NEW YORK – Janssen said on Wednesday that it has submitted a new drug application to the US Food and Drug Administration for its PARP inhibitor niraparib plus its hormone agent Zytiga (abiraterone acetate) and the steroid prednisone for metastatic castration resistant prostate cancer (mCRPC) patients whose cancers harbor BRCA mutations.
Janssen is seeking approval for the combination in the form of a dual action tablet for mCRPC patients with BRCA mutations who have not received prior treatment for mCRPC apart from next-generation androgen receptor inhibitors and up to four months of Zytiga plus prednisone.
The application includes the results of the Phase III MAGNITUDE study, in which mCRPC patients with homologous recombination repair (HRR) gene alterations, including BRCA mutations, benefited from the addition of the PARP inhibitor niraparib plus Zytiga versus Zytiga and a placebo. In that trial, patients with HRR gene mutations lived longer without their cancers progressing when treated with niraparib plus Zytiga.
Janssen's FDA submission seeking approval for a PARP inhibitor combination in frontline mCRPC joins the drugmaker's competitors, Pfizer and Merck/AstraZeneca, both of whom are hoping their own PARP inhibitors, Talzenna (talazoparib) and Lynparza (olaparib), respectively, will net approval for this patient population. However, both Pfizer and Merck and AstraZeneca are trying to position their drugs for a broader population of mCRPC patients, regardless of HRR mutation status. Merck and AstraZeneca, who jointly market Lynparza, have already submitted a supplemental new drug application to the FDA for the PARP inhibitor plus Zytiga in an all-comers population, and Pfizer has submitted a supplementary new drug application to the FDA seeking approval for Talzenna plus its hormone therapy Xtandi (enzalutamide) in an all-comers population. As the FDA reviews both of those applications, the oncology community has raised concerns about the degree of benefit these drugs have when given to patients whose tumors do not have HRR gene mutations.
"Patients with mCRPC and BRCA mutations face a more aggressive form of prostate cancer and high unmet needs in terms of treatment options," Peter Lebowitz, the global therapeutic area head of oncology with Janssen Research & Development, said in a statement. "The data supporting this submission reinforce the importance of biomarker testing to identify the subgroups of patients that are most likely to respond to a targeted treatment option."
GSK also markets niraparib for certain ovarian cancer patients under the brand name Zejula. Janssen owns the rights to develop and commercialize niraparib for prostate cancer indications anywhere outside of Japan.