SAN FRANCISCO, CA USA (UroToday.com) - This abstract was presented by Dr. Uemura and colleagues from Japan. This group reported on a randomized phase II trial to evaluate the efficacy of peptide vaccination therapy for chemotherapy-naive CRPC patients.
The primary endpoint of their study was progression-free survival, including serum PSA, with secondary endpoint being overall survival and safety. Early-stage CRPC (PSA< 10ng/ml) patients positive for HLA-A02 or A24 or A3 super family were randomized into 2 treatment groups -- peptide vaccine with low dose (1mg/day) dexamethasone (Dx) versus low dose Dx alone. Patients were vaccinated subcutaneously with 3 mg of selected peptides (max. 4 kinds) 6 times at 2-week intervals. Dx 1mg/day p.o. was started on the first day of peptide vaccination. Toxicity was assessed monthly, and immunological responses such as cytotoxic T-lymphocyte activity and clinical responses were evaluated every 3 months.
A total of 83 chemotherapy-naive CRPC patients were enrolled into the trial. Of these, 10 patients were excluded due to HLA type mismatch and exclusion criteria. Seventy-three patients were then randomized (37 in the vaccine treatment group and 36 in the Dx group). They reported a median time of 602 days to PSA failure in the vaccine group vs 210 days in the controlled arm (p < 0.001). They concluded that combination therapy of peptide vaccines and low dose dexamethasone may be a promising tool for chemotherapy-naive CRPC patients.
Highlights of a presentation by Hirotsugu Uemura at the 2014 Genitourinary Cancers Symposium - January 30 - February 1, 2014 - San Francisco Marriott Marquis - San Francisco, California USA
Department of Urology, Kinki University Faculty of Medicine, Osaka, Japan