China-based Zai Lab Limited (NASDAQ: ZLAB, HKG: 9688) is set to present two oral presentations highlighting the ad hoc interim overall survival (OS) study results for the poly (ADP-ribose) polymerase inhibitor (PARPi) Zejula (niraparib). The presentations will focus on the NORA Phase III study and a post hoc analysis from the Phase III PRIME trial, assessing niraparib as a maintenance therapy. These presentations will be given at the upcoming European Society for Medical Oncology (ESMO) Gynaecological Cancers Congress on February 23-24, 2023.
NORA Phase III Study Results
An ad hoc interim OS data analysis of the Phase III NORA trial showed that niraparib maintenance therapy with an individualized starting dose (ISD) provided a favorable OS trend compared to a placebo in Chinese patients with platinum-sensitive recurrent ovarian cancer (PSROC), regardless of biomarker status. The median overall survival (mOS) in the niraparib-treated group was numerically higher at 46.3 months compared to 43.4 months in the placebo group [HR=0.82; 95% CI, 0.56-1.21]. In the gBRCA mutation subgroup, the mOS was not reached for patients receiving niraparib versus 47.6 months for the placebo group [HR=0.76; 95% CI, 0.40-1.46]. In the non-gBRCA mutation subgroup, the mOS was 43.1 months for the niraparib-treated group versus 38.4 months for the placebo group [HR=0.86; 95% CI, 0.53-1.38]. This new data analysis explores the treatment effect of niraparib versus placebo on OS, adjusted for subsequent PARPi use in the placebo group.
PRIME Phase III Trial Post Hoc Analysis
Post hoc analysis from the randomized, double-blind, placebo-controlled Phase III PRIME trial showed that niraparib was associated with improved progression-free survival (PFS) regardless of surgical timing and residual disease status compared with placebo in patients with newly diagnosed advanced ovarian cancer in China. The median PFS for the primary debulking surgery (PDS) group was not reached in patients receiving niraparib versus 12 months for the placebo group [HR 0.63; 95% CI 0.42–0.94]. The median PFS in the interval debulking surgery (IDS) group was 22.3 months for patients receiving niraparib versus 5.6 months for the placebo group [HR = 0.32; 95% CI 0.21-0.48].
Zai Lab’s Acquisition and Market Approvals
Zai Lab acquired the Greater China development and commercialization rights to Zejula in an October 2016 deal from Tesaro Inc., which is now owned by GlaxoSmithKline. Zejula gained market approvals in Hong Kong and Macau in October 2018 and June 2019, respectively, and was launched in China in January 2020 for the first indication as a maintenance therapy in recurrent ovarian cancer in patients responsive to chemotherapy. In September 2020, the drug obtained supplementary new drug application (sNDA) approvals in China for use as maintenance treatment of adult patients with advanced epithelial ovarian cancer, fallopian tube cancer, primary peritoneal cancer, or those partially responsive to first-line platinum-containing chemotherapy. Finally, the drug entered the National Reimbursement Drug List (NRDL) in late 2020.
Strategic Implications
The presentation of these study results at the ESMO Congress highlights the ongoing commitment of Zai Lab to advancing the understanding and treatment of ovarian cancer. By presenting the OS and PFS data from the NORA and PRIME trials, Zai Lab aims to further demonstrate the potential benefits of Zejula in improving patient outcomes. These efforts are expected to enhance Zai Lab’s position in the oncology market and contribute to the broader goal of improving cancer care.-Fineline Info & Tech
