Mary Lynne Hedley, PhD
A new drug application (NDA) to the FDA has been completed for niraparib as a maintenance treatment for women with recurrent platinum-sensitive ovarian, fallopian tube, or primary peritoneal cancer, according to the company developing the PARP1/2 inhibitor, Tesaro.
Patient demographics were well balanced between the arms for each cohort. In the germline BRCA
group, the median age was 57 years and 65.9% had an ECOG performance status (PS) of 0. In the placebo group, the median age was 58 years and 73.8% of patients had an ECOG PS of 0. Overall, 48.6% and 53.8% of patients had received ≥3 prior therapies, in the niraparib and placebo arms, respectively.
Across both cohorts, the majority of patients had stage III cancer (68.8% to 74.1%). Approximately half of patients had achieved a complete response to prior platinum-based therapy and a quarter had received prior bevacizumab. In the non-BRCA
-mutant arm, 33.8% and 32.8% of patients had received ≥3 prior therapies.
In the germline BRCA
mutation group, the chemotherapy-free interval was 22.8 months with niraparib compared with 9.4 months for placebo (HR, 0.26; 95% CI, 0.17-0.41; P
<.001). The median time to subsequent therapy was 21 months with niraparib versus 8.4 months with placebo (HR, 0.31; 95% CI, 0.21-0.48).
The median time to progression or death during the first subsequent therapy following the study (PFS2) was 25.8 months for those who received maintenance niraparib versus 19.5 months for placebo (HR, 0.48; 95% CI, 0.28-0.82; P
Findings for overall survival were not yet mature (fewer than 20% of events). At the time of the analysis, niraparib had reduced the risk of death by 27% versus placebo, although this finding was not statistically significant (HR, 0.73; 95% CI, 0.480-1.125; P
In patients with HRD-positive, BRCA
wild-type tumors, median PFS was 9.3 versus 3.7 months for niraparib and placebo, respectively (HR, 0.38; 95% CI, 0.23-0.63; P
<.001). In those with HRD-positive, somatic BRCA-mutated tumors, the median PFS was 20.9 months with niraparib versus 11.0 months for placebo (HR, 0.27; 95% CI, 0.08-0.90; P
= .02). In patients with HRD-negative, non-germline BRCA-mutated tumors, median PFS was 6.9 versus 3.8 months for niraparib and placebo, respectively (HR, 0.58; 95% CI, 0.36-0.92; P
In those with non-germline BRCA
mutations regardless of HRD status, the median chemotherapy-free interval was 12.7 versus 8.6 months for niraparib and placebo, respectively (HR, 0.50; 95% CI, 0.37-0.67; P
<.001). The median time to subsequent therapy was 11.8 versus 7.2 months (HR, 0.55; 95% CI, 0.41-0.72; P
<.001) and the median PFS2 was 18.6 and 15.6 months for the niraparib and placebo arms, respectively (HR, 0.69; 95% CI, 0.49-0.96; P
Across cohorts, 14.7% of 367 niraparib-treated patients discontinued therapy due to an adverse event (AE) compared with 2.2% of the 179 patients in the placebo arm. There were no treatment-related deaths in the study. In the follow-up period, 1 patient in the niraparib arm and 2 in the placebo group died of myelodysplastic syndrome or acute myeloid leukemia. One of these deaths in each arm was deemed to be treatment related.
The most common all-grade AEs for niraparib versus placebo, respectively, were nausea (73.6% vs 35.2%, respectively), thrombocytopenia (61.3% vs 5.6%), fatigue (59.4% vs 41.3%), anemia (50.1% vs 6.7%), constipation (39.8% vs 20.1%), vomiting (34.3% vs 16.2%), and neutropenia (30.2% vs 6.1%).
The most common grade 3/4 AEs in the niraparib arm were hematologic, and included thrombocytopenia (33.8%), anemia (25.3%), and neutropenia (19.6%). The most common non-hematologic AEs were hypertension (8.2%), fatigue (8.2%), and nausea (3%). A majority of hematologic AEs were experienced in the first 3 cycles.
Tesaro initiated a rolling submission of data from the NOVA trial for a new drug application in September 2016, after receiving a fast track designation from the FDA.
- Mirza MR, Monk BJ, Oza A, et al. A randomized, double-blind phase 3 trial of maintenance therapy with niraparib vs placebo in patients with platinum-sensitive recurrent ovarian cancer (ENGOT-OV16/NOVA trial). Presented at: 2016 ESMO Congress; October 7-11, 2016; Copenhagen, Denmark. Abstract LBA3_PR.
- Mirza MR, Monk B, Herrstedt J, et al. Niraparib maintenance therapy in platinum-sensitive recurrent ovarian cancer [published online October 8, 2016]. N Engl J Med. DOI: 10.1056/NEJMoa1611310.