NEW YORK – Janssen Pharmaceuticals on Thursday submitted a marketing authorization application to the European Medicines Agency (EMA) seeking approval of its PARP inhibitor Zejula (niraparib) in combination with abiraterone acetate and prednisolone for metastatic castration-resistant prostate cancer patients who harbor homologous recombination repair (HRR) gene alterations.
The submission is based on data from the Phase III MAGNITUDE study comparing Zejula plus abiraterone acetate and prednisolone against placebo plus abiraterone acetate and prednisolone. The study enrolled metastatic castration-resistant prostate cancer patients with alterations in a range of genes involved in HRR including ATM, BRCA1, BRCA2, BRIP1, CDK12, CHEK2, FANCA, HDAC2, and PALB2. The trial also included HRR-negative patients.
The Zejula combination showed statistically significant improvement in radiographic progression-free survival in patients with alterations in BRCA1/2 and other HRR genes compared to the placebo arm. The investigational combination also improved response rates and delayed initiation of cytotoxic chemotherapy, symptomatic progression, and prostate-specific antigen progression in HRR-positive patients.
Researchers are still collecting data on other endpoints in the ongoing trial including overall survival, time-to-initiation of cytotoxic chemotherapy, and time-to-symptomatic progression.
"The data supporting this submission demonstrate the benefit of niraparib in combination with [abiraterone acetate plus prednisolone] in patients with specific gene alterations and reinforce the importance of biomarker testing in helping to provide an individualized treatment for these patients," Kiran Patel, VP of clinical development for solid tumors at Janssen Research & Development, said in a statement. "We are committed to advancing targeted therapeutic options for patients with prostate cancer as we build upon our deep understanding of the disease with a focus on improving outcomes for patients."
Zejula is already approved in Europe for the treatment of newly diagnosed or relapsed advanced ovarian, fallopian tube, or peritoneal cancer.
In October 2019, the US Food and Drug Administration granted breakthrough therapy designation to Zejula for the treatment of patients with BRCA1/2-mutated metastatic castration-resistant prostate cancer. The drug is also approved in the US to treat advanced ovarian, fallopian tube, or primary peritoneal cancer patients who are homologous recombination deficiency (HRD) positive and as a maintenance treatment for recurrent or advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer.
In 2020, the FDA approved AstraZeneca and Merck's PARP inhibitor Lynparza (olaparib) for mCRPC patients with alterations in HRR genes. However, in the EU, regulators authorized a narrower indication, limiting single-agent Lynparza to mCRPC patients with BRCA1/2 mutations based on results from the PROfound study.