The FDA companion diagnostic designation for FoundationOne CDx may improve access to treatment with niraparib/abiraterone acetate dual action tablets in those with metastatic castration-resistant prostate cancer harboring a BRCA mutation.
The FDA has approved the FoundationOne CDx as a companion diagnostic for identifying patients with deleterious or suspected deleterious BRCA-mutated metastatic castration-resistant prostate cancer (CRPC) who may benefit from treatment with niraparib and abiraterone dual action tablets (Akeega), according to a press release from Foundation Medicine Inc.1
“With such a rapidly evolving therapeutic landscape in prostate cancer, high-quality companion diagnostics are important tools to support oncologists in the development of personalized treatment plans for each unique patient,” Mia Levy, MD, PhD, chief medical officer at Foundation Medicine, said in the press release. “This companion diagnostic specifically will help enable broader access to an important new therapy option in [BRCA1/2-mutated metastatic] CRPC.”
The FDA previously approved niraparib plus abiraterone acetate and prednisone for patients with BRCA-positive metastatic CRPC in August 2023.2 Supporting data for this approval came from the phase 3 MAGNITUDE trial (NCT03748641), in which investigators reported a 47% reduction in the risk of radiographic progression-free survival (rPFS) in the niraparib arm compared with placebo (HR, 0.53; P = .001). With a median follow-up of 24.8 months, the median rPFS by independent central review in the experimental and placebo arms, respectively, was 19.5 months vs 10.9 months (HR, 0.55; 95% CI, 0.39-0.78).
“We prospectively designed the MAGNITUDE study to identify the subset of patients most likely to benefit from targeted treatment with [niraparib and abiraterone acetate] and to help us understand how we can potentially achieve better health outcomes for patients,” principal investigator Kim Chi, MD, a medical oncologist at BC Cancer – Vancouver, said in a press release at the time of the agent’s FDA approval.2
The FoundationOne CDx, a next-generation sequencing device, is designed to detect insertion and deletion alterations, as well as substitutions across 324 genes, helping to identify patients who may be eligible to receive targeted therapies based on approved therapeutic product labelling.
According to the press release, the assay is intended exclusively for prescription use. Additionally, testing with the FoundationOne CDx does not guarantee that a patient will be matched to a treatment, and a negative test result does not negate the potential presence of an alteration.
The FDA approved the FoundationOne Liquid CDx assay in August 2020, which included an indication for rucaparib (Rubraca) as a treatment for patients with BRCA-mutated metastatic CRPC.3 The FDA also approved the FoundationOne Liquid CDx as a companion diagnostic for identifying patients with metastatic CRPC harboring a BRCA1/2 and/or ATM alteration who may be eligible to receive treatment with olaparib (Lynparza) in November 2020.4