PARP Inhibitor Pamiparib Under Review in China to Treat Advanced Ovarian Cancer

PARP Inhibitor Pamiparib Under Review in China to Treat Advanced Ovarian Cancer

China’s regulatory agency has agreed to consider a request that pamiparib, BeiGene‘s investigational PARP inhibitor, be approved to treat people with advanced ovarian cancers after at least two prior lines of chemotherapy.

The company’s new drug application (NDA), submitted to the Center for Drug Evaluation of the Chinese National Medical Products Administration, is specifically for patients with ovarian, fallopian tube, or primary peritoneal cancer whose tumors have, or are thought to have, mutations in BRCA, a DNA repair gene.

“This is our first NDA filing for pamiparib, which was discovered by BeiGene and is being developed as both a monotherapy and in combination with other agents, including our own anti-PD1 antibody, tislelizumab,” Yong Ben, MD, chief medical officer of Immuno-Oncology at BeiGene, said in a press release.

“For patients in China with advanced ovarian cancer, we are hopeful that pamiparib can offer a new treatment option,” Ben added.

Pamiparib (BGB-290) is an investigational inhibitor of PARP1 and PARP2, two PARP enzymes that are involved in DNA repair. By blocking the activity of these two enzymes, pamiparib aims to prevent cancer cells from repairing their DNA, eventually killing them.

PARP inhibitors like pamiparib tend to be more effective in patients whose cancer cells carry mutations in genes that also affect their ability to repair DNA.

The application is supported by data from a Phase 1/2 trial (NCT03333915), investigating the safety, tolerability, and anti-tumor activity of increasing doses of pamiparib in patients in China with advanced ovarian, fallopian, primary peritoneal, or triple negative breast cancer.

During its first phase, which aimed to determine the optimal therapy dose for Phase 2, patients enrolled were given pamiparib capsules at 20, 40, or 60 mg doses twice daily.

Study data, presented at the 2018 American Association for Cancer Research (AACR) Annual Meeting, showed pamiparib was safe and well-tolerated across all tested doses, and established as optimal the 60 mg twice-daily dosing schedule.

An analysis of nine Phase 1 patients with high-grade non-mucinous ovarian cancer also showed disease stabilization in six women and partial responses in two others following treatment with pamiparib.

Phase 2 enrolled 113 women with high-grade epithelial ovarian cancer or high-grade endometrioid epithelial cancer; all had  mutations in BRCA1 or BRCA2 and at least two prior lines of standard chemotherapy.

Participants here were treated with pamiparib at 60 mg twice a day. This study phase’s main goal is to assess the percentage of patients responding to treatment, as well as the type of responses achieved.

Data from this second part will be presented at a future medical conference, Beigene said in the release.

“We look forward to presenting the clinical data … and additional results, including Phase 3 data, in the upcoming months,” Ben said.