The PARP inhibitor olaparib is now available on the PBS for the treatment of metastatic castration-resistant prostate cancer (mCRPC ) in men with BRCA1 and BRCA2 pathogenic gene variants.

From 1 April the daily oral medication will be listed on the PBS as a treatment for men with BRCA-mutated (germline and/or somatic) castration-resistant metastatic carcinoma of the prostate who have progressed following prior therapy that included a novel hormonal agent. The listing will provide access to treatment for about 200 men who would otherwise pay $80,000 for olaparib, said health minister Greg Hunt.

Already on the PBS for ovarian cancer, the listing for mCRPC was approved by the PBAC at its November 2021 meeting, at which it concluded that olaparib provided, for some patients, a significant improvement in efficacy over standard care based on the results of the PROfound study.

Published in 2020, the results of the PROfound trial showed that olaparib was associated with longer progression-free survival and better measures of response and patient-reported end points than either enzalutamide or abiraterone in men who had disease progression while receiving these novel hormonal agents.

The PBAC noted that the current clinical management algorithm depicted three lines of treatment in mCRPC; with novel hormonal agent or docetaxel as first-line; best supportive care, novel hormonal agent, cabazitaxel or docetaxel in second line; followed by best supportive or cabazitaxel in third line.

“Olaparib is proposed to be used as monotherapy following progression with NHA treatment. It may be used as either first line, second line or third line therapy in mCRPC. This is broadly consistent with the TGA indication (“treatment of adult patients with BRCA-mutated (germline and/or somatic) mCRPC who have progressed following prior therapy that included an NHA),” the proposal noted.

According to a statement from sponsor AstraZeneca, BRCA mutations affect 10–12% of men with mCRPC, and the listing of olaparib highlighted the importance of testing for BRCA mutations in mCRPC as early as possible to identify men who will be eligible for treatment.

“Those diagnosed should ask their clinician to conduct a tumour test to determine whether they have a BRCA mutation, so they can be given a treatment specifically for their type of cancer,” it said.

This was supported by Associate Professor Shahneen Sandhu, a consultant medical oncologist and a researcher in the melanoma and uro-oncology units at the Peter MacCallum Cancer Centre, Melbourne, who said: “Molecular testing has been done for a long time in many other cancers such as lung, colorectal and melanoma and now should also be routinely discussed with patients with advanced prostate cancer”.

“Unfortunately, patients with mCRPC often have disease related symptoms such as bone pain and tiredness that can affect their quality of life. It is great news that men with aggressive BRCA1/2 mutant advanced prostate cancer will now be able to access another treatment option on the PBS,” he added.