Treatment trends among men with metastatic castration sensitive prostate cancer (mCSPC): Results from the US component of an international study.

66 Background: Novel hormonal therapies (NHTs) and taxane-based chemotherapy (CT) were initially approved for the treatment of metastatic castration resistant prostate cancer (mCRPC) and are now approved for use in mCSPC. Little is known about the recent uptake of these treatments in mCSPC. This study evaluated mCSPC treatment trends from 2016 to 2020 in the US. Methods: Participating physicians collected information from medical charts for the next consecutive 8 men with advanced prostate cancer (4 men with mCSPC, and 4 men with mCRPC) during January-August 2020. A subset of men with current mCRPC had historical mCSPC treatment information available. Treatments were categorized into 4 mutually exclusive categories: (1) androgen deprivation therapy (ADT) ± first-generation anti-androgen (1st gen AA); treatment intensification with (2) NHT, (3) taxane CT ± NHT, and (4) other treatments (e.g., radium-223, sipuleucel-T, non-taxane CT). To account for the availability of new mCSPC treatments, treatment patterns across all lines of mCSPC therapy were described for men initiating treatment in 2016-2018 and 2019-2020. Results: 239 men with mCSPC were included (146 with mCSPC at data collection; 93 with mCRPC at data collection and who had historical information on mCSPC treatments). Mean age was 69 years; 69% had bone metastases and 30% had visceral metastases. Most patients were managed by oncologists (75%), while 48% were treated at academic/cancer centers. From 2016-2018 to 2019-2020, mCSPC treatment intensification with NHT increased while treatment intensification with taxane CT or other therapies declined. (Table) Conclusions: In this real-world study of adult men with mCSPC, increased use of NHT was observed over time indicating that more men will have been exposed to NHT when they progress to mCRPC. This suggests an unmet need for novel therapies in mCRPC. Funding: Pfizer. [Table: see text]