Niraparib Shows Efficacy in Platinum-Sensitive Ovarian Cancer

Niraparib (Zejula) demonstrated progression-free survival (PFS) benefit for patients with platinum-sensitive ovarian cancer, according to a press release from Zai Lab Limited.¹ The results of the trial investigating niraparib will be presented at an upcoming medical conference.

The phase 3 PRIME study (NCT03705156) of niraparib met its primary end point of statistically significant PFS with a tolerable safety profile in a trial of 384 Chinese patients who were responsive to platinum-based chemotherapy. Niraparib is an oral PARP inhibitor approved for patients with advanced and relapsed epithelial ovarian cancer.

On April 29, 2020, niraparib was approved by the FDA for frontline maintenance in patients with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer who experience complete or partial response to platinum-based chemotherapy.² The approval came after the phase 3 PRIMA trial (NCT02655016) showed a PFS benefit of 13.8 months compared with 8.2 for those who received placebo (HR, 0.62; 95% CI, 0.50-0.76; P < .001).³

“The PRIME clinical data in Chinese patients confirmed the clinical profile of Zejula and were consistent with the results seen in the global PRIMA study,” Alan Sandler, MD, president and head of Global Development, Oncology at Zai Lab, said in a statement.¹ “Importantly, the PRIME study further underscores the status of Zejula as the first and only PARP inhibitor approved globally, including in China, as monotherapy for all-comer patients in the first-line maintenance treatment settings.”

Patients in the PRIME trial were randomized into the experimental arm or placebo arm at a 2:1 ratio. Those in the experimental arm received 200 mg or 300 mg of niraparib orally based on the patient’s body weight. The primary end point of PFS for up to 35 months was determined by Independent Central Imaging Review according to RECIST version 1.1. Secondary end points were chemotherapy-free interval, time to the next anticancer treatment, and overall survival.

In September 2020, Zai Lab’s phase 3 NORA trial (NCT03705156) of niraparib demonstrated PFS benefit and improved safety profile in patients with recurrent platinum-sensitive ovarian cancer, with results published in Annals of Oncology.⁴ In the NORA trial, median PFS for patients receiving niraparib was 18.3 months (95% CI, 10.9–not evaluable) compared with 5.4 months (95% CI, 3.7-5.7 [HR: 0.32; 95% CI, 0.23-0.45; P < 0.0001). Treatment-emergency adverse events of grade 3 or higher were reported in 50.8% of patients versus 19.3% of those who received a placebo.

“The PRIME study is the only study conducted in China that has demonstrated that a PARP inhibitor significantly improved PFS when given as monotherapy maintenance therapy in all Chinese patients with newly diagnosed ovarian cancer, regardless of biomarker status.” Lingying Wu, MD, director of the Department of Gynecologic Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, said in a press release.

“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 safety profile,” Wu stated.

_References:

_{1. Zai Lab announces positive topline results from phase 3 PRIME study of Zejula® (niraparib) as first-line monotherapy maintenance treatment in Chinese women with platinum-responsive advanced ovarian cancer. Zai Lab. Published November 30, 2021. Accessed November 30, 2021. https://bit.ly/3I4Coof}

_{2. FDA approves niraparib for first-line maintenance of advanced ovarian cancer. FDA. Published April 29, 2020. Accessed November 30, 2021. https://bit.ly/3pcU2O2}

_{3. González-Martín A, Pothuri B, Vergote I, et al. Niraparib in patients with newly diagnosed advanced ovarian cancer. N Engl J Med. 2019;381(25):2391-2402. doi:10.1056/NEJMoa1910962}

_{4. Wu XH, Zhu JQ, Yin RT, et al. Niraparib maintenance therapy in patients with platinum-sensitive recurrent ovarian cancer using an individualized starting dose (NORA): a randomized, double-blind, placebo-controlled phase III trial. Ann Oncol. 2021;32(4):512-521. doi:10.1016/j.annonc.2020.12.018}