Real-world treatment patterns and overall survival among men with Metastatic Castration-Resistant Prostate Cancer (mCRPC) in the US Medicare population

BackgroundReal-world treatment patterns and survival in metastatic castration-resistant prostate cancer (mCRPC) have not been characterized for the full fee-for-service Medicare population.MethodsMen newly diagnosed with mCRPC were identified in Medicare fee-for-service claims during 1/1/2014-6/30/2019. Men had evidence of mCRPC and continuous insurance coverage >= 1 year before and >= 6 months after diagnosis unless patients died. Treatment patterns after diagnosis were described. Survival from mCRPC diagnosis and from start of first-line (1 L) therapy was modeled using Kaplan-Meier analysis.ResultsAmong 14,780 men with mCRPC, mean age was 76 and median follow-up after mCRPC was 17.0 months. 22% received no life-prolonging therapy after mCRPC, 78% received >= 1 line of therapy (LOT), 42% underwent >= 2 LOTs, and 20% had >= 3 LOTs. Median time from start of 1 L to next LOT or end of follow-up was 13.7 months, 10.9 months from 2 L start, and 8.9 months from 3 L start. The most common 1 L to 2 L treatment sequences among men with >= 2 lines were NHT followed by a different NHT (33%), chemotherapy followed by NHT (14%), and NHT followed by chemotherapy (13%). For those initiating 1 L treatment with NHTs, only 28% received subsequent treatment with a different class of therapy. Median survival was 25.6 months after mCRPC and 23.4 months following treatment initiation.ConclusionsMore than 1 in 5 Medicare patients with mCRPC did not receive any life-prolonging therapy, and less than half received 2 L therapy. NHTs were the most common 1 L and 2 L therapies, with patients treated with NHT as 1 L followed by a different NHT for 2 L as the most common treatment sequence. Median survival from diagnosis for all patients was 25.6 months. These data highlight the dramatic undertreatment that occurs for mCRPC patients, particularly for therapies beyond NHTs as well as the common use of sequential NHTs in real-world data.