287MO - Real-world experience with maintenance PARP inhibitor plus minus bevacizumab in newly diagnosed advanced ovarian cancer with germline BRCA mutations or homologous recombination deficiency (HRD) positive

Background

Real world Indian data with maintenance Poly ADP Ribose Polymerase 1 Inhibitors (PARPi) in newly diagnosed advanced ovarian cancer (AOC) are lacking. The purpose of this study was to evaluate optimal dosing, safety and efficacy of olaparib or rucaparib maintenance plus minus bevacizumab in germline BRCA mutations or HRD-positive AOC patients.

Methods

This was a retrospective study from Tata Medical Center, Kolkata, West Bengal, India; included patients with stage III & IV (AJCC 7th) AOC between 2020- 2023. All data captured from electronic medical records of hospital up till June 2023. Either standard dose or reduced dose of tablet olaparib (450mg/day orally) or rucaparib (600mg/day orally) plus minus injection bevacizumab (7.5 mg/kg IV q 3weekly) was offered as a front-line maintenance therapy after completion of surgery and platinum based chemotherapy without any residual disease.

Results

Out of 89 screened patients, 41 received therapy with a median age at diagnosis 57 years (range 41-74). 98% had high grade serous histology with 61% stage III and 39% stage IV diseases. 28(68%) patients had germline BRCA mutations and 13(32%) HRD-positive (high genomic scar score). 34(82%) patients received maintenance bevacizumab up to one year along with PARPi. The duration of exposure of PARPi ranged from 2-24 months and 63% patients started with reduced dose. Dose reductions due to adverse effects (AEs) seen in 42%. With a median follow up of 32 months (95% CI 22.04-41.95); two years predicted progression free survival (PFS) of the entire cohort was 84%, no difference in PFS between standard dose and reduced dose group (30 vs 35 months; log rank p=0.67). There was no significant difference in PFS among olaparib and rucaparib (NR vs 35 months; log rank p=0.20). The most common ≥ grade III AEs (CTCAE V.5) were anemia (24%), thrombocytopenia (7%), fatigue (22%), diarrhea (2%) and transamnitis (5%).

Conclusions

We found that lower doses of PARPi were equally efficacious with good tolerance in comparison with standard dose and can be offered as first-line maintenance therapy in AOC patients with germline BRCA mutation or HRD positive in a resource-limited setting.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.