Lainie Martin

C ombination A TR (ceralasertib) and P A R P (olaparib) I nhibitor (CAPRI) Trial in Acquired PARP Inhibitor–Resistant Homologous Recombination–Deficient Ovarian Cancer

Abstract Purpose: Addition of ataxia telangiectasia and Rad3-related kinase inhibitors (ATRi) to PARP inhibitors (PARPi) overcomes PARPi resistance in high-grade serous ovarian cancer (HGSOC) cell and mouse models. We present the results of an investigator-initiated study of combination PARPi (olaparib) and ATRi (ceralasertib) in patients with acquired PARPi-resistant HGSOC. Patients and Methods: Eligible patients had recurrent, platinum-sensitive BRCA1/2 mutated or homologous recombination (HR)–deficient (HRD) HGSOC and clinically benefited from PARPi (response by imaging/CA-125 or duration of maintenance therapy; > 12 months first-line or > 6 months ≥ second-line) before progression. No intervening chemotherapy was permitted. Patients received olaparib 300 mg twice daily and ceralasertib 160 mg daily on days 1 to 7 of a 28-day cycle. Primary objectives were safety and objective response rate (ORR). Results: Thirteen patients enrolled were evaluable for safety and 12 for efficacy; 62% (n = 8) had germline BRCA1/2 mutations, 23% (n = 3) somatic BRCA1/2 mutations, and 15% (n = 2) tumors with positive HRD assay. Prior PARPi indication was treatment for recurrence (54%, n = 7), second-line maintenance (38%, n = 5) and first-line treatment with carboplatin/paclitaxel (8%, n = 1). There were 6 partial responses yielding an ORR of 50% (95% confidence interval, 0.15–0.72). Median treatment duration was 8 cycles (range 4–23+). Grade (G) 3/4 toxicities were 38% (n = 5); 15% (n = 2) G3 anemia, 23% (n = 3) G3 thrombocytopenia, 8% (n = 1) G4 neutropenia. Four patients required dose reductions. No patient discontinued treatment due to toxicity. Conclusions: Combination olaparib and ceralasertib is tolerable and shows activity in HR-deficient platinum-sensitive recurrent HGSOC that benefited and then progressed with PARPi as the penultimate regimen. These data suggest that ceralasertib resensitizes PARPi-resistant HGSOCs to olaparib, warranting further investigation.

Rucaparib maintenance for newly diagnosed advanced ovarian cancer: interim overall survival, progression-free survival, and safety at 5 years of follow-up from the phase III ATHENA-MONO/GOG-3020/ENGOT-ov45 study

We report the long-term efficacy and safety from the multicenter, randomized, double-blind, placebo-controlled, phase III ATHENA-MONO/GOG-3020/ENGOT-ov45 (NCT03522246) study of first-line rucaparib maintenance for advanced ovarian cancer. Patients were randomized 4 : 1 to oral rucaparib + intravenous (i.v.) placebo or oral + i.v. placebo. Stratification factors were homologous recombination deficiency (HRD; BRCA mutation and loss of heterozygosity status) classification, residual disease post-chemotherapy, and surgical timing. The primary endpoint was investigator-assessed progression-free survival (invPFS) in HRD and intent-to-treat (ITT) populations. Overall survival (OS) and safety were secondary endpoints. Second event of progression (PFS2) and time to first subsequent treatment (TFST) were exploratory. Interim OS and final safety analyses data cut-off was 9 March 2023. Updated invPFS, PFS2, and TFST analyses data cut-off was 5 May 2025. Median invPFS follow-up was ∼59 months for both rucaparib (HRD, n = 185; ITT, n = 427) and placebo (HRD, n = 49; ITT, n = 111). invPFS was significantly longer with rucaparib versus placebo in the HRD [31.4 versus 12.0 months; hazard ratio (HR) 0.52, 95% confidence interval (CI) 0.35-0.76] and ITT (20.2 versus 9.2 months; HR 0.53, 95% CI 0.42-0.69) populations. Interim OS was immature (OS maturity: ITT 35%) with the median (95% CI) OS not reached with rucaparib and 46.2 (34.6-not reached) months with placebo for the ITT population (HR 0.83, 95% CI 0.58-1.17). ITT TFST (median 23.6 versus 12.1 months) and PFS2 (35.1 versus 26.9 months) were longer with rucaparib versus placebo. Overall, 34.6% of patients receiving rucaparib completed the 24-month treatment cap versus 17.3% receiving placebo. As of 5 May 2025, 40.0% of patients on rucaparib were still on study and in long-term follow-up. Safety remained consistent with the primary analysis. Rucaparib monotherapy provides significant and durable long-term benefit as first-line maintenance for patients with advanced ovarian cancer with and without HRD.