AstraZeneca and MSD have announced that Lynparza (olaparib) has been approved in the US for patients with homologous recombination repair (HRR) gene-mutated metastatic castration-resistant prostate cancer (mCRPC).

The approval by the US Food and Drug Administration (FDA) was based on results from the Phase III PROfound trial, which were published in The New England Journal of Medicine.

“Following this approval for Lynparza in the US, AstraZeneca will receive a regulatory milestone payment from MSD of $35m, anticipated to be booked as Collaboration Revenue by the Company during the second quarter of 2020.”

“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,” says Dave Fredrickson, Executive Vice President, Oncology Business Unit, AstraZeneca.

Following this approval for Lynparza in the US, AstraZeneca will receive a regulatory milestone payment from MSD of $35m, anticipated to be booked as Collaboration Revenue by the Company during the second quarter of 2020.

The PROfound trial

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. Results showed Lynparza reduced the risk of disease progression or death by 66% (equal to a hazard ratio of 0.34; p-value <0.0001) and improved rPFS to a median of 7.4 months versus 3.6 months with enzalutamide or abiraterone.

Lynparza alsoshowed an rPFS benefit in the overall HRR gene-mutated trial population, a key secondary endpoint, and reduced the risk of disease progression or death by 51% (equal to a hazard ratio of 0.49; p-value <0.0001) and improved rPFS to a median of 5.8 months versus 3.5 months with enzalutamide or abiraterone.

Additional results from the PROfound trial announced on 24 April 2020 demonstrated a statistically significant and clinically meaningful improvement in the key secondary endpoint of overall survival (OS) with Lynparza versus enzalutamide or abiraterone in men with mCRPC and BRCA1/2 or ATM gene mutations. Results showed Lynparza reduced the risk of death by 31% (equal to a hazard ratio of 0.69; p-value=0.0175) and improved OS to a median of 19.0 months versus 14.6 months with enzalutamide or abiraterone.

The full indication is for the treatment of adult patients with deleterious or suspected deleterious germline or somatic HRR gene-mutated mCRPC who have progressed following prior treatment with enzalutamide or abiraterone. Patients are to be selected for treatment based on an FDA-approved companion diagnostic test for Lynparza.

Lynparza is currently under regulatory review in the EU and other jurisdictions as a treatment for men with HRR gene-mutated mCRPC. AstraZeneca and MSD are testing Lynparza in additional trials in metastatic prostate cancer including the ongoing Phase III PROpel trial as a 1st-line treatment in combination with abiraterone acetate for patients with mCRPCversus abiraterone acetate alone.

Photo of Dave Fredrickson: AstraZeneca