Researchers have identified factors that may predict overall survival of patients with metastatic castrate-resistant prostate cancer (mCRPC) treated with sipuleucel-T, an autologous cellular immunotherapy.
Xiao Wei, MD, and colleagues at the University of California San Francisco reported the findings in an abstract published in conjunction with the American Society of Clinical Oncology annual meeting in Chicago, but not presented at the conference. They reviewed the charts of 43 mCRPC patients (median age 69) treated with a full 3 sipuleucel-T infusions at their institution during 2010 to 2016. Of these patients, 88.4% had bone metastasis with or without positive lymph nodes and 81.4% displayed low metastatic volume. At baseline, median PSA was 8.3 ng/mL and median PSA doubling time (PSADT) was 3.9 months.
With regard to previous treatments, 9.3% of patients had received abiraterone, 2.3% enzalutamide, and 9.3% chemotherapy. Three-quarters of patients (74.4%) had ECOG performance status 0, which indicates an active lifestyle.
Results showed that overall survival was 34.1 months. Using Cox proportional hazard models, the team assessed a host of clinical factors for their possible correlation with survival, including age, ECOG performance status, Gleason score, metastatic volume, baseline PSA, baseline PSADT, prior abiraterone or enzalutamide, and prior chemotherapy.
Univariate analysis showed that ECOG performance and log-transformed PSA significantly related with overall survival. Worse overall survival was found with faster log-transformed PSADT at baseline, as well as prior chemotherapy. After multivariate analysis, only ECOG performance, baseline PSA, and baseline PSADT remained statistically significant.
Some authors disclosed fees or funding from Dendreon Corporation, the makers of sipuleucel-T (Provenge).
Wei X, Perry J, Chang E, et al. Clinical variables associated with overall survival in metastatic castration resistant prostate cancer (mCRPC) patients treated with sipuleucel-T immunotherapy. 2017 ASCO Annual Meeting. J Clin Oncol 35, 2017 (suppl; abstr e16565).