Dr. Mirza on Efficacy of Niraparib/Bevacizumab Combo in Recurrent Ovarian Cancer

Mansoor Raza Mirza, MD, chief oncologist, Department of Oncology in Rigshospitalet, Copenhagen University Hospital, discusses results from the phase II NSGO-AVANOVA2/ENGOT-OV24 trial comparing niraparib (Zejula) with niraparib plus bevacizumab (Avastin) in patients with recurrent platinum-sensitive ovarian cancer.

In the randomized phase II trial, patients were randomized to receive either niraparib or niraparib plus bevacizumab. Progression-free survival (PFS) served as the primary endpoint of the trial. The goal is for patients to remain on the treatment until disease progression, explains Mirza.

Results from AVANOVA show that the doublet therapy composed of niraparib and bevacizumab significantly improved PFS compared with niraparib alone in the intent-to-treat population (median 11.9 months versus 5.5 months; HR adjusted for stratification factors, 0.35; 95% CI, 0.21-0.57; P <.001).

Furthermore, results from a pre-planned exploratory subgroup analysis showed similar efficacy between the arms in patients with homologous recombination deficiency (HRD)-positive (n = 54; HR, 0.36; 95% CI, 0.18-0.69) and -negative tumors (n = 43; HR, 0.47; 95% CI, 0.24-0.95), according to Mirza. In the patient population with BRCA mutations, the hazard ratio was 0.49, says Mirza, but there were only 33 patients with those mutations. Strong efficacy was observed in patients with BCRA wild-type disease, he adds.

The safety profile of the combination was as expected. Treatment with niraparib plus bevacizumab led to more events of hypertension, which is a known toxicity associated with bevacizumab. Mirza concludes that overall, both treatment regimens were well-tolerated. Only 6 patients who received the doublet and 5 patients who received the single agent stopped treatment due to toxicity.

Based on these results, a phase III trial called ENGOT-OV42/NSCO-AVATAR, which will compare the combination with standard of care, is set to begin by the end of 2019.