Impact of Prior Treatments on Clinical Outcomes in Patients With Metastatic Castration-Resistant Prostate Cancer—A Real-World Analysis in the United States

This retrospective, real-world study found that about one-third of patients between 2016 and 2023 received treatment intensification for prostate cancer before a diagnosis of metastatic castration-resistant prostate cancer (mCRPC) and use of treatment intensification increased over time.Outcomes in first-line mCRPC varied by prior treatment.Novel therapies and combinations are needed for patients with mCRPC who receive prior treatment intensification. Clinical Practice PointsTreatment intensification (the addition of an androgen-receptor pathway inhibitor [ARPi] or chemotherapy to androgen deprivation therapy [ADT]) has been shown to provide clinical benefit for patients with non-metastatic castration-sensitive prostate cancer (nmCSPC) and a high-risk of biochemical recurrence, mCSPC, and non-metastatic castration-resistant prostate cancer (nmCRPC). However, it is unclear how treatment intensification in these settings impacts (1) treatment selection for patients after diagnosis with mCRPC and (2) clinical outcomes in these patients. This retrospective, real-world study of patients with mCRPC between January 2016 and December 2023 found that 73.9% of patients (56.1% in 2023) did not receive treatment intensification in prior disease settings, highlighting the need for further adoption of treatment intensification for patients before they are diagnosed with mCRPC. We also report that clinical outcomes in mCRPC varied by prior treatment received, with patients who had received prior ARPi treatment (alone or in combination with a taxane), compared with those who hadn't, having nominally shorter median time to prostate-specific antigen progression or death, and nominally shorter median overall survival.(76.8%) of patients received an ARPi as 1L treatment for mCRPC.In the overall population, median TTPD was 12.1 months and trended lower for patients who had received prior ARPi-only treatment.Overall median OS was 24.6 months and trended lower for patients who received prior ARPi only or both prior ARPi and taxane. Conclusion:Despite increased use of chemotherapy and ARPis prior to mCRPC, treatment intensification is underutilized.Clinical outcomes in patients receiving 1L treatment for mCRPC varied by prior treatment received, highlighting the need for novel therapies and optimal treatment sequencing.