Background: VAP is an new autologous immunomodulate vaccine, that was previously demonstrate to be safe in an initial phase I trial with local advance prostate cancer patients. The extension of this initial trail into a Phase IIb is now been reported. The primary endpoint of the study reported here is clinical response (PSA and survival) in local advance (T2 and T3) prostate cancer patients, with safety and immunologic responses as secondary endpoints.

Methods: Tumor cells from 107 prostatectomy patients were collected (HCPA - Porto Alegre - Brazil). 48 (45%) patients with T3 or T2 with co-morbidity factors were enrolled. 22 patients received the vaccine and 26 were in the control group. Vaccine was given by intradermal injections (4x weekly, 2x monthly and after 3 months). First two doses also ontained BGC as adjuvant. DTH was measured 48 hours after the vaccine doses that did not contained BCG. PBMCs and were collected via apheresis at baseline and D+54 for Tcell proliferation assay in some patients. Clinical flow up was performed and all standard care was given to all patients.

Results: The overall follow up was 7.4 years. No grade 3 or 4 toxicity attributable to vaccine was noted. Side effects were largely limited to grade 1 or 2 injection site reactions. DTH was positive (= or higher than 5 mm) in 73% of the vaccinated patients. Cancer related mortality was 9% (2/22) on the vaccinated group and 19% (5/26) on the non-vaccinated group. PSA was undetectable (less than 0.04 ng/ml) in 85% (17/20) of the vaccinated patients and in 48% (10/21) of the non-vaccinated patients after 5 years of follow up.In vitro specific T cell proliferation was demonstrated in vaccinatedpatients.

Conclusions: VAP is safe and well tolerated vaccine. There is evidence of clinical activity and immune changes in selected patients. Further studies to confirm these results are warranted. (Financial support from FINEP - Brazilian Innovation Agency)

Citation Format: Fernando T. Kreutz, Gustavo Schroeder, Milton Berger. Long term clinical and biochemical outcomes following immunotherapy with an novel autologous immunomodulated vaccine in patients with prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 473. doi:10.1158/1538-7445.AM2013-473