765P - SABRINA study: A phase II study of senaparib monotherapy for patients (pts) with BRCA1/2 mutated recurrent platinum-sensitive ovarian cancer (PSOC)

Background

Senaparib (IMP4297) is a novel, high potency PARP inhibitor and showed promising antitumor activity for advanced ovarian cancer in phase I studies. This open label, multicenter, single arm, phase II study aimed to evaluate the efficacy and safety of senaparib in pts with BRCA mutated recurrent PSOC.

Methods

Pts with germline and/or somatic BRCA mutated recurrent PSOC who had previously received ≥ 2 lines of platinum-based chemotherapy were enrolled. Senaparib 100 mg was administered orally once daily. The primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR) and secondary endpoints included investigator (INV)-assessed ORR, progressive free survival (PFS), duration of response (DOR), overall survival (OS) and safety.

Results

As of 30 Jan 2023, 93 pts were enrolled. Treatment was still ongoing in 26 pts. Median age was 55 y (range 31–77), and 59%/41% pts were partially/fully platinum sensitive, with a median 2 prior systemic therapies (range 2-7). After a median follow up of 15.7 months, efficacy was assessed in 91 pts who received treatment of senaparib and ≥ 1 tumor evaluated and met the criteria for the response evaluable set. The INV-assessed confirmed ORR was 59.3% (95% CI, 48.4-69.2) and disease control rate (DCR) was 93.4% (95% CI, 86.2-97.5). Median DOR was 10.3 mo (95% CI, 8.2-12.0). Median PFS was 11.1 mo (95% CI, 8.3-13.8). Median OS was 31.6 mo (95% CI, 25.2-not reached) with 90% and 69% of 1 year and 2 years survival rate. IRC had not finished the assessment. 4% of pts discontinued treatment. The most common (≥ 20%) TEAEs were anemia (71%), decreased white blood cell count (55%), decreased platelet count (54%), decreased neutrophil count (50%), and nausea (28%). Grade ≥3 TEAEs in ≥5% of pts were anemia (42%), decreased neutrophil count (17%), decreased white blood cell count (16%), and decreased platelet count (16%). 2 pts reported fatal TEAEs, both of which were judged not related to treatment.

Conclusions

Senaparib demonstrated clinically meaningful antitumor activity and manageable safety profile in BRCA1/2 mutated recurrent PSOC. The OS was immature but seemed to be improved.

Clinical trial identification

NCT04089189.

Editorial acknowledgement

Legal entity responsible for the study

Impact Therapeutics, Inc.

Funding

Impact Therapeutics, Inc.

Disclosure

All authors have declared no conflicts of interest.