AstraZeneca and Merck (MSD) have received the US Food and Drug Administration (FDA) approval for Lynparza (olaparib) to treat a type of metastatic castration-resistant prostate cancer (mCRPC).

Lynparza is a PARP inhibitor and the first targeted treatment to block DNA damage response (DDR) in cells or tumours sheltering a deficiency in homologous recombination repair.

The US regulatory agency has indicated Lynparza to treat patients with homologous recombination repair (HRR) gene-mutated mCRPC.

AstraZeneca oncology business unit executive vice president Dave Fredrickson said: “Today marks the first approval for Lynparza in prostate cancer.

“In the PROfound trial, Lynparza more than doubled the median radiographic progression-free survival and is the only PARP inhibitor to improve overall survival, versus enzalutamide or abiraterone for men with BRCA or ATM mutations.

“These results further establish that genomic testing for HRR mutations should be a critical step for the diagnosis and determination of treatment options for men with advanced prostate cancer.”

The FDA approval for Lynparza was based on results from the Phase 3 PROfound trial

The FDA approval was supported by results from the Phase 3 PROfound trial, a multicentre, randomised, open-label study that evaluated the efficacy and safety of Lynparza, compared to enzalutamide or abiraterone.

The primary endpoint of the trial was radiographic progression-free survival (rPFS) in men with BRCA1/2 or ATM gene mutations, a subpopulation of HRR gene mutations.

The study results showed that Lynparza reduced the risk of disease progression or death by 66% and improved rPFS, compared to enzalutamide or abiraterone.

In addition, Lynparza has also reached a key secondary endpoint, by showing an rPFS benefit in the overall HRR gene-mutated trial population, and reduced the risk of disease progression or death by 51% and improved rPFS than enzalutamide or abiraterone.

PROfound trial principal investigators Maha Hussain said: “Prostate cancer has lagged behind other solid tumours in the era of precision medicine.

“I am thrilled by the approval of Lynparza which now brings a molecularly targeted treatment to men with HRR gene-mutated metastatic castration-resistant prostate cancer in the US.

“The PROfound trial was an international effort and I want to thank the patients, their families, the investigators and their teams involved in making it possible.”

Lynparza is currently BEING reviewed in the EU and other jurisdictions for regulatory approval as a treatment for men with HRR gene-mutated mCRPC.

AstraZeneca and MSD are testing Lynparza in several metastatic prostate cancer trials, including the ongoing Phase 3 PROpel trial as a 1st-line treatment in combination with abiraterone acetate for patients with mCRPC versus abiraterone acetate alone.

MSD Research Laboratories senior vice president and global clinical development head Roy Baynes said: “Lynparza is the only PARP inhibitor approved with Phase III data for men with HRR gene-mutated metastatic castration-resistant prostate cancer.

“This approval highlights the importance of genomic testing to help identify treatment options for men in this patient population. We are proud to work in collaboration with AstraZeneca toward our overall goal of improving outcomes for patients.”