A panel of U.S. Food and Drug Administration advisers on Friday voted for the restricted use of British drugmaker AstraZeneca Plc's experimental treatment, jointly developed with Merck & Co, for a type of prostate cancer.

The FDA panel voted 11-1 with one abstention, in favor of Lynparza, in combination with other medications – abiraterone and prednisone or prednisolone – as a first-line treatment for a type of treatment-resistant prostate cancer in adult patients.

However, the panel recommended the approval to be limited only to patients whose tumors have a mutation in the BCRA genes, and advised against approval beyond this patient population.

Its recommendation comes after Lynparza and similar class of therapies suffered a series of safety setbacks as clinical data suggested that patients do not live as long as those given chemotherapy when given as a second-line therapy.

Lynparza belongs to a class of drugs called PARP inhibitors, which include Clovis Oncology's Rubraca and GSK Plc's Zejula.

They were withdrawn last year as second line of treatment for ovarian cancer patients after the FDA limited the use of PARP inhibitors and requested companies to pull the drug.

Friday's vote is based on a late-stage study, which showed Lynparza in combination significantly improved duration for which patients live without disease worsening when compared to the placebo in combination with abiraterone and prednisone/prednisolone.

Lynparza is already approved by the FDA to treat a type of breast cancer, ovarian cancer, as well as a different form of prostate cancer.

The FDA while making its final decision on the use of the drug usually follows the recommendations of its expert panel but is not obligated to do so.