OVARIO, A Phase 2 Study of Niraparib + Bevacizumab in Advanced Ovarian Cancer Following Front-Line Platinum-Based Chemotherapy with Bevacizumab: Updated Analysis (039)

• Published in: Gynecologic oncology 2022-08, Vol.166, p.S27-S28
• Main Authors: Hardesty, Melissa, MD, MPH, Krivak, Thomas, MD, Wright, Gail, MD, Hamilton, Erika, MD, Fleming, Evelyn, MD, Belotte, Jimmy, MD, PhD, Keeton, Erika, PhD, Wang, Ping, Clements, Aine, MD, Gray, Heidi, Konecny, Gottfried, MD, Moore, Richard, MD, Richardson, Debra, MD
• Format: Article
• Language: English
• Subjects: Hematology, Oncology, and Palliative Medicine; Obstetrics and Gynecology
• ISSN: 0090-8258
• DOI: 10.1016/S0090-8258(22)01258-6

Objectives: Niraparib is a PARP inhibitor (PARPi) approved for maintenance treatment of advanced (first-line [1L]) or recurrent ovarian cancer (OC) in patients (pts) who responded to platinum-based chemotherapy (CT). Niraparib monotherapy improved progression-free survival (PFS) in all pts with newly diagnosed advanced OC versus placebo in the PRIMA trial. Bevacizumab (bev), a vascular endothelial growth factor-A inhibitor, is hypothesized to sensitize tumors to PARPis by inducing hypoxia and altering DNA damage repair pathways. Niraparib + bev improved PFS versus niraparib alone in pts with high-grade serous or endometrioid platinum-sensitive recurrent OC. This phase II study (OVARIO; NCT03326193) aimed to evaluate niraparib + bev maintenance treatment in advanced OC after response to 1L platinum-based CT + bev. Patient demographics, safety data, and 18 - month PFS rate have been previously presented. We reported updated efficacy and patient-reported outcomes. Methods: Eligible pts had newly diagnosed high-grade serous or endometrioid stage IIIB-IV epithelial ovarian, fallopian tube, or primary peritoneal cancer with a complete response, partial response, or no evidence of disease after 1L platinum-based CT + bev. Pts receiving neoadjuvant CT or primary debulking surgery were eligible. Homologous recombination (HR) tissue testing was completed at enrollment. Pts received niraparib 200 or 300 mg QD (based on body weight/platelet count) + bev 15 mg/kg Q3W. Niraparib was started within 12 weeks of completing 1L treatment and continued for three years or until progression/unacceptable toxicity; bev was given for ≤15 months, including time during 1L CT. The primary endpoint was the 18 - month PFS rate. Secondary endpoints included PFS, overall survival (OS), safety, tolerability, and change from baseline in the Functional Assessment of Cancer Therapy–Ovarian Symptoms Index (FOSI) score. Results: This analysis included 105 pts. At the data cut-off (June 16, 2021), the median duration of follow-up was 27.6 months (95% CI: 25.5-27.7). Median PFS (mPFS) was 19.6 months (95% CI: 16.5-25.1) in the overall population. In the HR-deficient (HRd) population ( n=49), mPFS was 28.3 months (95% CI: 19.9-non-estimable [NE]); mPFS was 28.3 months (95% CI: 12.1-NE) in the HRd/ BRCA-wildtype population ( n=16) and was NE in the HRd/ BRCA-mutant population ( n=29). In the HR-proficient population ( n=38), mPFS was 14.2 months (95% CI: 8.6-16.8). The 24-month PFS rates will be p