Abstract
Abstract only 185 Background: Sip-T is an autologous cellular immunotherapy indicated for asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC). PROCEED is an ongoing phase 4 registry, enrolling pts receiving commercial sip-T. There are no exclusions based on prior prostate cancer treatments, so sip-T product parameters can be evaluated in pts receiving prior hormonal agents such as ABI or ENZ. Methods: Pts treated with sip-T within ≤6 mo were eligible to provide informed consent. Prior anticancer interventions were recorded at baseline. Sip-T product parameters were assessed. Results: Of 1,376 pts (as of May 2013), 108 (7.8%) received prior ABI and 58 (4.2%) received ENZ. Patients with ABI or ENZ generally had more advanced disease vs. pts without prior ABI or ENZ (WPT) and a greater proportion of the ABI and ENZ pts received prior docetaxel. There were slight differences in some sip-T product parameters in the ABI and ENZ groups, but neither manufacture nor receipt of sip-T were inhibited, as indicated by the percentage of pts with 3 successful infusions. All groups showed evidence of immune prime boost (Table). Conclusions: A subset of patients in PROCEED have received ABI or ENZ prior to sip-T. We observed no impact of prior ABI/ENZ on sip-t manufacturing or delivery, despite these men having more advanced disease. These results are consistent with prior analyses demonstrating a positive sip-T treatment immune effect in patients who have received prior therapies, including chemotherapy. Further immune monitoring and outcome studies are currently ongoing in the pre-docetaxel mCRPC setting where these agents will likely be used clinically. Clinical trial information: NCT01306890. [Table: see text]