors have also been this setting. approved for use in patients with germline Breast Cancer Gene Berzosertib (formerly M6620, VX-970) is an intravenously (i.v.) (BRCA) 1/2-mutated, HER2-negative metastatic breast cancer. This administered, highly potent and selective, first-in-class inhibitor of includes patients with TNBC who have germline BRCA1/2 ATR . Preclinical studies have demonstrated the ability of ATR mutations, with clinical benefits also extending to those with inhibitors to sensitize breast cancer cell lines to platinum-based somatic BRCA1/2 mutations, although it is unclear whether similar chemotherapy, namely cisplatin . The part A and B cohorts of the 14,15 benefits will be observed in patients with TNBC without first-in-human study (NCT02157792) phase 1 trial of berzosertib 1 2 3 4 Stanford University School of Medicine, Stanford, CA, USA. Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA. University of Oxford, Oxford, UK. Sarah 5 6 Cannon Research Institute, HCA Healthcare, London, UK. University College London, London, UK. Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer 7 8 Research and Kings College, London, UK. Guy’s and St Thomas’ NHS Foundation Trust, London, UK. Vanderbilt University Medical Center, Vanderbilt-Ingram Cancer 9 10 11 Center, Nashville, TN, USA. The University of Manchester and The Christie NHS Foundation Trust, Manchester, UK. Mayo Clinic, Rochester, MN, USA. The Ohio State University 12 13 Comprehensive Cancer Center, Columbus, OH, USA. Ares Trading SA, Eysins, Switzerland, an affiliate of Merck KGaA, Darmstadt, Germany. the healthcare business of Merck 14 15 KGaA, Darmstadt, Germany. EMD Serono, Billerica, MA, USA. Newcastle University and Northern Centre for Cancer Care, Newcastle Hospitals NHS Foundation Trust, Newcastle 16 17 upon Tyne, UK. Present address: Oncology R&D, AstraZeneca, Cambridge and Alderley Park, Macclesfield, UK. Present address: GlaxoSmithKline, Zug, Switzerland. email: Ruth.Plummer@newcastle.ac.uk Published in partnership with the Breast Cancer Research Foundation 1234567890():,; M.L. Telli et al. established the recommended phase 2 dose (RP2D) and demon- Table 1. Patient demographics and baseline characteristics. strated its tolerability, both as a single agent and in combination with certain chemotherapies; preliminary signs of efficacy were Characteristic, N (%) unless stated Total N = 47 also observed in patients with a range of solid tumor types, 24,25 including TNBC . The tolerability, preliminary signs of efficacy, Sex and favorable pharmacokinetics (PK) identified in this study have Male 0 26–28 been confirmed in other clinical studies of berzosertib .A Female 47 (100) berzosertib–topotecan combination has also been evaluated in a Ethnicity recent proof-in-concept phase 2 study, reporting an objective Caucasian/White 41 (87.2) response rate of 36% (9/25) and a median duration of response of 6.4 months in patients with SCLC, including platinum-resistant Non-Caucasian/non-White 3 (6.4) patients . Parts A and B of NCT02157792 were dose escalation Age, years; median (range) 48.0 (35–73) studies that established the RP2D of berzosertib in combination Baseline ECOG PS with gemcitabine (part A; berzosertib 210 mg/m [days 2 and 9] in 0 25 (53.2) 2 24 combination with gemcitabine 1000 mg/m [days 1 and 8]) and 1 22 (46.8) cisplatin (part B; berzosertib 140 mg/m [days 2 and 9] in 2 25 combination with cisplatin 75 mg/m [day 1]) in 21-day cycles. Prior anticancer therapy Here we report the results from the C2 expansion cohort of the Chemotherapy 45 (95.7) same study, which investigated the safety and tolerability, efficacy, Immunotherapy 1 (2.1) PK, and potential predictive biomarkers of berzosertib in Other 11 (23.4) combination with cisplatin in patients with advanced TNBC whose Missing 2 (4.3) tumors were germline BRCA1/2 wild-type and basal subtype. Number of previous anticancer therapy regimens Neoadjuvant 16 (34.0) RESULTS Adjuvant 27 (57.4) Patient demographics and disposition st 1 line, metastatic disease 24 (51.1) Forty-seven patients were enrolled into this study, all of whom nd 2 line, metastatic disease 10 (21.3) were included in the safety analysis set (SAF) and modified full nd >2 line, metastatic disease 5 (10.6) analysis set (mFAS) for efficacy (Table 1). The PK analysis set (PAS) included all enrolled patients who received at least one dose of Missing 2 (4.3) berzosertib and provided at least one measurable post-dose TP53 concentration; 41 patients were included in the PAS, with 6 Wild type 2 (4.3) patients excluded as they did not have a measurable post-dose PK Mutant 34 (72.3) berzosertib concentration. The modified primary efficacy set Missing 11 (23.4) (mPES) included all patients in the mFAS who were basal subtype BRCA1/2 and BRCA1/2 germline wild-type; 35 patients were included in the mPES, with 12 patients excluded due to a lack of BRCA1/2 gWT Wild type 31 (66) status data or were not basal subtype. Among all patients, 34 Mutant 5 (10.6) (72.3%) were TP53 mutant; 2 (4.3%) were TP53 wild-type; 31 (66%) Missing 11 (23.4) were BRCA1/2 germline wild-type; and 36 (76.6%) were basal Basal subtype subtype, based on Prediction Analysis of Microarray 50 (PAM50). In Yes 36 (76.6) the 7 patients who were not basal subtype, 4 (57.1%) had a TP53 mutation, 1 (14.3%) was TP53 wild-type and 2 (28.6%) had an No 7 (14.9) unknown TP53 mutational status; in the 36 (76.6%) patients who Missing 4 (8.5) were basal subtype, 29 (81%) had a TP53 mutation, 1 (3%) was ATM ataxia-telangiectasia mutated, BRCA1/2 breast cancer gene 1/2, ECOG TP53 wild-type, and 6 (17%) had an unknown TP53 mutational PS Eastern Cooperative Oncology Group Performance Status, TP53 tumor status. Four patients had an unknown subtype (Table 2). protein 53. In all, 24 (51.1%) patients had previously received only one line Only patients with biomarker status determined by FoundationOne® CDx of therapy for metastatic disease, 10 (21.3%) patients had received next generation sequencing were reported. two lines of therapy, and 5 (10.6%) received more than two lines Patients with unknown BRCA1/2 status were prospectively tested at of therapy for metastatic disease. screening by BRCAnalysis assay (Myriad Genetics); patients that were found All 47 patients in the mFAS received at least one dose of to be BRCA1/2 germline mutant were still enrolled in the study. Assessment for basal subtype was performed retrospectively via PAM50 berzosertib, 46 (97.9%) received at least one dose of cisplatin, and analysis (Prosigna). 12 (25.5%) received at least one dose of carboplatin; the patient who received berzosertib without cisplatin received at least one dose of carboplatin. Thirty-eight (80.9%) patients completed treatment with berzosertib, while nine (19.1%) discontinued treatment, primarily due to patient decision (four, 8.5%) or adverse events (AEs; two, 4.3%). Sixteen patients (34%) discon- Table 2. TP53 mutational status. tinued cisplatin, primarily due to AEs (12.8%) and remained on TP53 status Basal subtype (N = 36) Non-basal subtype (N = 7) berzosertib monotherapy until PD. The median (range) duration of treatment for berzosertib in combination with cisplatin was 15.0 (5 Wild type 1 (3.0) 1 (14.3) cycles) (2.0, 137.1) weeks. No patients died during this study. Mutant 29 (81.0) 4 (57.1) Missing 6 (17.0) 2 (28.6) Efficacy TP53 tumor protein 53. Forty-seven patients were included in the mFAS; however four patients were non-evaluable. The objective response rate (ORR npj Breast Cancer (2022) 45 Published in partnership with the Breast Cancer Research Foundation 1234567890():,; M.L. Telli et al. [90% confidence interval (CI)]) was 11/47 (23.4%) patients (13.7, of CR were previously treated only in the neoadjuvant/adjuvant 35.8), the best overall response (BOR) was complete response (CR) setting, while no patients who had received more than two lines for two (4.3%) patients, partial response (PR) for nine (19.1%) of therapy for metastatic disease achieved a response. The median duration of response (DOR; [90% CI]) was patients, and stable disease (SD) for 18 (38.3%) patients (Table 3 6.0 months (5.1, not defined). Median progression-free survival and Fig. 1a); all responses were confirmed. For patients with SD (PFS; [90% CI]) was 4.0 months (2.8, 6.0), and median overall (N = 18), 3 patients (16.7%) progressed within 3 months, 10 survival (OS; [90% CI]) was 12.4 months (7.8, 14.5). (55.6%) patients progressed within 3–6 months, and 5 (27.8%) Similar results were observed for the mPES: the ORR (90% CI) patients progressed within 6–12 months. BOR was also retro- was 9/35 (25.7%) patients (14.1, 40.6), 2 (5.7%) patients had a BOR spectively stratified by prior lines of treatment for metastatic of CR, 7 (20.0%) had a BOR of PR, and 15 (42.9%) had a BOR of SD; disease (Supplementary Table 1); all patients who achieved a BOR 10 (28.6%) patients had a BOR of PD. The ORR for patients who were germline BRCA1/2 wild-type vs mutant were 7/31 (22.6%) Table 3. Efficacy responses (modified full analysis set, N = 47). patients vs 2/5 (40.0%) patients, respectively, while for patients who were basal subtype vs those who were not, the ORRs were Efficacy outcome Patients, n (%) unless stated 9/36 (25.0%) patients vs 1/7 (14.3%) patients, respectively. However, no formal statistical comparison for these subgroups BOR was made. Further information on ORR by biomarker status can be CR 2 (4.3) found in Table 4. PR 9 (19.1) SD 18 (38.3) Safety and tolerability PD 14 (29.8) A summary of treatment-emergent AEs (TEAEs) is presented in Not evaluable 4 (8.5) Table 5. The most common TEAEs, which occurred in more than ORR, N (%), (90% CI) 11 (23.4) (13.7, 35.8) 50% of patients, were nausea (N = 39, 83.0%), fatigue (N = 32, DCR, N (%), (90% CI) 29 (61.7) (48.7, 73.6) 68.1%), neutropenia (N = 29, 61.7%), and vomiting (N = 28, 59.6%); a full list of TEAEs affecting ≥20% of patients can be found in Median PFS (months), (90% CI) 4.0 (2.8, 6.0) Table 5. TEAEs of grade ≥3 occurred in 32 patients (62.1%). TEAEs Median OS (months), (90% CI) 12.4 (7.8, 14.5) of grade ≥3 occurring in more than 10% of patients were Median DOR (months), (90% CI) 6.0 (5.1, nd) neutropenia (N = 18, 38.3%), anemia (N = 12, 25.5%), thrombocy- DCR was defined as the proportion of patients with disease control, topenia (N = 6, 12.8%), and vomiting (N = 6, 12.8%). Febrile defined as a BOR of CR, PR, or SD. neutropenia occurred in two (4.3%) patients. Forty-five (95.7%) BOR best overall response, CI confidence interval, CR complete response, patients had a berzosertib-related TEAE; of these, 27 (57.4%) had a DCR disease control rate, DOR duration of response, nd not defined, ORR related TEAE of grade ≥3. There were no notable adverse events overall response rate, OS overall survival, PD progressive disease, PFS relating to laboratory results, vital signs or electrocardiogram progression-free survival, PR partial response, SD stable disease. (ECG) measurements. a b 20 CR PD PR –20 SD NE –40 –60 –80 –100 ** TMB High level TMB Intermediate level TMB Low level TMB LOH High level LOH LOH Intermediate level LOH Low level Data unavailable TP53 p53-pathway BRCA1 Mutant Wild type BRCA2 Data unavailable ATM ARID1A CR PR SD PD TMB intermediate level TMB low level LOH high level LOH low level Unknown Data unavailable 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Treatment duration (months) Fig. 1 Best percentage change in tumor size from baseline and tumor response by LOH and TMB scores (modified full analysis set). a Best percentage change in tumor size from baseline, b tumor response by LOH and TMB scores. Patients without on-treatment target lesion measurements are not shown in Fig. 1a. Patients without response assessments are not shown in Fig. 1b. All response categories were determined according to RECIST 1.1 criteria. Full details of mutations can be found in Supplementary Table 5. CR complete response, LOH loss of heterozygosity, PD progressive disease, PR partial response, RECIST Response Evaluation Criteria in Solid Tumors, SD stable disease, TMB tumor mutational burden. Published in partnership with the Breast Cancer Research Foundation npj Breast Cancer (2022) 45 Maximum percentage change in tumor size from baseline Patients M.L. Telli et al. confirmed response, compared with only 1 of the 5 patients with Table 4. ORR for selected biomarker subgroups; modified full analysis an intermediate TMB score. set (N = 47). A 40-year-old female patient with grade 3, metastatic, BRCA1/2 negative TNBC achieved a CR with a duration of 28.6 months, Gene Patients, n Responses, n ORR, % (90% CI) remaining in CR at the end of the study. The patient achieved a TP53 BOR of CR despite disease progression on previous chemother- apeutic treatment in the (neo)adjuvant setting. Further assess- Wild type 2 0 0.0 (0.0, 77.6) ment of the biomarker status of this patient revealed Mutant 34 9 26.5 (14.6, 41.6) heterozygous germline mutations in genes including adenovirus ARID1A E1A-associated cellular p300 transcriptional co-activator protein Wild type 34 9 26.5 (14.6, 41.6) (EP300), DNA polymerase delta 1, catalytic subunit (POLD1), and Mutant 2 0 0.0 (0.0, 77.6) Tumor Growth Factor Beta Receptor 2 (TGFBR2), all variants of unknown significance. Archival tumor demonstrated low LOH and ATM TMB scores, somatic TP53 mutation and several gene amplification Wild type 31 8 25.8 (13.5, 41.8) events relating to MYC (copy number 18), CCNE1 (Cyclin E1; copy Mutant 5 1 20.0 (1.0, 65.7) number 14), and RAD21 (copy number 18). Germline BRCA1/2 Wild type 31 7 22.6 (11.1, 38.3) Pharmacokinetics Mutant 5 2 40.0 (7.6, 81.1) The PAS included 41 patients, with six patients excluded because Basal subtype their post-dose berzosertib concentration was outside the limit of Yes 36 9 25.0 (13.7, 39.6) quantification. The administered i.v. berzosertib dose of 140 mg/ m was within the dose range that has previously shown dose- ARID1A AT-rich interaction domain 1A, ATM ataxia-telangiectasia-mutated, dependent berzosertib PK as monotherapy or in combination with BRCA1/2 breast cancer gene 1/2, CI confidence interval, ORR overall 24–26 either carboplatin or cisplatin . The observed berzosertib response rate, PAM50 Prediction Analysis of Microarray 50, TP53 tumor concentration data in this expansion cohort were generally protein 53. Only patients with biomarker status determined by FoundationOne® CDx consistent with those reported previously at the same dose next-generation sequencing were reported. level . Cisplatin had no apparent effect on berzosertib PK Basal subtype was determined via PAM50 analysis (Prosigna) and was (Supplementary Fig. 1). Key berzosertib PK parameters from this performed retrospectively. study, presented as geometric mean (geometric coefficient of variance), were as follows: maximum observed concentration (C [ng/mL]) – 555 (42.9%); area under the curve (AUC) from max In all, 15 (31.9%) patients had a serious TEAE, with 13 (27.7%) start of infusion to the 4-h sampling time after start of infusion having a grade ≥3 serious TEAE. Of these patients, 10 (21.3%) (AUC [ng.h/mL]) – 1110 (26.4%). The C in this expansion 0–4 max reported a serious TEAE related to berzosertib, 8 (17%) related to cohort was slightly lower than the 652 ng/mL (25%) and 854 ng/ cisplatin, and 2 (4.3%) related to carboplatin. mL (63%) observed in the lead-in period and in the berzosertib In total, 11 (23.4%) patients experienced a TEAE leading to a and cisplatin combination cohort, respectively, at the same dose dose reduction in at least one study drug (3 [6.4%], 8 [17.0%], and level in part B. The partial AUC was ~23% of the reported 0–4 1 [2.1%] TEAEs leading to permanent dose reduction were related AUC in part B . 0–∞ to berzosertib, cisplatin, and carboplatin, respectively). In total, 24 (51.1%) patients experienced a TEAE leading to temporary discontinuation of at least one study drug (21 [44.7%], DISCUSSION 15 [31.9%], and 5 [10.6%] TEAEs leading to temporary disconti- In this dose expansion cohort study, berzosertib 140 mg/m (days nuation were related to berzosertib, cisplatin, and carboplatin, 2 and 9) administered alongside cisplatin 75 mg/m (day 1) in 21- respectively). Five (10.6%) patients in this expansion cohort day cycles was well tolerated in patients with advanced TNBC. The permanently discontinued berzosertib during the study due to safety profile of this combination was broadly consistent with that TEAEs, three of whom discontinued due to berzosertib-related of the individual agents and no new or unexpected safety signals TEAEs (one patient each experienced neutropenia [grade 2], were identified for berzosertib . Although a high rate of anemia and thrombocytopenia [both grade 3], and peripheral treatment interruptions was observed with berzosertib, these neuropathy [grade 2]). did not translate into dose reductions or permanent treatment discontinuation. The rate of bone marrow toxicity observed in this Biomarkers study with a limited number of participants may indicate the No conclusive association was identified between clinical outcome potential of ATR inhibition to increase the hematologic toxicity of (ORR or PFS) and the mutational status of TP53, AT-rich interaction cisplatin and may be an on-target effect. However, these toxicities domain 1A (ARID1A), ATM or BRCA1/2 (Table 4 and Supplementary were generally manageable and did not result in significant dose Table 2). Post-hoc exploratory biomarker assessments of loss of reductions or treatment discontinuations. heterozygosity (LOH) status and tumor mutational burden (TMB) The observed PK data were generally consistent with the PK 30,31 28 using Foundation Medicine’s (FMI) FoundationOne® CDx assay data reported previously at the same dose levels . A population in these patients did not identify any statistically significant PK model built based on pooled data from two phase 1 studies, association between LOH and response or TMB and response (Fig. including this expansion cohort, suggested that administration of 1b). However, 7 of the 11 patients with a confirmed response had cisplatin does not affect observed berzosertib PK parameters . a high LOH score and 7 of the 16 total patients with a high LOH Although the effects of TNBC tumor type on clearance were score responded to treatment, compared with only 1 of the 12 estimated in the model, an association between tumor type and patients with a low LOH score. Although the association was not PK is not anticipated . statistically significant (p = 0.09), the results suggest an enrich- With the implicit caveats associated with cross-trial compar- ment of responders in tumors with high LOH (OR = 7.96) isons, the response rate observed in this expansion cohort (ORR: (Supplementary Table 3). No patients had a tumor with a high 23.4%; DOR: 6.0 months) was broadly consistent with those TMB score. In all, 7 of the 27 patients with a low TMB score had a observed in historical studies conducted in patients with npj Breast Cancer (2022) 45 Published in partnership with the Breast Cancer Research Foundation M.L. Telli et al. Table 5. Overview of TEAEs for berzosertib and cisplatin (safety analysis set, N = 47). Patients, N (%) Berzosertib + Cisplatin Berzosertib + Cisplatin Any grade Grade ≥3 N = 47 N = 47 TEAE 47 (100) 36 (76.6) Berzosertib-related TEAE 45 (95.7) 27 (57.4) Cisplatin or carboplatin-related TEAE 47 (100) 31 (66.0) Berzosertib or cisplatin or carboplatin-related TEAE 47 (100) 32 (68.1) TEAEs occurring in ≥20% of patients Nausea 39 (83.0) 4 (8.5) Fatigue 32 (68.1) 1 (2.1) Neutropenia 29 (61.7) 18 (38.3) Vomiting 28 (59.6) 6 (12.8) Tinnitus 21 (44.7) 0 Anemia 19 (40.4) 12 (25.5) Headache 18 (38.3) 0 Diarrhea 16 (34.0) 0 Constipation 14 (29.8) 0 Dizziness 11 (23.4) 0 Decreased appetite 10 (21.3) 0 Serious TEAE 15 (31.9) 13 (27.7) Berzosertib-related serious TEAE 10 (21.3) 8 (17.0) Cisplatin or carboplatin-related serious TEAE 10 (21.3) 8 (17.0) Berzosertib or cisplatin or carboplatin-related serious TEAE 10 (21.3) 8 (17.0) TEAEs leading to permanent discontinuation of treatment TEAE leading to permanent discontinuation of berzosertib 5 (10.6) NR Berzosertib-related TEAE leading to permanent discontinuation of berzosertib 3 (6.4) NR Cisplatin-related TEAE leading to permanent discontinuation of cisplatin 8 (17.0) NR Carboplatin-related TEAE leading to permanent discontinuation of carboplatin 3 (6.4) NR TEAE leading to a dose reduction in at least one study drug 11 (23.4) NR Berzosertib-related TEAE leading to dose reduction in berzosertib 3 (6.4) NR Cisplatin-related TEAE leading to dose reduction in cisplatin 8 (17.0) NR Carboplatin-related TEAE leading to dose reduction in carboplatin 1 (2.1) NR TEAE leading to temporary discontinuation of at least one study drug 24 (51.1) NR Berzosertib-related TEAE leading to temporary discontinuation of berzosertib 21 (44.7) NR Cisplatin-related TEAE leading to temporary discontinuation of cisplatin 15 (31.9) NR Carboplatin-related TEAE leading to temporary discontinuation of carboplatin 5 (10.6) NR TEAE leading to death 0 0 NR not reported, TEAE treatment-emergent adverse event. advanced TNBC treated with platinum-based therapy (TNT trial, p53 pathway impairment. Several co-occurring DDR alterations 7,32 carboplatin ORR: 31.4%; TBCRC009 trial, ORR: 25.6%) . may be necessary to confer sensitivity to the combination of ATR Although preclinical evidence suggested a potent synergistic inhibition and platinum-derived chemotherapeutics. effect of berzosertib and cisplatin on cancer cell survival, One patient with TNBC and several co-occurring DDR alterations particularly in tumors with TP53 mutations, this was not observed experienced a CR lasting for 28.6 months. Further assessment of 18–20 with the berzosertib and cisplatin doses utilized in this study . the biomarker status of this patient revealed a number of The lower dose of berzosertib used in this study may have been amplification events relating to MYC, CCNE1, and RAD21. This insufficient for target engagement. For instance, a Phase 2 proof- exceptional response might be explained in part by the presence of-concept study investigating a dose of 210 mg/m of berzosertib of these specific gene amplifications. Overexpression of MYC and in combination with topotecan demonstrated durable tumor CCNE1 (Cyclin E1) have been shown to increase replication stress, 29 34,35 regression in patients with small-cell neuroendocrine cancers , thus sensitizing tumors to ATR inhibition . The role of RAD21 is whereas no benefit in PFS was shown in a Phase 2 study less clear in this context, as up-regulation of RAD21 has been investigating a dose of 90 mg/m berzosertib in combination with shown to mitigate replication stress arising from MYC over- 33 36 gemcitabine in patients with advanced urothelial carcinoma . expression . Future research may explain the complex interplay Additionally, patients in the clinical setting are likely to have between co-occurring gene amplifications and ATR inhibition. tumors with complex genetic aberrations; hence, solely assessing Taken together, no conclusive associations were observed for TP53 mutational status may not provide a robust assessment of gene alterations linked to higher susceptibility to ATR inhibition or Published in partnership with the Breast Cancer Research Foundation npj Breast Cancer (2022) 45 M.L. Telli et al. increased reliance on ATR in preclinical experiments, such as ATM unknown before screening, BRCA1/2 status was determined by central prospective germline testing during screening, and patients found to be and ARID1A alterations . This may be due to the low patient germline BRCA1/2 mutant were still enrolled. If possible, assessment of numbers; for example, there were only five patients with an ATM basal subtype was performed retrospectively. mutation (Supplementary Table 4). However, an enrichment of Prior taxane and/or an anthracycline chemotherapy in the metastatic responses would have been expected in patients with ATM loss, setting was allowed, alongside one other non-platinum-based chemother- which raises questions related to the functionality of ATM, or how apy in the first- or second-line (no restrictions were placed on prior this is defined (i.e. based on loss-of-function mutation, mono- immunotherapy or targeted treatment in the metastatic setting, unless allelic vs bi-allelic loss, or protein expression). Other studies have combined with a cytotoxic agent). pointed towards such an association between ATM protein loss Key exclusion criteria included: any prior platinum therapy in the and response to ATR inhibition . The identification of biomarkers metastatic setting (adjuvant or neoadjuvant platinum-based chemother- apy was permitted if this was completed within 6 months of screening); of response to ATR inhibitors continues to be a very active field of relapse within 3 months of completion of prior adjuvant or neoadjuvant research. chemotherapy; known BRCA1/2 germline mutations, either determined As LOH can indicate the presence of historical homologous and documented prior to screening or determined during screening; and 39,40 recombination deficiency and has also been reported to documented intrinsic subtype other than basal by PAM50. predict response to platinum-based neoadjuvant chemotherapy in Full inclusion and exclusion criteria are provided in the supplementary patients with TNBC , an exploratory biomarker analysis focused information. on evaluating genetic alterations and genomic signatures was conducted in this trial. Interestingly, there were a greater number Treatments of clinical responses in patients with a high LOH status (7/16) The patients enrolled in this cohort received the RP2D established in part within this patient population compared with patients with a low 25 2 B ; following enrollment, patients received berzosertib (140 mg/m )on LOH status (1/12). 2 days 2 and 9, ~24 h after receiving cisplatin (75 mg/m ; day 1) in 21-day In conclusion, the combination of berzosertib and cisplatin in cycles. patients with advanced, pretreated TNBC was well tolerated. A patient could receive berzosertib in combination with carboplatin if Although the observed efficacy signal does not warrant further they had not progressed but were unable to tolerate treatment due to toxicities associated with cisplatin, or it was considered by the Investigator development of the present combination and dose in patients to be in their best interest. The starting doses following switching would with TNBC in a phase 2/3 setting, the clinical evaluation of be berzosertib (90 mg/m ) plus carboplatin (AUC 5 mg/min/mL). berzosertib in a very selective sub-population of patients with Patients received treatment until PD, unacceptable toxicity, withdrawal, breast cancer might be of interest to confirm the role of certain or non-compliance with study protocol. genetic or molecular markers, such as LOH. Clinical trials evaluating berzosertib in combination with DNA damage- Objectives inducing chemotherapy, such as topotecan, are ongoing in a The primary objectives of this study were to evaluate the safety, variety of solid tumors including small-cell lung cancer. tolerability, and preliminary efficacy of berzosertib when combined with cisplatin in patients with advanced, basal, germline BRCA1/2 wild-type TNBC, with or without TP53 mutations. Exploratory objectives of this study METHODS included the evaluation of biomarkers potentially associated with response Study design to berzosertib in combination with cisplatin. This was a multicenter, open-label, non-randomized, first-in-human, phase 1 study conducted in six parts (A, B, B2, C1, C2, C3; NCT02157792, Assessments and endpoints registered 06 June 2014). Part C2 was a single-arm, dose expansion cohort evaluating the safety and preliminary efficacy of berzosertib combined The primary safety endpoints were TEAEs; clinical laboratory values with cisplatin in patients with advanced TNBC using the berzosertib RP2D (chemistry, hematology, urinalysis, coagulation); ECG; and vital signs. TEAEs identified in part B. Patients were enrolled across five sites in the UK and 12 were defined as any AEs that were reported, or worsened, on or after study in the USA, between 09 December 2015 (study initiation date) and 11 drug initiation, through the safety follow-up visit. Serious TEAEs were March 2020 (study completion date, when the final patient completed defined as any AEs that were a congenital or birth abnormality, resulted in their last visit). persistent or significant disability or incapacity, required or prolonged in- This study was conducted in accordance with the ethical principles of patient hospitalization, were life-threatening or resulted in death, or were the International Council for Harmonisation guideline for Good Clinical otherwise deemed medically important. Related TEAEs were defined as any AE reported by the Investigator to have a relationship to study Practice and the Declaration of Helsinki, as well as with applicable local treatment, or where the relationship was unknown. regulations. The Clinical Study Protocol and all required associated All AEs were coded according to the Medical Dictionary for Regulatory documents were approved by the following responsible Institutional Activities V21.0 and graded according to the National Cancer Institute Review Boards (IRB) or Independent Ethics Committees of the individual Common Terminology Criteria for Adverse Events v4.0 . study sites: The Washington University in St. Louis IRB, Vanderbilt The primary efficacy endpoint of this study was the ORR, defined as the University IRB, North East – Tyne & Wear South Research Ethics Committee, proportion of participants with a BOR of PR or CR (summarized as objective Northwestern University Biomedical IRB, Stanford University Administrative response [OR] according to RECIST 1.1), where both PR and CR were Panels on Human Subjects in Medical Research Board, Greenville Health confirmed by repeat assessments performed no less than 4 weeks after the System IRB, Mayo Clinic IRB, The University Hospitals IRB, US Oncology IRB, criteria for response was first met. NRES Committee North East – Sunderland, Dana Farber Cancer Institute Tumor assessments were performed from baseline until either end of IRB, Western IRB. All patients were required to provide written informed treatment or PD using RECIST 1.1 guidelines. Initial disease was consent prior to enrollment. documented using baseline imaging scans (computed tomography or magnetic resonance imaging) taken within 14 days prior to the first dose of Patients study drug; imaging was repeated at the end of every 2 cycles for the first Eligible patients were: ≥18 years of age; had advanced (locally advanced 12 cycles, followed by every 2 or 3 cycles, and finally 5 ± 1 weeks after incurable or metastatic), histologically confirmed estrogen receptor, completion of therapy. progesterone receptor, and HER2-negative breast cancer; adequate The secondary efficacy endpoints of this study were PFS, DOR, OS, and available historical tumor biopsies (core biopsy or surgical specimen); clinical benefit rate (CBR). PFS was defined as the time from the date of first 0–2 prior therapies for the treatment of advanced breast cancer; and study drug dose to the first documentation of PD or death due to any measurable disease according to Response Evaluation Criteria in Solid cause, whichever occurred first. DOR was defined as the time that response Tumors (RECIST) 1.1 . A minimum of 30 patients who were germline criteria were first met for PR or CR until the date that recurrent or PD BRCA1/2 wild-type and had a basal subtype, as assessed by PAM50, were to disease was objectively documented. OS was defined as the time from the be enrolled into this study. If one or more of these characteristics was date of the first dose of study drug to death due to any cause. CBR was npj Breast Cancer (2022) 45 Published in partnership with the Breast Cancer Research Foundation M.L. Telli et al. defined as the proportion of patients who achieved a BOR of CR, PR, or SD Reporting summary of ≥6 months, measured from the date of first study drug dose. Further information on research design is available in the Nature Research Blood samples for PK analysis of berzosertib were collected pre-dose, Reporting Summary linked to this article. 0.5 h before the end of infusion, at the end of infusion, and at 0.5, 1, 2, 3, and optionally at 7 h after the end of infusion on cycle 1, day 2. A limited berzosertib PK sampling scheme was implemented in this expansion DATA AVAILABILIITY cohort, with samples collected up to 4 h after the start of infusion for all Any requests for data by qualified scientific and medical researchers for legitimate participants and optionally at 8 h; therefore, only a partial AUC up to 4 h research purposes will be subject to the healthcare business of Merck KGaA, Darmstadt, after the start of infusion (AUC ) was estimated for berzosertib. 0–4 Germany Data Sharing Policy. All requests should be submitted in writing to the Berzosertib was administered by i.v. infusion over 60 (±10) min; if the healthcare business of he Merck KGaA, Darmstadt, Germany data sharing portal (https:// total volume of infusion was ≥600 mL, infusion time could be extended up www.merckgroup.com/en/research/our-approach-to-research-and-development/health to 90 min, as tolerated. Tumor biopsies – either historical core or surgical care/clinicaltrials/commitment-responsible-data-sharing.html). When the healthcare busi- specimens, or core biopsy obtained at screening (if the biopsy could be ness of Merck KGaA, Darmstadt, Germany has a co-research, co-development, co- considered standard clinical practice) – were collected for potential marketing, or co-promotion agreement, or when the product has been out-licensed, the exploratory evaluation of correlations between genetic alterations and responsibility for disclosure might be dependent on the agreement between parties. treatment outcomes. Under these circumstances, the healthcare business of Merck KGaA, Darmstadt, Germany will endeavor to gain agreement to share data in response to requests. Biomarker analyses Received: 2 July 2021; Accepted: 16 February 2022; Germline BRCA1/2 mutational status was determined using the BRCAna- lysis assay (Myriad Genetics, Inc., Salt Lake City, UT, USA) and tumor intrinsic subtype was assessed via PAM50 molecular profiling using the Breast Cancer Prognostic Gene Signature Assay (Prosigna®; LabCorp [Covance], Burlington, NC, USA). Exploratory biomarkers – including LOH and TMB, surrogate markers for REFERENCES DNA repair deficiencies – were assessed using FMI’s FoundationOne® CDx 1. Lee, K. J. et al. Exploiting DNA repair defects in triple negative breast cancer to next-generation sequencing (Foundation Medicine Inc., Cambridge, MA, improve cell killing. Ther. Adv. Med. Oncol. 12, 1758835920958354 (2020). USA). The genomic LOH score determined by FMI is assessed based on the 2. Howlader, N., Cronin, K. A., Kurian, A. W. & Andridge, R. 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Darmstadt, Germany, contributed to the analysis and interpretation of PK data. Annick 23. Hall, A. B. et al. Potentiation of tumor responses to DNA damaging therapy by the Seithel-Keuth, PhD, an employee of the healthcare business of Merck KGaA, Darmstadt, selective ATR inhibitor VX-970. Oncotarget 5, 5674–5685 (2014). Germany, contributed to the analysis and interpretation of PK data. Danyi Wang, MD, 24. Middleton, M. R. et al. Phase 1 study of the ATR inhibitor berzosertib (formerly PhD, an employee of EMD Serono, Billerica, MA, USA, provided technical and M6620, VX-970) combined with gemcitabine ± cisplatin in patients with operational support of biomarker sample analysis. Medical writing assistance was advanced solid tumours. Br. J. Cancer 125, 510–519 (2021). provided by Alexander T. Hardy of Bioscript Stirling Ltd, Macclesfield, UK and funded by 25. Shapiro, G. I. et al. Phase 1 study of the ATR inhibitor berzosertib in combination the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: with cisplatin in patients with advanced solid tumours. Br. J. Cancer 125, 520–527 https://doi.org/10.13039/100009945). The trial (including acquisition of data; analysis (2021). and interpretation of data; study supervision, conception, and design; development of 26. Yap, T. A. et al. Phase I trial of first-in-class ATR inhibitor M6620 (VX-970) as methodology; administrative, technical or material support; and writing, review, and/or monotherapy or in combination with carboplatin in patients with advanced solid revision of the manuscript) was sponsored by the healthcare business of Merck KGaA, tumors. J. Clin. Oncol. 38, 3195–3204 (2020). Darmstadt, Germany and Vertex Pharmaceuticals Incorporated., Boston, MA, USA. 27. Konstantinopoulos, P. A. et al. Berzosertib plus gemcitabine versus gemcitabine alone in platinum-resistant high-grade serous ovarian cancer: a multicentre, open-label, randomised, phase 2 trial. Lancet Oncol. 21, 957–968 (2020). AUTHOR CONTRIBUTIONS 28. Terranova, N., Jansen, M., Falk, M. & Hendriks, B. S. Population pharmacokinetics Acquisition of data: R.W., S.R.L., E.D., S.M.T., R.P., T.C.H., A.T., M.T., and G.I.S. Analysis of ATR inhibitor berzosertib in phase I studies for different cancer types. Cancer and interpretation of data: I.D.-P., T.Gr., J.D., R.P., T.Go., R.W., S.R.L., E.D., S.M.T., T.C.H., Chemother. Pharmacol. 87, 185–196 (2020). A.T., M.T., and G.I.S. Study supervision: R.W., S.R.L., R.P., A.T., M.T., and G.I.S. Conception 29. Thomas, A. et al. Therapeutic targeting of ATR yields durable regressions in small and design: R.P. Writing, review, and/or revision of the manuscript: all authors. Read cell lung cancers with high replication stress. Cancer Cell 39, 566–579.e567 (2021). and approved final manuscript: all authors. 30. FDA. FoundationFocus CDxBRCA LOH - P160018/S001, https://www.fda.gov/ medical-devices/recently-approved-devices/foundationfocus-cdxbrca-loh- p160018s001 (2018). COMPETING INTERESTS 31. Foundation Medicine, I. FoundationOne®CDx Technical Information, https://assets. M.L.T.: advisory role: AbbVie, Aduro, Blueprint Medicines Celgene, Daiichi Sankyo, ctfassets.net/w98cd481qyp0/41rJj28gFwtxCwHQxopaEb/2725881bbc67d6f323a Genentech, G1 Therapeutics, Immunomedics, Lilly, Merck & Co., Natera, OncoSec b893851344c4a/FoundationOne_CDx_Label_Technical_Info.pdf. Medical, Pfizer. Institutional research funding from AbbVie, AstraZeneca, Bayer, Biothera, 32. Isakoff, S. J. et al. TBCRC009: a multicenter phase II clinical trial of platinum Calithera, EMD Serono, Billerica, MA USA, Genentech, Merck & Co., OncoSec Medical, monotherapy with biomarker assessment in metastatic triple-negative breast Pfizer, PharmaMar, Tesaro, Vertex. S.M.T.: Institutional research funding from cancer. J. Clin. Oncol. 33, 1902–1909 (2015). AstraZeneca, Lilly, Merck & Co., Nektar, Novartis, Pfizer, Genentech/Roche, Immunome- 33. Pal, S. K. et al. Effect of cisplatin and gemcitabine with or without berzosertib in dics, Exelixis, Bristol-Myers Squibb, Eisai, Nanostring, Cyclacel, Odonate, and Seattle patients with advanced urothelial carcinoma: a phase 2 randomized clinical trial. Genetics; has served as an advisor/consultant to AstraZeneca, Lilly, Merck & Co., Nektar, JAMA Oncol. 7, 1536–1543 (2021). 34. Toledo, L. I. et al. A cell-based screen identifies ATR inhibitors with synthetic lethal Novartis, Pfizer, Genentech/Roche, Immunomedics, Bristol-Myers Squibb, Eisai, Nano- properties for cancer-associated mutations. Nat. Struct. Mol. Biol. 18,721–727 (2011). string, Puma, Sanofi, Celldex, Paxman, Puma, Silverback Therapeutics, G1 Therapeutics, 35. Murga, M. et al. Exploiting oncogene-induced replicative stress for the selective AbbVie, Anthenex, OncoPep, Outcomes4Me, Kyowa Kirin Pharmaceuticals, Daiichi- killing of Myc-driven tumors. Nat. Struct. Mol. Biol. 18, 1331–1335 (2011). Sankyo, Gilead, and Samsung Bioepsis Inc. G.I.S. has received research funding from Eli 36. Su, X. A. et al. RAD21 is a driver of chromosome 8 gain in Ewing sarcoma to Lilly, the healthcare business of EMD Serono, Billerica, MA USA, Merck & Co., and Sierra mitigate replication stress. Genes Dev. 35, 556–572 (2021). Oncology. He has served on advisory boards for Pfizer, Eli Lilly, G1 Therapeutics, Roche, 37. Williamson, C. T. et al. ATR inhibitors as a synthetic lethal therapy for tumours the healthcare business of EMD Serono, Billerica, MA USA, Sierra Oncology, Bicycle deficient in ARID1A. Nat. Commun. 7, 13837 (2016). Therapeutics, Fusion Pharmaceuticals, Cybrexa Therapeutics, Astex, Almac, Ipsen, Bayer, 38. Yap, T. A. et al. First-in-human trial of the oral ataxia telangiectasia and RAD3- Angiex, Daiichi Sankyo, Seattle Genetics, Boehringer Ingelheim, ImmunoMet, Asana, related (ATR) inhibitor BAY 1895344 in patients with advanced solid tumors. Artios, Atrin, Concarlo Holdings, Syros, Zentalis and CytomX Therapeutics. In addition, he Cancer Discov. 11,80–91 (2020). holds a patent entitled, “Dosage regimen for sapacitabine and seliciclib,” also issued to 39. Abkevich, V. et al. Patterns of genomic loss of heterozygosity predict homologous Cyclacel Pharmaceuticals, and a pending patent, entitled, “Compositions and Methods recombination repair defects in epithelial ovarian cancer. Br. J. Cancer 107, for Predicting Response and Resistance to CDK4/6 Inhibition,” together with Liam 1776–1782 (2012). Cornell. M.M.: personal fees from Amgen, grants and personal fees from Roche, grants 40. Pawlyn, C. et al. Loss of heterozygosity as a marker of homologous repair deficiency from AstraZeneca, grants and personal fees from GSK, personal fees and other from in multiple myeloma: a role for PARP inhibition? Leukemia 32,1561–1566 (2018). Novartis, other from Millenium, personal fees, non-financial support and other from 41. Telli, M. L. et al. Homologous recombination deficiency (HRD) score predicts Immunocore, personal fees and other from BMS and Eisai, other from Pfizer, personal response to platinum-containing neoadjuvant chemotherapy in patients with fees, non-financial support and other from MSD, personal fees and other from Rigontec triple-negative breast cancer. Clin. Cancer Res. 22, 3764–3773 (2016). (acquired by MSD), other from Regeneron, personal fees from BiolineRx, personal fees 42. Eisenhauer, E. A. et al. New response evaluation criteria in solid tumours: revised and other from Array Biopharma (now Pfizer), non-financial support and other from RECIST guideline (version 1.1). Eur. J. Cancer 45, 228–247 (2009). Replimune, personal fees from Kineta, and personal fees from Silicon Therapeutics, 43. MedDRA. Medical Dictionary for Regulatory Activities Version 21.0, https://admin. outside the submitted work. S.R.L.: personal fees from Eisai, Shionogi and Prosigna, and new.meddra.org/sites/default/files/guidance/file/dist_file_format_21_0_english. was previously employed by Pfizer, research funding from Pathios Therapeutics, pdf (2018). received travel, accommodation or expenses from Pfizer, Roche, Synthon and Piqur 44. NCI. Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0, https:// Therapeutics, cofounder and stock holding in Mitox Therapeutics. H.-T.A. has served as evs.nci.nih.gov/ftp1/CTCAE/CTCAE_4.03/Archive/CTCAE_4.0_2009-05-29_Quick an advisor/consultant for Bicycle Therapeutics, Biontech, Bayer, Beigene, Servier, Roche Reference_8.5x11.pdf (2009). and Guardant Health, and honoraria from Bicycle Therapeutics, Biontech, Bayer, 45. McLaren, W. et al. The Ensembl Variant Effect Predictor. Genome Biol. 17, 122 Beigene, Servier, Roche and Guardant Health. A.T.: AstraZeneca-Financial support to (2016). academic and hospital institutions for costs associated with academic study chair and 46. Clopper, C. J. & Pearson, E. S. The use of confidence or fiducial limits illustrated in local site costs for OlympiA trial/Travel expenses related to any trial related travel/ the case of the binomial. Biometrika 26, 404–413 (1934). Payments to Institution through Breast International Group for trial conduct in Olympia 47. Brookmeyer, R. & Crowley, J. A confidence interval for the median survival time. trial and through CRO’s for commercial PARP inhibitor trials AstraZeneca with royalties Biometrics 38,29–41 (1982). paid by Institute of Cancer Research with royalties paid for use of PARP inhibitors in DNA deficient cancers, licensee - AstraZeneca. Payments to Institute of Cancer Research and personally through ICR rewards to Inventors scheme. the healthcare business of ACKNOWLEDGEMENTS Merck KGaA, Darmstadt, Germany: local site trial support costs associated with clinical The authors would like to thank patients, investigators, co-investigators, and the study trial. Pfizer: personal fees/Advisory Board related to targeted therapies in DNA repair teams at each of the participating centers and at the healthcare business of Merck deficient cancers. Vertex: personal fees from/Advisory Board related to targeted KGaA, Darmstadt, Germany. The authors thank Vertex Pharmaceuticals for their therapies in DNA repair deficient. Artios: personal fees/Advisory Board related to involvement in the development of berzosertib (formerly M6620, VX-970). Giuseppe targeted therapies in DNA repair deficient cancers. Prime Oncology-Personal fees/ npj Breast Cancer (2022) 45 Published in partnership with the Breast Cancer Research Foundation M.L. Telli et al. Advisory Board related to targeted therapies in DNA repair deficient cancers. ADDITIONAL INFORMATION Medivation: financial support for research at ICR. Breast Cancer Now Charity: grant Supplementary information The online version contains supplementary material funded to study homologous recombination deficient breast and other cancers, BCN available at https://doi.org/10.1038/s41523-022-00406-0. receive payments through AstraZeneca related to PARP inhibitor patents. CRUK: grant funded to study homologous recombination deficient breast and other cancers, CRUK Correspondence and requests for materials should be addressed to Ruth Plummer. receive payments through AstraZeneca related to PARP inhibitor patents/personal fees/ honoraria associated with function as Deputy Chair and reviewer for CRUK Clinical Reprints and permission information is available at http://www.nature.com/ Research committee. Inbiomotion: personal fees/Scientific Ad Board function and stock reprints options. MD Anderson: personal fees/Moon shot Breast Cancer scientific advisory board Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims honoraria. Medscape Education honorarium from Merck & Co. educational grant: in published maps and institutional affiliations. personal fees/speaker for a video series. V.A. has received consulting fees from Daiichi Sankyo and Eisai and research grants from Genentech. E.D. was an employee and stockholder at AstraZeneca subsequent to involvement in this study. T.C.H. has received research funding from Takeda Oncology. R.W. has received research funding from Open Access This article is licensed under a Creative Commons Acerta Pharma and AstraZeneca; served on advisory boards for Puma Biotechnology, Attribution 4.0 International License, which permits use, sharing, Pfizer; and served on speakers’ bureau for Roche Diagnostics. J.F.-P. is an employee of adaptation, distribution and reproduction in any medium or format, as long as you give Ares Trading SA, Eysins, Switzerland, an affiliate of Merck KGaA, Darmstadt, Germany. T. appropriate credit to the original author(s) and the source, provide a link to the Creative Go. and T.Gr. are employees of the healthcare business of Merck KGaA, Darmstadt, Commons license, and indicate if changes were made. The images or other third party Germany. J.D. is an employee of EMD Serono, Billerica MA, USA. P.F.-M.: an employee of material in this article are included in the article’s Creative Commons license, unless EMD Serono, Billerica MA, USA. I.D.-P. was an employee of Ares Trading SA, Eysins, indicated otherwise in a credit line to the material. If material is not included in the Switzerland, an affiliate of Merck KGaA, Darmstadt, Germany, at the time of the study article’s Creative Commons license and your intended use is not permitted by statutory and is currently an employee of GlaxoSmithKline, Zug, Switzerland. R.P. has received regulation or exceeds the permitted use, you will need to obtain permission directly honoraria for attending advisory boards from Pierre Faber, Bayer, Octimet, Clovis from the copyright holder. To view a copy of this license, visit http://creativecommons. Oncology, Novartis, Karus Therapeutics, Biosceptre, BMS, Cybrexa, Ellipses, CV6 org/licenses/by/4.0/. Therapeutics, Astex Therapeutics and Sanofi Aventis. Fees for delivery of educational talks or chairing educational meetings by AstraZeneca, Novartis, Bayer, Tesaro and BMS. Funds to support attendance at conferences from BMS and MSD. © The Author(s) 2022 Published in partnership with the Breast Cancer Research Foundation npj Breast Cancer (2022) 45 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png npj Breast Cancer Springer Journals

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Abstract

www.nature.com/npjbcancer ARTICLE OPEN Phase 1b study of berzosertib and cisplatin in patients with advanced triple-negative breast cancer 1 2 2 3 3 4,5 Melinda L. Telli , Sara M. Tolaney , Geoffrey I. Shapiro , Mark Middleton , Simon R. Lord , Hendrik Tobias Arkenau , 6,7 8 9,16 10 11 12 Andrew Tutt , Vandana Abramson , Emma Dean ,Tufia C. Haddad , Robert Wesolowski , Jordi Ferrer-Playan , 13 13 14 14 12,17 Thomas Goddemeier , Thomas Grombacher , Jennifer Dong , Patricia Fleuranceau-Morel , Ivan Diaz-Padilla and Ruth Plummer Platinum derivatives are commonly used for the treatment of patients with metastatic triple-negative breast cancer (TNBC). However, resistance often develops, leading to treatment failure. This expansion cohort (part C2) of the previously reported phase 1b trial (NCT02157792) is based on the recommended phase 2 dose of the combination of the ataxia-telangiectasia and Rad3- related (ATR) inhibitor berzosertib and cisplatin observed in patients with advanced solid tumors, including TNBC. Forty-seven 2 2 patients aged ≥18 years with advanced TNBC received cisplatin (75 mg/m ; day 1) and berzosertib (140 mg/m ; days 2 and 9), in 21- day cycles. Berzosertib was well tolerated, with a similar toxicity profile to that reported previously for this combination. The overall response rate (90% confidence interval) was 23.4% (13.7, 35.8). No relevant associations were observed between response and gene alterations. Further studies combining ATR inhibitors with platinum compounds may be warranted in highly selected patient populations. npj Breast Cancer (2022) 8:45 ; https://doi.org/10.1038/s41523-022-00406-0 INTRODUCTION germline or somatic BRCA1/2 mutations. Despite some progress being made, there remains a significant unmet medical need to Triple-negative breast cancer (TNBC) accounts for ~10–20% of all improve treatment outcomes for patients with advanced TNBC. patients with breast cancer and is traditionally defined by the lack Ataxia telangiectasia and Rad3-related (ATR) and ataxia- of expression of the estrogen and progesterone receptors, telangiectasia-mutated (ATM) protein kinases are members of alongside no overexpression or amplification of the human 1 the DNA damage response (DDR) family of proteins. Both ATM and epidermal growth factor receptor 2 (HER2) . TNBC has the poorest 2 ATR are key regulators of cell cycle checkpoint control and prognosis amongst all breast cancer subtypes ; the reported predominantly direct repair of DNA via homologous recombina- 5-year survival for patients with any metastatic breast cancer is tion . Loss or inactivation of a single member of the DDR family 3,4 ~27%, compared with 11% in patients with metastatic TNBC .At of proteins has been associated with a greater reliance on other least four different subtypes of breast cancers have been family members to respond to DNA damage, including damage identified according to their gene expression profile, namely: induced by platinum-based chemotherapy. Preclinical experi- 5,6 luminal A, luminal B, HER2-enriched, and basal-like (basal) . ments conducted using human ovarian and breast cancer cell In the setting of advanced TNBC, carboplatin has previously lines suggest that their sensitivity to DNA-damaging agents may demonstrated similar efficacy and a more favorable toxicity profile be increased when used in combination with ATR inhibitors . 7–9 compared to docetaxel , and therefore platinum derivates have Preclinical evidence also suggests that tumor protein 53 (TP53) commonly been used for the treatment of metastatic disease . mutant status correlates with the response to ATR inhibition in However, the treatment options for patients with advanced TNBC 18–20 combination with DNA damaging agents . Since basal breast have expanded in the last few years as new therapeutic cancers often present with a high frequency of TP53 muta- 21,22 modalities, such as immune checkpoint inhibitors and tions , combining ATR inhibitors and DNA-damaging che- 11–13 antibody–drug conjugates, have become available . Poly motherapy is a theoretically efficacious therapeutic approach in (ADP-Ribose) Polymerase (PARP) inhibitors have also been this setting. approved for use in patients with germline Breast Cancer Gene Berzosertib (formerly M6620, VX-970) is an intravenously (i.v.) (BRCA) 1/2-mutated, HER2-negative metastatic breast cancer. This administered, highly potent and selective, first-in-class inhibitor of includes patients with TNBC who have germline BRCA1/2 ATR . Preclinical studies have demonstrated the ability of ATR mutations, with clinical benefits also extending to those with inhibitors to sensitize breast cancer cell lines to platinum-based somatic BRCA1/2 mutations, although it is unclear whether similar chemotherapy, namely cisplatin . The part A and B cohorts of the 14,15 benefits will be observed in patients with TNBC without first-in-human study (NCT02157792) phase 1 trial of berzosertib 1 2 3 4 Stanford University School of Medicine, Stanford, CA, USA. Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA. University of Oxford, Oxford, UK. Sarah 5 6 Cannon Research Institute, HCA Healthcare, London, UK. University College London, London, UK. Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer 7 8 Research and Kings College, London, UK. Guy’s and St Thomas’ NHS Foundation Trust, London, UK. Vanderbilt University Medical Center, Vanderbilt-Ingram Cancer 9 10 11 Center, Nashville, TN, USA. The University of Manchester and The Christie NHS Foundation Trust, Manchester, UK. Mayo Clinic, Rochester, MN, USA. The Ohio State University 12 13 Comprehensive Cancer Center, Columbus, OH, USA. Ares Trading SA, Eysins, Switzerland, an affiliate of Merck KGaA, Darmstadt, Germany. the healthcare business of Merck 14 15 KGaA, Darmstadt, Germany. EMD Serono, Billerica, MA, USA. Newcastle University and Northern Centre for Cancer Care, Newcastle Hospitals NHS Foundation Trust, Newcastle 16 17 upon Tyne, UK. Present address: Oncology R&D, AstraZeneca, Cambridge and Alderley Park, Macclesfield, UK. Present address: GlaxoSmithKline, Zug, Switzerland. email: Ruth.Plummer@newcastle.ac.uk Published in partnership with the Breast Cancer Research Foundation 1234567890():,; M.L. Telli et al. established the recommended phase 2 dose (RP2D) and demon- Table 1. Patient demographics and baseline characteristics. strated its tolerability, both as a single agent and in combination with certain chemotherapies; preliminary signs of efficacy were Characteristic, N (%) unless stated Total N = 47 also observed in patients with a range of solid tumor types, 24,25 including TNBC . The tolerability, preliminary signs of efficacy, Sex and favorable pharmacokinetics (PK) identified in this study have Male 0 26–28 been confirmed in other clinical studies of berzosertib .A Female 47 (100) berzosertib–topotecan combination has also been evaluated in a Ethnicity recent proof-in-concept phase 2 study, reporting an objective Caucasian/White 41 (87.2) response rate of 36% (9/25) and a median duration of response of 6.4 months in patients with SCLC, including platinum-resistant Non-Caucasian/non-White 3 (6.4) patients . Parts A and B of NCT02157792 were dose escalation Age, years; median (range) 48.0 (35–73) studies that established the RP2D of berzosertib in combination Baseline ECOG PS with gemcitabine (part A; berzosertib 210 mg/m [days 2 and 9] in 0 25 (53.2) 2 24 combination with gemcitabine 1000 mg/m [days 1 and 8]) and 1 22 (46.8) cisplatin (part B; berzosertib 140 mg/m [days 2 and 9] in 2 25 combination with cisplatin 75 mg/m [day 1]) in 21-day cycles. Prior anticancer therapy Here we report the results from the C2 expansion cohort of the Chemotherapy 45 (95.7) same study, which investigated the safety and tolerability, efficacy, Immunotherapy 1 (2.1) PK, and potential predictive biomarkers of berzosertib in Other 11 (23.4) combination with cisplatin in patients with advanced TNBC whose Missing 2 (4.3) tumors were germline BRCA1/2 wild-type and basal subtype. Number of previous anticancer therapy regimens Neoadjuvant 16 (34.0) RESULTS Adjuvant 27 (57.4) Patient demographics and disposition st 1 line, metastatic disease 24 (51.1) Forty-seven patients were enrolled into this study, all of whom nd 2 line, metastatic disease 10 (21.3) were included in the safety analysis set (SAF) and modified full nd >2 line, metastatic disease 5 (10.6) analysis set (mFAS) for efficacy (Table 1). The PK analysis set (PAS) included all enrolled patients who received at least one dose of Missing 2 (4.3) berzosertib and provided at least one measurable post-dose TP53 concentration; 41 patients were included in the PAS, with 6 Wild type 2 (4.3) patients excluded as they did not have a measurable post-dose PK Mutant 34 (72.3) berzosertib concentration. The modified primary efficacy set Missing 11 (23.4) (mPES) included all patients in the mFAS who were basal subtype BRCA1/2 and BRCA1/2 germline wild-type; 35 patients were included in the mPES, with 12 patients excluded due to a lack of BRCA1/2 gWT Wild type 31 (66) status data or were not basal subtype. Among all patients, 34 Mutant 5 (10.6) (72.3%) were TP53 mutant; 2 (4.3%) were TP53 wild-type; 31 (66%) Missing 11 (23.4) were BRCA1/2 germline wild-type; and 36 (76.6%) were basal Basal subtype subtype, based on Prediction Analysis of Microarray 50 (PAM50). In Yes 36 (76.6) the 7 patients who were not basal subtype, 4 (57.1%) had a TP53 mutation, 1 (14.3%) was TP53 wild-type and 2 (28.6%) had an No 7 (14.9) unknown TP53 mutational status; in the 36 (76.6%) patients who Missing 4 (8.5) were basal subtype, 29 (81%) had a TP53 mutation, 1 (3%) was ATM ataxia-telangiectasia mutated, BRCA1/2 breast cancer gene 1/2, ECOG TP53 wild-type, and 6 (17%) had an unknown TP53 mutational PS Eastern Cooperative Oncology Group Performance Status, TP53 tumor status. Four patients had an unknown subtype (Table 2). protein 53. In all, 24 (51.1%) patients had previously received only one line Only patients with biomarker status determined by FoundationOne® CDx of therapy for metastatic disease, 10 (21.3%) patients had received next generation sequencing were reported. two lines of therapy, and 5 (10.6%) received more than two lines Patients with unknown BRCA1/2 status were prospectively tested at of therapy for metastatic disease. screening by BRCAnalysis assay (Myriad Genetics); patients that were found All 47 patients in the mFAS received at least one dose of to be BRCA1/2 germline mutant were still enrolled in the study. Assessment for basal subtype was performed retrospectively via PAM50 berzosertib, 46 (97.9%) received at least one dose of cisplatin, and analysis (Prosigna). 12 (25.5%) received at least one dose of carboplatin; the patient who received berzosertib without cisplatin received at least one dose of carboplatin. Thirty-eight (80.9%) patients completed treatment with berzosertib, while nine (19.1%) discontinued treatment, primarily due to patient decision (four, 8.5%) or adverse events (AEs; two, 4.3%). Sixteen patients (34%) discon- Table 2. TP53 mutational status. tinued cisplatin, primarily due to AEs (12.8%) and remained on TP53 status Basal subtype (N = 36) Non-basal subtype (N = 7) berzosertib monotherapy until PD. The median (range) duration of treatment for berzosertib in combination with cisplatin was 15.0 (5 Wild type 1 (3.0) 1 (14.3) cycles) (2.0, 137.1) weeks. No patients died during this study. Mutant 29 (81.0) 4 (57.1) Missing 6 (17.0) 2 (28.6) Efficacy TP53 tumor protein 53. Forty-seven patients were included in the mFAS; however four patients were non-evaluable. The objective response rate (ORR npj Breast Cancer (2022) 45 Published in partnership with the Breast Cancer Research Foundation 1234567890():,; M.L. Telli et al. [90% confidence interval (CI)]) was 11/47 (23.4%) patients (13.7, of CR were previously treated only in the neoadjuvant/adjuvant 35.8), the best overall response (BOR) was complete response (CR) setting, while no patients who had received more than two lines for two (4.3%) patients, partial response (PR) for nine (19.1%) of therapy for metastatic disease achieved a response. The median duration of response (DOR; [90% CI]) was patients, and stable disease (SD) for 18 (38.3%) patients (Table 3 6.0 months (5.1, not defined). Median progression-free survival and Fig. 1a); all responses were confirmed. For patients with SD (PFS; [90% CI]) was 4.0 months (2.8, 6.0), and median overall (N = 18), 3 patients (16.7%) progressed within 3 months, 10 survival (OS; [90% CI]) was 12.4 months (7.8, 14.5). (55.6%) patients progressed within 3–6 months, and 5 (27.8%) Similar results were observed for the mPES: the ORR (90% CI) patients progressed within 6–12 months. BOR was also retro- was 9/35 (25.7%) patients (14.1, 40.6), 2 (5.7%) patients had a BOR spectively stratified by prior lines of treatment for metastatic of CR, 7 (20.0%) had a BOR of PR, and 15 (42.9%) had a BOR of SD; disease (Supplementary Table 1); all patients who achieved a BOR 10 (28.6%) patients had a BOR of PD. The ORR for patients who were germline BRCA1/2 wild-type vs mutant were 7/31 (22.6%) Table 3. Efficacy responses (modified full analysis set, N = 47). patients vs 2/5 (40.0%) patients, respectively, while for patients who were basal subtype vs those who were not, the ORRs were Efficacy outcome Patients, n (%) unless stated 9/36 (25.0%) patients vs 1/7 (14.3%) patients, respectively. However, no formal statistical comparison for these subgroups BOR was made. Further information on ORR by biomarker status can be CR 2 (4.3) found in Table 4. PR 9 (19.1) SD 18 (38.3) Safety and tolerability PD 14 (29.8) A summary of treatment-emergent AEs (TEAEs) is presented in Not evaluable 4 (8.5) Table 5. The most common TEAEs, which occurred in more than ORR, N (%), (90% CI) 11 (23.4) (13.7, 35.8) 50% of patients, were nausea (N = 39, 83.0%), fatigue (N = 32, DCR, N (%), (90% CI) 29 (61.7) (48.7, 73.6) 68.1%), neutropenia (N = 29, 61.7%), and vomiting (N = 28, 59.6%); a full list of TEAEs affecting ≥20% of patients can be found in Median PFS (months), (90% CI) 4.0 (2.8, 6.0) Table 5. TEAEs of grade ≥3 occurred in 32 patients (62.1%). TEAEs Median OS (months), (90% CI) 12.4 (7.8, 14.5) of grade ≥3 occurring in more than 10% of patients were Median DOR (months), (90% CI) 6.0 (5.1, nd) neutropenia (N = 18, 38.3%), anemia (N = 12, 25.5%), thrombocy- DCR was defined as the proportion of patients with disease control, topenia (N = 6, 12.8%), and vomiting (N = 6, 12.8%). Febrile defined as a BOR of CR, PR, or SD. neutropenia occurred in two (4.3%) patients. Forty-five (95.7%) BOR best overall response, CI confidence interval, CR complete response, patients had a berzosertib-related TEAE; of these, 27 (57.4%) had a DCR disease control rate, DOR duration of response, nd not defined, ORR related TEAE of grade ≥3. There were no notable adverse events overall response rate, OS overall survival, PD progressive disease, PFS relating to laboratory results, vital signs or electrocardiogram progression-free survival, PR partial response, SD stable disease. (ECG) measurements. a b 20 CR PD PR –20 SD NE –40 –60 –80 –100 ** TMB High level TMB Intermediate level TMB Low level TMB LOH High level LOH LOH Intermediate level LOH Low level Data unavailable TP53 p53-pathway BRCA1 Mutant Wild type BRCA2 Data unavailable ATM ARID1A CR PR SD PD TMB intermediate level TMB low level LOH high level LOH low level Unknown Data unavailable 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Treatment duration (months) Fig. 1 Best percentage change in tumor size from baseline and tumor response by LOH and TMB scores (modified full analysis set). a Best percentage change in tumor size from baseline, b tumor response by LOH and TMB scores. Patients without on-treatment target lesion measurements are not shown in Fig. 1a. Patients without response assessments are not shown in Fig. 1b. All response categories were determined according to RECIST 1.1 criteria. Full details of mutations can be found in Supplementary Table 5. CR complete response, LOH loss of heterozygosity, PD progressive disease, PR partial response, RECIST Response Evaluation Criteria in Solid Tumors, SD stable disease, TMB tumor mutational burden. Published in partnership with the Breast Cancer Research Foundation npj Breast Cancer (2022) 45 Maximum percentage change in tumor size from baseline Patients M.L. Telli et al. confirmed response, compared with only 1 of the 5 patients with Table 4. ORR for selected biomarker subgroups; modified full analysis an intermediate TMB score. set (N = 47). A 40-year-old female patient with grade 3, metastatic, BRCA1/2 negative TNBC achieved a CR with a duration of 28.6 months, Gene Patients, n Responses, n ORR, % (90% CI) remaining in CR at the end of the study. The patient achieved a TP53 BOR of CR despite disease progression on previous chemother- apeutic treatment in the (neo)adjuvant setting. Further assess- Wild type 2 0 0.0 (0.0, 77.6) ment of the biomarker status of this patient revealed Mutant 34 9 26.5 (14.6, 41.6) heterozygous germline mutations in genes including adenovirus ARID1A E1A-associated cellular p300 transcriptional co-activator protein Wild type 34 9 26.5 (14.6, 41.6) (EP300), DNA polymerase delta 1, catalytic subunit (POLD1), and Mutant 2 0 0.0 (0.0, 77.6) Tumor Growth Factor Beta Receptor 2 (TGFBR2), all variants of unknown significance. Archival tumor demonstrated low LOH and ATM TMB scores, somatic TP53 mutation and several gene amplification Wild type 31 8 25.8 (13.5, 41.8) events relating to MYC (copy number 18), CCNE1 (Cyclin E1; copy Mutant 5 1 20.0 (1.0, 65.7) number 14), and RAD21 (copy number 18). Germline BRCA1/2 Wild type 31 7 22.6 (11.1, 38.3) Pharmacokinetics Mutant 5 2 40.0 (7.6, 81.1) The PAS included 41 patients, with six patients excluded because Basal subtype their post-dose berzosertib concentration was outside the limit of Yes 36 9 25.0 (13.7, 39.6) quantification. The administered i.v. berzosertib dose of 140 mg/ m was within the dose range that has previously shown dose- ARID1A AT-rich interaction domain 1A, ATM ataxia-telangiectasia-mutated, dependent berzosertib PK as monotherapy or in combination with BRCA1/2 breast cancer gene 1/2, CI confidence interval, ORR overall 24–26 either carboplatin or cisplatin . The observed berzosertib response rate, PAM50 Prediction Analysis of Microarray 50, TP53 tumor concentration data in this expansion cohort were generally protein 53. Only patients with biomarker status determined by FoundationOne® CDx consistent with those reported previously at the same dose next-generation sequencing were reported. level . Cisplatin had no apparent effect on berzosertib PK Basal subtype was determined via PAM50 analysis (Prosigna) and was (Supplementary Fig. 1). Key berzosertib PK parameters from this performed retrospectively. study, presented as geometric mean (geometric coefficient of variance), were as follows: maximum observed concentration (C [ng/mL]) – 555 (42.9%); area under the curve (AUC) from max In all, 15 (31.9%) patients had a serious TEAE, with 13 (27.7%) start of infusion to the 4-h sampling time after start of infusion having a grade ≥3 serious TEAE. Of these patients, 10 (21.3%) (AUC [ng.h/mL]) – 1110 (26.4%). The C in this expansion 0–4 max reported a serious TEAE related to berzosertib, 8 (17%) related to cohort was slightly lower than the 652 ng/mL (25%) and 854 ng/ cisplatin, and 2 (4.3%) related to carboplatin. mL (63%) observed in the lead-in period and in the berzosertib In total, 11 (23.4%) patients experienced a TEAE leading to a and cisplatin combination cohort, respectively, at the same dose dose reduction in at least one study drug (3 [6.4%], 8 [17.0%], and level in part B. The partial AUC was ~23% of the reported 0–4 1 [2.1%] TEAEs leading to permanent dose reduction were related AUC in part B . 0–∞ to berzosertib, cisplatin, and carboplatin, respectively). In total, 24 (51.1%) patients experienced a TEAE leading to temporary discontinuation of at least one study drug (21 [44.7%], DISCUSSION 15 [31.9%], and 5 [10.6%] TEAEs leading to temporary disconti- In this dose expansion cohort study, berzosertib 140 mg/m (days nuation were related to berzosertib, cisplatin, and carboplatin, 2 and 9) administered alongside cisplatin 75 mg/m (day 1) in 21- respectively). Five (10.6%) patients in this expansion cohort day cycles was well tolerated in patients with advanced TNBC. The permanently discontinued berzosertib during the study due to safety profile of this combination was broadly consistent with that TEAEs, three of whom discontinued due to berzosertib-related of the individual agents and no new or unexpected safety signals TEAEs (one patient each experienced neutropenia [grade 2], were identified for berzosertib . Although a high rate of anemia and thrombocytopenia [both grade 3], and peripheral treatment interruptions was observed with berzosertib, these neuropathy [grade 2]). did not translate into dose reductions or permanent treatment discontinuation. The rate of bone marrow toxicity observed in this Biomarkers study with a limited number of participants may indicate the No conclusive association was identified between clinical outcome potential of ATR inhibition to increase the hematologic toxicity of (ORR or PFS) and the mutational status of TP53, AT-rich interaction cisplatin and may be an on-target effect. However, these toxicities domain 1A (ARID1A), ATM or BRCA1/2 (Table 4 and Supplementary were generally manageable and did not result in significant dose Table 2). Post-hoc exploratory biomarker assessments of loss of reductions or treatment discontinuations. heterozygosity (LOH) status and tumor mutational burden (TMB) The observed PK data were generally consistent with the PK 30,31 28 using Foundation Medicine’s (FMI) FoundationOne® CDx assay data reported previously at the same dose levels . A population in these patients did not identify any statistically significant PK model built based on pooled data from two phase 1 studies, association between LOH and response or TMB and response (Fig. including this expansion cohort, suggested that administration of 1b). However, 7 of the 11 patients with a confirmed response had cisplatin does not affect observed berzosertib PK parameters . a high LOH score and 7 of the 16 total patients with a high LOH Although the effects of TNBC tumor type on clearance were score responded to treatment, compared with only 1 of the 12 estimated in the model, an association between tumor type and patients with a low LOH score. Although the association was not PK is not anticipated . statistically significant (p = 0.09), the results suggest an enrich- With the implicit caveats associated with cross-trial compar- ment of responders in tumors with high LOH (OR = 7.96) isons, the response rate observed in this expansion cohort (ORR: (Supplementary Table 3). No patients had a tumor with a high 23.4%; DOR: 6.0 months) was broadly consistent with those TMB score. In all, 7 of the 27 patients with a low TMB score had a observed in historical studies conducted in patients with npj Breast Cancer (2022) 45 Published in partnership with the Breast Cancer Research Foundation M.L. Telli et al. Table 5. Overview of TEAEs for berzosertib and cisplatin (safety analysis set, N = 47). Patients, N (%) Berzosertib + Cisplatin Berzosertib + Cisplatin Any grade Grade ≥3 N = 47 N = 47 TEAE 47 (100) 36 (76.6) Berzosertib-related TEAE 45 (95.7) 27 (57.4) Cisplatin or carboplatin-related TEAE 47 (100) 31 (66.0) Berzosertib or cisplatin or carboplatin-related TEAE 47 (100) 32 (68.1) TEAEs occurring in ≥20% of patients Nausea 39 (83.0) 4 (8.5) Fatigue 32 (68.1) 1 (2.1) Neutropenia 29 (61.7) 18 (38.3) Vomiting 28 (59.6) 6 (12.8) Tinnitus 21 (44.7) 0 Anemia 19 (40.4) 12 (25.5) Headache 18 (38.3) 0 Diarrhea 16 (34.0) 0 Constipation 14 (29.8) 0 Dizziness 11 (23.4) 0 Decreased appetite 10 (21.3) 0 Serious TEAE 15 (31.9) 13 (27.7) Berzosertib-related serious TEAE 10 (21.3) 8 (17.0) Cisplatin or carboplatin-related serious TEAE 10 (21.3) 8 (17.0) Berzosertib or cisplatin or carboplatin-related serious TEAE 10 (21.3) 8 (17.0) TEAEs leading to permanent discontinuation of treatment TEAE leading to permanent discontinuation of berzosertib 5 (10.6) NR Berzosertib-related TEAE leading to permanent discontinuation of berzosertib 3 (6.4) NR Cisplatin-related TEAE leading to permanent discontinuation of cisplatin 8 (17.0) NR Carboplatin-related TEAE leading to permanent discontinuation of carboplatin 3 (6.4) NR TEAE leading to a dose reduction in at least one study drug 11 (23.4) NR Berzosertib-related TEAE leading to dose reduction in berzosertib 3 (6.4) NR Cisplatin-related TEAE leading to dose reduction in cisplatin 8 (17.0) NR Carboplatin-related TEAE leading to dose reduction in carboplatin 1 (2.1) NR TEAE leading to temporary discontinuation of at least one study drug 24 (51.1) NR Berzosertib-related TEAE leading to temporary discontinuation of berzosertib 21 (44.7) NR Cisplatin-related TEAE leading to temporary discontinuation of cisplatin 15 (31.9) NR Carboplatin-related TEAE leading to temporary discontinuation of carboplatin 5 (10.6) NR TEAE leading to death 0 0 NR not reported, TEAE treatment-emergent adverse event. advanced TNBC treated with platinum-based therapy (TNT trial, p53 pathway impairment. Several co-occurring DDR alterations 7,32 carboplatin ORR: 31.4%; TBCRC009 trial, ORR: 25.6%) . may be necessary to confer sensitivity to the combination of ATR Although preclinical evidence suggested a potent synergistic inhibition and platinum-derived chemotherapeutics. effect of berzosertib and cisplatin on cancer cell survival, One patient with TNBC and several co-occurring DDR alterations particularly in tumors with TP53 mutations, this was not observed experienced a CR lasting for 28.6 months. Further assessment of 18–20 with the berzosertib and cisplatin doses utilized in this study . the biomarker status of this patient revealed a number of The lower dose of berzosertib used in this study may have been amplification events relating to MYC, CCNE1, and RAD21. This insufficient for target engagement. For instance, a Phase 2 proof- exceptional response might be explained in part by the presence of-concept study investigating a dose of 210 mg/m of berzosertib of these specific gene amplifications. Overexpression of MYC and in combination with topotecan demonstrated durable tumor CCNE1 (Cyclin E1) have been shown to increase replication stress, 29 34,35 regression in patients with small-cell neuroendocrine cancers , thus sensitizing tumors to ATR inhibition . The role of RAD21 is whereas no benefit in PFS was shown in a Phase 2 study less clear in this context, as up-regulation of RAD21 has been investigating a dose of 90 mg/m berzosertib in combination with shown to mitigate replication stress arising from MYC over- 33 36 gemcitabine in patients with advanced urothelial carcinoma . expression . Future research may explain the complex interplay Additionally, patients in the clinical setting are likely to have between co-occurring gene amplifications and ATR inhibition. tumors with complex genetic aberrations; hence, solely assessing Taken together, no conclusive associations were observed for TP53 mutational status may not provide a robust assessment of gene alterations linked to higher susceptibility to ATR inhibition or Published in partnership with the Breast Cancer Research Foundation npj Breast Cancer (2022) 45 M.L. Telli et al. increased reliance on ATR in preclinical experiments, such as ATM unknown before screening, BRCA1/2 status was determined by central prospective germline testing during screening, and patients found to be and ARID1A alterations . This may be due to the low patient germline BRCA1/2 mutant were still enrolled. If possible, assessment of numbers; for example, there were only five patients with an ATM basal subtype was performed retrospectively. mutation (Supplementary Table 4). However, an enrichment of Prior taxane and/or an anthracycline chemotherapy in the metastatic responses would have been expected in patients with ATM loss, setting was allowed, alongside one other non-platinum-based chemother- which raises questions related to the functionality of ATM, or how apy in the first- or second-line (no restrictions were placed on prior this is defined (i.e. based on loss-of-function mutation, mono- immunotherapy or targeted treatment in the metastatic setting, unless allelic vs bi-allelic loss, or protein expression). Other studies have combined with a cytotoxic agent). pointed towards such an association between ATM protein loss Key exclusion criteria included: any prior platinum therapy in the and response to ATR inhibition . The identification of biomarkers metastatic setting (adjuvant or neoadjuvant platinum-based chemother- apy was permitted if this was completed within 6 months of screening); of response to ATR inhibitors continues to be a very active field of relapse within 3 months of completion of prior adjuvant or neoadjuvant research. chemotherapy; known BRCA1/2 germline mutations, either determined As LOH can indicate the presence of historical homologous and documented prior to screening or determined during screening; and 39,40 recombination deficiency and has also been reported to documented intrinsic subtype other than basal by PAM50. predict response to platinum-based neoadjuvant chemotherapy in Full inclusion and exclusion criteria are provided in the supplementary patients with TNBC , an exploratory biomarker analysis focused information. on evaluating genetic alterations and genomic signatures was conducted in this trial. Interestingly, there were a greater number Treatments of clinical responses in patients with a high LOH status (7/16) The patients enrolled in this cohort received the RP2D established in part within this patient population compared with patients with a low 25 2 B ; following enrollment, patients received berzosertib (140 mg/m )on LOH status (1/12). 2 days 2 and 9, ~24 h after receiving cisplatin (75 mg/m ; day 1) in 21-day In conclusion, the combination of berzosertib and cisplatin in cycles. patients with advanced, pretreated TNBC was well tolerated. A patient could receive berzosertib in combination with carboplatin if Although the observed efficacy signal does not warrant further they had not progressed but were unable to tolerate treatment due to toxicities associated with cisplatin, or it was considered by the Investigator development of the present combination and dose in patients to be in their best interest. The starting doses following switching would with TNBC in a phase 2/3 setting, the clinical evaluation of be berzosertib (90 mg/m ) plus carboplatin (AUC 5 mg/min/mL). berzosertib in a very selective sub-population of patients with Patients received treatment until PD, unacceptable toxicity, withdrawal, breast cancer might be of interest to confirm the role of certain or non-compliance with study protocol. genetic or molecular markers, such as LOH. Clinical trials evaluating berzosertib in combination with DNA damage- Objectives inducing chemotherapy, such as topotecan, are ongoing in a The primary objectives of this study were to evaluate the safety, variety of solid tumors including small-cell lung cancer. tolerability, and preliminary efficacy of berzosertib when combined with cisplatin in patients with advanced, basal, germline BRCA1/2 wild-type TNBC, with or without TP53 mutations. Exploratory objectives of this study METHODS included the evaluation of biomarkers potentially associated with response Study design to berzosertib in combination with cisplatin. This was a multicenter, open-label, non-randomized, first-in-human, phase 1 study conducted in six parts (A, B, B2, C1, C2, C3; NCT02157792, Assessments and endpoints registered 06 June 2014). Part C2 was a single-arm, dose expansion cohort evaluating the safety and preliminary efficacy of berzosertib combined The primary safety endpoints were TEAEs; clinical laboratory values with cisplatin in patients with advanced TNBC using the berzosertib RP2D (chemistry, hematology, urinalysis, coagulation); ECG; and vital signs. TEAEs identified in part B. Patients were enrolled across five sites in the UK and 12 were defined as any AEs that were reported, or worsened, on or after study in the USA, between 09 December 2015 (study initiation date) and 11 drug initiation, through the safety follow-up visit. Serious TEAEs were March 2020 (study completion date, when the final patient completed defined as any AEs that were a congenital or birth abnormality, resulted in their last visit). persistent or significant disability or incapacity, required or prolonged in- This study was conducted in accordance with the ethical principles of patient hospitalization, were life-threatening or resulted in death, or were the International Council for Harmonisation guideline for Good Clinical otherwise deemed medically important. Related TEAEs were defined as any AE reported by the Investigator to have a relationship to study Practice and the Declaration of Helsinki, as well as with applicable local treatment, or where the relationship was unknown. regulations. The Clinical Study Protocol and all required associated All AEs were coded according to the Medical Dictionary for Regulatory documents were approved by the following responsible Institutional Activities V21.0 and graded according to the National Cancer Institute Review Boards (IRB) or Independent Ethics Committees of the individual Common Terminology Criteria for Adverse Events v4.0 . study sites: The Washington University in St. Louis IRB, Vanderbilt The primary efficacy endpoint of this study was the ORR, defined as the University IRB, North East – Tyne & Wear South Research Ethics Committee, proportion of participants with a BOR of PR or CR (summarized as objective Northwestern University Biomedical IRB, Stanford University Administrative response [OR] according to RECIST 1.1), where both PR and CR were Panels on Human Subjects in Medical Research Board, Greenville Health confirmed by repeat assessments performed no less than 4 weeks after the System IRB, Mayo Clinic IRB, The University Hospitals IRB, US Oncology IRB, criteria for response was first met. NRES Committee North East – Sunderland, Dana Farber Cancer Institute Tumor assessments were performed from baseline until either end of IRB, Western IRB. All patients were required to provide written informed treatment or PD using RECIST 1.1 guidelines. Initial disease was consent prior to enrollment. documented using baseline imaging scans (computed tomography or magnetic resonance imaging) taken within 14 days prior to the first dose of Patients study drug; imaging was repeated at the end of every 2 cycles for the first Eligible patients were: ≥18 years of age; had advanced (locally advanced 12 cycles, followed by every 2 or 3 cycles, and finally 5 ± 1 weeks after incurable or metastatic), histologically confirmed estrogen receptor, completion of therapy. progesterone receptor, and HER2-negative breast cancer; adequate The secondary efficacy endpoints of this study were PFS, DOR, OS, and available historical tumor biopsies (core biopsy or surgical specimen); clinical benefit rate (CBR). PFS was defined as the time from the date of first 0–2 prior therapies for the treatment of advanced breast cancer; and study drug dose to the first documentation of PD or death due to any measurable disease according to Response Evaluation Criteria in Solid cause, whichever occurred first. DOR was defined as the time that response Tumors (RECIST) 1.1 . A minimum of 30 patients who were germline criteria were first met for PR or CR until the date that recurrent or PD BRCA1/2 wild-type and had a basal subtype, as assessed by PAM50, were to disease was objectively documented. OS was defined as the time from the be enrolled into this study. If one or more of these characteristics was date of the first dose of study drug to death due to any cause. CBR was npj Breast Cancer (2022) 45 Published in partnership with the Breast Cancer Research Foundation M.L. Telli et al. defined as the proportion of patients who achieved a BOR of CR, PR, or SD Reporting summary of ≥6 months, measured from the date of first study drug dose. Further information on research design is available in the Nature Research Blood samples for PK analysis of berzosertib were collected pre-dose, Reporting Summary linked to this article. 0.5 h before the end of infusion, at the end of infusion, and at 0.5, 1, 2, 3, and optionally at 7 h after the end of infusion on cycle 1, day 2. A limited berzosertib PK sampling scheme was implemented in this expansion DATA AVAILABILIITY cohort, with samples collected up to 4 h after the start of infusion for all Any requests for data by qualified scientific and medical researchers for legitimate participants and optionally at 8 h; therefore, only a partial AUC up to 4 h research purposes will be subject to the healthcare business of Merck KGaA, Darmstadt, after the start of infusion (AUC ) was estimated for berzosertib. 0–4 Germany Data Sharing Policy. All requests should be submitted in writing to the Berzosertib was administered by i.v. infusion over 60 (±10) min; if the healthcare business of he Merck KGaA, Darmstadt, Germany data sharing portal (https:// total volume of infusion was ≥600 mL, infusion time could be extended up www.merckgroup.com/en/research/our-approach-to-research-and-development/health to 90 min, as tolerated. Tumor biopsies – either historical core or surgical care/clinicaltrials/commitment-responsible-data-sharing.html). When the healthcare busi- specimens, or core biopsy obtained at screening (if the biopsy could be ness of Merck KGaA, Darmstadt, Germany has a co-research, co-development, co- considered standard clinical practice) – were collected for potential marketing, or co-promotion agreement, or when the product has been out-licensed, the exploratory evaluation of correlations between genetic alterations and responsibility for disclosure might be dependent on the agreement between parties. treatment outcomes. Under these circumstances, the healthcare business of Merck KGaA, Darmstadt, Germany will endeavor to gain agreement to share data in response to requests. Biomarker analyses Received: 2 July 2021; Accepted: 16 February 2022; Germline BRCA1/2 mutational status was determined using the BRCAna- lysis assay (Myriad Genetics, Inc., Salt Lake City, UT, USA) and tumor intrinsic subtype was assessed via PAM50 molecular profiling using the Breast Cancer Prognostic Gene Signature Assay (Prosigna®; LabCorp [Covance], Burlington, NC, USA). Exploratory biomarkers – including LOH and TMB, surrogate markers for REFERENCES DNA repair deficiencies – were assessed using FMI’s FoundationOne® CDx 1. Lee, K. J. et al. Exploiting DNA repair defects in triple negative breast cancer to next-generation sequencing (Foundation Medicine Inc., Cambridge, MA, improve cell killing. Ther. Adv. Med. Oncol. 12, 1758835920958354 (2020). USA). The genomic LOH score determined by FMI is assessed based on the 2. Howlader, N., Cronin, K. A., Kurian, A. W. & Andridge, R. 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K., Pollard, J. R. & Curtin, N. J. The impact of p53 dysfunction in ATR spectrometry methods in compliance with standard operating procedures. inhibitor cytotoxicity and chemo- and radiosensitisation. Cancers (Basel) 10, 275 All PK analyses was conducted using standard non-compartmental (2018). analyses methods. Published in partnership with the Breast Cancer Research Foundation npj Breast Cancer (2022) 45 M.L. Telli et al. 21. Carey, L. A. et al. Race, breast cancer subtypes, and survival in the Carolina Breast Locatelli, PhD, an employee of the healthcare business of Merck KGaA, Darmstadt, Cancer Study. JAMA 295, 2492–2502 (2006). Germany, contributed to the analysis and interpretation of the biomarker results. Bart 22. Bertheau, P. et al. p53 in breast cancer subtypes and new insights into response Hendriks, PhD, a former employee of the healthcare business of Merck KGaA, to chemotherapy. Breast 22, S27–S29 (2013). Darmstadt, Germany, contributed to the analysis and interpretation of PK data. Annick 23. Hall, A. B. et al. Potentiation of tumor responses to DNA damaging therapy by the Seithel-Keuth, PhD, an employee of the healthcare business of Merck KGaA, Darmstadt, selective ATR inhibitor VX-970. Oncotarget 5, 5674–5685 (2014). Germany, contributed to the analysis and interpretation of PK data. Danyi Wang, MD, 24. Middleton, M. R. et al. Phase 1 study of the ATR inhibitor berzosertib (formerly PhD, an employee of EMD Serono, Billerica, MA, USA, provided technical and M6620, VX-970) combined with gemcitabine ± cisplatin in patients with operational support of biomarker sample analysis. Medical writing assistance was advanced solid tumours. Br. J. Cancer 125, 510–519 (2021). provided by Alexander T. Hardy of Bioscript Stirling Ltd, Macclesfield, UK and funded by 25. Shapiro, G. I. et al. Phase 1 study of the ATR inhibitor berzosertib in combination the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: with cisplatin in patients with advanced solid tumours. Br. J. Cancer 125, 520–527 https://doi.org/10.13039/100009945). The trial (including acquisition of data; analysis (2021). and interpretation of data; study supervision, conception, and design; development of 26. Yap, T. A. et al. Phase I trial of first-in-class ATR inhibitor M6620 (VX-970) as methodology; administrative, technical or material support; and writing, review, and/or monotherapy or in combination with carboplatin in patients with advanced solid revision of the manuscript) was sponsored by the healthcare business of Merck KGaA, tumors. J. Clin. Oncol. 38, 3195–3204 (2020). Darmstadt, Germany and Vertex Pharmaceuticals Incorporated., Boston, MA, USA. 27. Konstantinopoulos, P. A. et al. Berzosertib plus gemcitabine versus gemcitabine alone in platinum-resistant high-grade serous ovarian cancer: a multicentre, open-label, randomised, phase 2 trial. Lancet Oncol. 21, 957–968 (2020). AUTHOR CONTRIBUTIONS 28. Terranova, N., Jansen, M., Falk, M. & Hendriks, B. S. Population pharmacokinetics Acquisition of data: R.W., S.R.L., E.D., S.M.T., R.P., T.C.H., A.T., M.T., and G.I.S. Analysis of ATR inhibitor berzosertib in phase I studies for different cancer types. Cancer and interpretation of data: I.D.-P., T.Gr., J.D., R.P., T.Go., R.W., S.R.L., E.D., S.M.T., T.C.H., Chemother. Pharmacol. 87, 185–196 (2020). A.T., M.T., and G.I.S. Study supervision: R.W., S.R.L., R.P., A.T., M.T., and G.I.S. Conception 29. Thomas, A. et al. Therapeutic targeting of ATR yields durable regressions in small and design: R.P. Writing, review, and/or revision of the manuscript: all authors. Read cell lung cancers with high replication stress. Cancer Cell 39, 566–579.e567 (2021). and approved final manuscript: all authors. 30. FDA. FoundationFocus CDxBRCA LOH - P160018/S001, https://www.fda.gov/ medical-devices/recently-approved-devices/foundationfocus-cdxbrca-loh- p160018s001 (2018). COMPETING INTERESTS 31. Foundation Medicine, I. FoundationOne®CDx Technical Information, https://assets. M.L.T.: advisory role: AbbVie, Aduro, Blueprint Medicines Celgene, Daiichi Sankyo, ctfassets.net/w98cd481qyp0/41rJj28gFwtxCwHQxopaEb/2725881bbc67d6f323a Genentech, G1 Therapeutics, Immunomedics, Lilly, Merck & Co., Natera, OncoSec b893851344c4a/FoundationOne_CDx_Label_Technical_Info.pdf. Medical, Pfizer. Institutional research funding from AbbVie, AstraZeneca, Bayer, Biothera, 32. Isakoff, S. J. et al. TBCRC009: a multicenter phase II clinical trial of platinum Calithera, EMD Serono, Billerica, MA USA, Genentech, Merck & Co., OncoSec Medical, monotherapy with biomarker assessment in metastatic triple-negative breast Pfizer, PharmaMar, Tesaro, Vertex. S.M.T.: Institutional research funding from cancer. J. Clin. Oncol. 33, 1902–1909 (2015). AstraZeneca, Lilly, Merck & Co., Nektar, Novartis, Pfizer, Genentech/Roche, Immunome- 33. Pal, S. K. et al. Effect of cisplatin and gemcitabine with or without berzosertib in dics, Exelixis, Bristol-Myers Squibb, Eisai, Nanostring, Cyclacel, Odonate, and Seattle patients with advanced urothelial carcinoma: a phase 2 randomized clinical trial. Genetics; has served as an advisor/consultant to AstraZeneca, Lilly, Merck & Co., Nektar, JAMA Oncol. 7, 1536–1543 (2021). 34. Toledo, L. I. et al. A cell-based screen identifies ATR inhibitors with synthetic lethal Novartis, Pfizer, Genentech/Roche, Immunomedics, Bristol-Myers Squibb, Eisai, Nano- properties for cancer-associated mutations. Nat. Struct. Mol. Biol. 18,721–727 (2011). string, Puma, Sanofi, Celldex, Paxman, Puma, Silverback Therapeutics, G1 Therapeutics, 35. Murga, M. et al. Exploiting oncogene-induced replicative stress for the selective AbbVie, Anthenex, OncoPep, Outcomes4Me, Kyowa Kirin Pharmaceuticals, Daiichi- killing of Myc-driven tumors. Nat. Struct. Mol. Biol. 18, 1331–1335 (2011). Sankyo, Gilead, and Samsung Bioepsis Inc. G.I.S. has received research funding from Eli 36. Su, X. A. et al. RAD21 is a driver of chromosome 8 gain in Ewing sarcoma to Lilly, the healthcare business of EMD Serono, Billerica, MA USA, Merck & Co., and Sierra mitigate replication stress. Genes Dev. 35, 556–572 (2021). Oncology. He has served on advisory boards for Pfizer, Eli Lilly, G1 Therapeutics, Roche, 37. Williamson, C. T. et al. ATR inhibitors as a synthetic lethal therapy for tumours the healthcare business of EMD Serono, Billerica, MA USA, Sierra Oncology, Bicycle deficient in ARID1A. Nat. Commun. 7, 13837 (2016). Therapeutics, Fusion Pharmaceuticals, Cybrexa Therapeutics, Astex, Almac, Ipsen, Bayer, 38. Yap, T. A. et al. First-in-human trial of the oral ataxia telangiectasia and RAD3- Angiex, Daiichi Sankyo, Seattle Genetics, Boehringer Ingelheim, ImmunoMet, Asana, related (ATR) inhibitor BAY 1895344 in patients with advanced solid tumors. Artios, Atrin, Concarlo Holdings, Syros, Zentalis and CytomX Therapeutics. In addition, he Cancer Discov. 11,80–91 (2020). holds a patent entitled, “Dosage regimen for sapacitabine and seliciclib,” also issued to 39. Abkevich, V. et al. Patterns of genomic loss of heterozygosity predict homologous Cyclacel Pharmaceuticals, and a pending patent, entitled, “Compositions and Methods recombination repair defects in epithelial ovarian cancer. Br. J. Cancer 107, for Predicting Response and Resistance to CDK4/6 Inhibition,” together with Liam 1776–1782 (2012). Cornell. M.M.: personal fees from Amgen, grants and personal fees from Roche, grants 40. Pawlyn, C. et al. Loss of heterozygosity as a marker of homologous repair deficiency from AstraZeneca, grants and personal fees from GSK, personal fees and other from in multiple myeloma: a role for PARP inhibition? Leukemia 32,1561–1566 (2018). Novartis, other from Millenium, personal fees, non-financial support and other from 41. Telli, M. L. et al. Homologous recombination deficiency (HRD) score predicts Immunocore, personal fees and other from BMS and Eisai, other from Pfizer, personal response to platinum-containing neoadjuvant chemotherapy in patients with fees, non-financial support and other from MSD, personal fees and other from Rigontec triple-negative breast cancer. Clin. Cancer Res. 22, 3764–3773 (2016). (acquired by MSD), other from Regeneron, personal fees from BiolineRx, personal fees 42. Eisenhauer, E. A. et al. New response evaluation criteria in solid tumours: revised and other from Array Biopharma (now Pfizer), non-financial support and other from RECIST guideline (version 1.1). Eur. J. Cancer 45, 228–247 (2009). Replimune, personal fees from Kineta, and personal fees from Silicon Therapeutics, 43. MedDRA. Medical Dictionary for Regulatory Activities Version 21.0, https://admin. outside the submitted work. S.R.L.: personal fees from Eisai, Shionogi and Prosigna, and new.meddra.org/sites/default/files/guidance/file/dist_file_format_21_0_english. was previously employed by Pfizer, research funding from Pathios Therapeutics, pdf (2018). received travel, accommodation or expenses from Pfizer, Roche, Synthon and Piqur 44. NCI. Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0, https:// Therapeutics, cofounder and stock holding in Mitox Therapeutics. H.-T.A. has served as evs.nci.nih.gov/ftp1/CTCAE/CTCAE_4.03/Archive/CTCAE_4.0_2009-05-29_Quick an advisor/consultant for Bicycle Therapeutics, Biontech, Bayer, Beigene, Servier, Roche Reference_8.5x11.pdf (2009). and Guardant Health, and honoraria from Bicycle Therapeutics, Biontech, Bayer, 45. McLaren, W. et al. The Ensembl Variant Effect Predictor. Genome Biol. 17, 122 Beigene, Servier, Roche and Guardant Health. A.T.: AstraZeneca-Financial support to (2016). academic and hospital institutions for costs associated with academic study chair and 46. Clopper, C. J. & Pearson, E. S. The use of confidence or fiducial limits illustrated in local site costs for OlympiA trial/Travel expenses related to any trial related travel/ the case of the binomial. Biometrika 26, 404–413 (1934). Payments to Institution through Breast International Group for trial conduct in Olympia 47. Brookmeyer, R. & Crowley, J. A confidence interval for the median survival time. trial and through CRO’s for commercial PARP inhibitor trials AstraZeneca with royalties Biometrics 38,29–41 (1982). paid by Institute of Cancer Research with royalties paid for use of PARP inhibitors in DNA deficient cancers, licensee - AstraZeneca. Payments to Institute of Cancer Research and personally through ICR rewards to Inventors scheme. the healthcare business of ACKNOWLEDGEMENTS Merck KGaA, Darmstadt, Germany: local site trial support costs associated with clinical The authors would like to thank patients, investigators, co-investigators, and the study trial. Pfizer: personal fees/Advisory Board related to targeted therapies in DNA repair teams at each of the participating centers and at the healthcare business of Merck deficient cancers. Vertex: personal fees from/Advisory Board related to targeted KGaA, Darmstadt, Germany. The authors thank Vertex Pharmaceuticals for their therapies in DNA repair deficient. Artios: personal fees/Advisory Board related to involvement in the development of berzosertib (formerly M6620, VX-970). Giuseppe targeted therapies in DNA repair deficient cancers. Prime Oncology-Personal fees/ npj Breast Cancer (2022) 45 Published in partnership with the Breast Cancer Research Foundation M.L. Telli et al. Advisory Board related to targeted therapies in DNA repair deficient cancers. ADDITIONAL INFORMATION Medivation: financial support for research at ICR. Breast Cancer Now Charity: grant Supplementary information The online version contains supplementary material funded to study homologous recombination deficient breast and other cancers, BCN available at https://doi.org/10.1038/s41523-022-00406-0. receive payments through AstraZeneca related to PARP inhibitor patents. CRUK: grant funded to study homologous recombination deficient breast and other cancers, CRUK Correspondence and requests for materials should be addressed to Ruth Plummer. receive payments through AstraZeneca related to PARP inhibitor patents/personal fees/ honoraria associated with function as Deputy Chair and reviewer for CRUK Clinical Reprints and permission information is available at http://www.nature.com/ Research committee. Inbiomotion: personal fees/Scientific Ad Board function and stock reprints options. MD Anderson: personal fees/Moon shot Breast Cancer scientific advisory board Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims honoraria. Medscape Education honorarium from Merck & Co. educational grant: in published maps and institutional affiliations. personal fees/speaker for a video series. V.A. has received consulting fees from Daiichi Sankyo and Eisai and research grants from Genentech. E.D. was an employee and stockholder at AstraZeneca subsequent to involvement in this study. T.C.H. has received research funding from Takeda Oncology. R.W. has received research funding from Open Access This article is licensed under a Creative Commons Acerta Pharma and AstraZeneca; served on advisory boards for Puma Biotechnology, Attribution 4.0 International License, which permits use, sharing, Pfizer; and served on speakers’ bureau for Roche Diagnostics. J.F.-P. is an employee of adaptation, distribution and reproduction in any medium or format, as long as you give Ares Trading SA, Eysins, Switzerland, an affiliate of Merck KGaA, Darmstadt, Germany. T. appropriate credit to the original author(s) and the source, provide a link to the Creative Go. and T.Gr. are employees of the healthcare business of Merck KGaA, Darmstadt, Commons license, and indicate if changes were made. The images or other third party Germany. J.D. is an employee of EMD Serono, Billerica MA, USA. P.F.-M.: an employee of material in this article are included in the article’s Creative Commons license, unless EMD Serono, Billerica MA, USA. I.D.-P. was an employee of Ares Trading SA, Eysins, indicated otherwise in a credit line to the material. If material is not included in the Switzerland, an affiliate of Merck KGaA, Darmstadt, Germany, at the time of the study article’s Creative Commons license and your intended use is not permitted by statutory and is currently an employee of GlaxoSmithKline, Zug, Switzerland. R.P. has received regulation or exceeds the permitted use, you will need to obtain permission directly honoraria for attending advisory boards from Pierre Faber, Bayer, Octimet, Clovis from the copyright holder. To view a copy of this license, visit http://creativecommons. Oncology, Novartis, Karus Therapeutics, Biosceptre, BMS, Cybrexa, Ellipses, CV6 org/licenses/by/4.0/. Therapeutics, Astex Therapeutics and Sanofi Aventis. Fees for delivery of educational talks or chairing educational meetings by AstraZeneca, Novartis, Bayer, Tesaro and BMS. Funds to support attendance at conferences from BMS and MSD. © The Author(s) 2022 Published in partnership with the Breast Cancer Research Foundation npj Breast Cancer (2022) 45

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