Click Here to
Subscribe
Breaking
News, Updates,
& More
Stay Up
to Date

Niraparib Efficacy in Advanced Ovarian Cancer Extends to All Biomarker Subgroups

Web Exclusives - Ovarian Cancer

Niraparib monotherapy may represent a new opportunity after first-line platinum-based chemotherapy in the treatment of advanced ovarian cancer, based on an updated analysis of the phase 3 PRIMA study presented at the 2020 Society of Gynecologic Oncology Annual Meeting on Women’s Cancer.

The exploratory analysis showed that treatment with niraparib (Zejula) improved progression-free survival (PFS) in patients regardless of their biomarker status.

In the analysis, patients who received niraparib in all biomarker groups had a statistically significant and clinically meaningful PFS benefit, with an overall 38% reduction in the risk for a progression event (hazard ratio [HR], 0.62; P <.0001). In patients with homologous recombination deficiency, as reported previously, the risk for cancer recurrence or death was reduced by 57% in patients who received niraparib compared with placebo (P <.0001).

Niraparib previously demonstrated an improvement in PFS in patients with newly diagnosed advanced ovarian cancer after first-line platinum-based chemotherapy, including patients at the highest risk for relapse. In the exploratory analysis of PRIMA presented, Bradley J. Monk, MD, FACOG, FACS, Gynecologic Oncologist, Arizona Oncology (US Oncology Network), Phoenix, and colleagues evaluated the efficacy of niraparib according to biomarker subgroups.

The PRIMA clinical trial enrolled 733 patients with newly diagnosed advanced ovarian, primary peritoneal, or fallopian tube cancer with a complete or partial response to first-line platinum-based chemotherapy. They were randomized in a 2:1 ratio to niraparib or placebo once daily.

After the trial had enrolled nearly two-thirds of patients, niraparib dosing was individualized for the remaining patients enrolled.

Of the 733 patients randomized, 373 (51%) had homologous recombination deficiency and 249 (34%) had homologous recombination proficiency.

In the subset of patients with BRCA mutations, niraparib reduced the risk for progression by 60% (HR, 0.40; P <.0001), and in those with BRCA wild-type, the reduction in risk was 50% (HR, 0.50; P = .0064).

Niraparib efficacy for PFS was similar in patients with BRCA1 mutations (HR, 0.39; 95% confidence interval [CI], 0.23-0.66) and BRCA2 mutations (HR, 0.35; 95% CI, 0.15-0.84).

The rate of dose modifications and the safety profile were similar to data reported in earlier trials of niraparib. The researchers reported that no new safety signals were identified in the current trial.

“I think all of us recognize that BRCA1 mutations are about twice as common as BRCA2. We realize that BRCA1 is more pathogenic, meaning the risk of breast and ovarian cancer is higher, and we also realize that BRCA1 patients are harder to treat with a PARP inhibitor,” said Dr Monk. “In this hypothesis-generating exploratory analysis, there was a consistent treatment effect in the BRCA1 and BRCA2 patients. This is an important new piece of information.”

In addition to the significant benefit on PFS in the homologous recombination-deficient subgroup, niraparib also provided a 32% reduction in the risk for a PFS event (HR, 0.68; P = .0203) in the homologous recombination-proficient subgroup.

After dosing of niraparib was individualized, the rate of grade ≥3 thrombocytopenia in the niraparib arm decreased from 36% to 15%, said Dr Monk. “So, there’s an opportunity here to individualize the dose based on weight and baseline platelet count. We have not shown the impact of outcomes for this, but stay tuned.”

Related Items
Telehealth Coverage Expanded During the COVID-19 Pandemic
Web Exclusives published on November 19, 2020 in Ovarian Cancer
Trabectedin Added to Pegylated Doxorubicin May Be Viable Treatment for Recurrent Ovarian Cancer But Platinum Remains Standard of Care
Web Exclusives published on November 19, 2020 in Ovarian Cancer
NORA Clinical Trial Confirms Efficacy of Individualized Niraparib Starting Dose to Treat Platinum-Sensitive Ovarian Cancer
Web Exclusives published on November 19, 2020 in Ovarian Cancer
Increased Uptake of Neoadjuvant Chemotherapy Does Not Explain Trend Toward Improved Survival in Advanced Ovarian Cancer
Web Exclusives published on November 19, 2020 in Ovarian Cancer
Platinum-Based Chemotherapy Following Progression on PARP Inhibitor Maintenance Yields Greatest Benefit in Advanced Ovarian Cancer with Platinum-Free Interval >12 Months
Web Exclusives published on November 19, 2020 in Ovarian Cancer
ASCO Guidelines Support PARP Inhibitor Use in Maintenance and Recurrent Setting of Advanced Ovarian Cancer
Web Exclusives published on October 13, 2020 in Ovarian Cancer
Olaparib/Bevacizumab as First-Line Maintenance Reduces Risk for Progression or Death in Patients with Advanced Ovarian Cancer
Web Exclusives published on October 13, 2020 in Ovarian Cancer
Online Delivery of Genetic Services: No Increase in Cancer Risk Distress versus Telephone Counseling
Web Exclusives published on October 13, 2020 in Ovarian Cancer
Phase 2 OVARIO Update: Promising Survival Rates in Patients with Advanced Ovarian Cancer Treated with Niraparib plus Bevacizumab Maintenance
Web Exclusives published on September 15, 2020 in Ovarian Cancer
No Difference in PFS Between Platinum-Based Chemotherapy and Olaparib in Women with Platinum-Sensitive Ovarian Cancer
Web Exclusives published on September 15, 2020 in Ovarian Cancer
Last modified: October 13, 2020