Positive Phase 3 Data for PARP Inhibitor Niraparib in Ovarian Cancer

By Reuters Staff

March 28, 2022

NEW YORK (Reuters Health) - Maintenance therapy with the PARP inhibitor niraparib provided statistically significant and clinically meaningful improvement in progression-free survival (PFS), regardless of biomarker status, in women with newly diagnosed advanced epithelial ovarian, fallopian tube or primary peritoneal cancer enrolled in the PRIME trial.

"The PRIME data continue to support niraparib monotherapy as the standard of care after first-line platinum-based chemotherapy regardless of biomarker status," Dr. Alan Sandler, president and head of global development, oncology at Zai Lab, the study's funder, said in a news release.

The phase-3 study was presented at the Society of Gynecologic Oncology annual meeting.

The study enrolled 384 women with advanced ovarian cancer who achieved complete or partial response to first-line platinum-based chemotherapy and received primary or interval cytoreductive surgery, irrespective of residual-disease status after surgery.

The women were randomly allocated to maintenance therapy with dose-individualized niraparib or placebo. The overall PFS median follow-up period was 27.5 months.

During the PRIME study, median PFS was significantly longer in the niraparib group than the placebo group (24.8 months vs. 8.3 months; hazard ratio, 0.45; P<0.001). [ABSTRACT HAS DIFF NO BUT ASSUME PR IS RIGHT]

In women with germline BRCA mutations, median PFS was not reached with niraparib versus 10.8 months with placebo (HR, 0.40).

In women with non-germline BRCA mutations, median PFS was 19.3 months with niraparib compared to 8.3 months with placebo (HR, 0.48).

While overall survival data are not mature, there was a trend in favor of niraparib at data cutoff.

No new safety signals emerged. The most common treatment-emergent adverse events were hematological and gastrointestinal in nature. One case each of acute myeloid leukemia and myelodysplastic syndrome were reported in the niraparib group.

"I believe the data of the PRIME study will have a significant impact on the clinical practice in the first-line treatment of ovarian cancer in China and beyond, as the individualized starting dose regimen has demonstrated an improved efficacy and safety profile," Dr. Lingying Wu of the Chinese Academy of Medical Sciences and Peking Union Medical College, one of the paper's authors, said in the news release.

The study was funded by Zai Lab (Shanghai) Co Ltd and partially supported by the National Major Scientific and Technological Special Project for 'Significant New Drugs in Development' in 2020, China.

SOURCE: https://bit.ly/3ts4qES Society of Gynecologic Oncology (SGO) Annual Meeting, Phoenix, Arizona, March 18-21, 2022.