Treatment patterns for patients with BRCA1/2-positive metastatic castration-resistant prostate cancer.

Background: Patients with BRCA-positive metastatic castration-resistant prostate cancer (mCRPC) have an aggressive disease course. This study aimed to describe real-world treatment patterns among patients with BRCA-positive mCRPC.

Materials And Methods: De-identified electronic health record data from the Flatiron Health-Foundation Medicine Inc. Metastatic Prostate Cancer Clinico-Genomic Database (January 01, 2011 to June 30, 2022) were used to select patients with BRCA-positive mCRPC initiating first-line (1L) therapy with an oncologist-defined advanced line of therapy (LOT) or androgen deprivation therapy (ADT) monotherapy. Treatment sequences and reasons for censoring were described in 1L, and among patients who initiated a second-line (2L) therapy.

Results: A total of 98 treated patients with BRCA-positive mCRPC were identified. The top 3 treatment regimens in 1L, overall, were ADT monotherapy (19%), enzalutamide (14%), and olaparib (13%). The main reason for censoring patients with ADT monotherapy was death (52.6%). Among 79 patients treated with an advanced LOT in 1L, 43.0% (n = 34) did not initiate a 2L therapy, of which, 29.4% died. In patients who initiated a 2L (n = 45), the most common 1L to 2L treatment sequence was olaparib to docetaxel (11.1%). The most prescribed 2L therapies were docetaxel (22.2%), olaparib (20.0%), abiraterone acetate (13.3%), and enzalutamide (11.1%). From 1L initiation, the median time-to-next-treatment was 6.2 months.

Conclusion: Among patients with BRCA-positive mCRPC, ADT monotherapy, enzalutamide, and olaparib were most commonly used. Prognosis of BRCA-positive patients was poor, with most patients failing initial therapy resulting in a switch to a new therapy or death. These findings highlight the need for earlier and more effective treatments for patients with BRCA-positive mCRPC.