Clinical trial NCT00694551
Conditions: Prostate Cancer
Keywords: vaccine PSMA TARP immunology PSA
Sponsor: H. Lee Moffitt Cancer Center and Research Institute
Start date: 2008-12-02; Completion date: 2018-12-06
Enrollment: 29 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
Pilot Immunotherapy Study of Combination Prostate Specific Membrane Antigen (PSMA) and T-cell receptor γ alternate reading frame protein (TARP) Peptide With Poly IC-LC Adjuvant in Human Leukocyte Antigens (HLA)-A2 (+) Patients With Elevated prostatic specific antigen (PSA) After Initial Definitive Treatment

The purpose of the study is to see if the PSMA/TARP proteins in the vaccine, along with the Hiltonol, can arouse and train the immune system to kill the prostate cancer cells. Prostate cancer is the most common cancer and is the second leading cause of cancer deaths in U.S. males. It is curable when it is confined to the prostate (kept from spreading) using surgery or radiation treatments. In some patients the cancer can come back after these treatments. Treatment options for prostate cancer that comes back include procedures or medications which may have significant risks and side effects. Another plan is being looked at that uses the body's immune system to attack prostate cancer cells. A vaccine has been developed that has proteins found in prostate cancer cells. One of the proteins is called PSMA and the other is called TARP. In addition to these proteins, another substance called Poly IC-LC (Hiltonol) will be added to the vaccine to boost its ability to start the immune system.

Detailed description:
Detailed Objectives:

1. Estimate the frequency of immunological efficacy of the vaccine by comparison of the in vitro enzyme-linked immunosorbent spot (ELISpot) test results, for each antigen (PSMA, TARP) from peripheral blood specimens collected during the periods of time defined as "before", "during" and "after" vaccination.
2. Study the safety and toxicity of varying doses of polypeptide vaccines: PSMA27-35-PSMA687-701 (VLAGGFFLLYRHVIYAPSSHNKYA) and TARP13-35 (LQLLKQSSRRLEHTFMFLRNFSL) administered with a fixed dose of Poly IC-LC (2 mg total/treatment) as adjuvant.
3. Describe the impact of the vaccine on the pattern of PSA change in 2 subsets of patients: with castrate testosterone; with non-suppressed testosterone level/not on hormone therapy.
4. Identify if there is a basis for selection of a dose of the PSMA and the TARP polypeptide vaccines for future phase II development of this vaccination strategy, considering the dose range tested.

Arms: arm 1: Peptide vaccine dose level 100 mcg + Poly IC-LC arm 2: Peptide vaccine dose level 300 mcg + Poly IC-LC arm 3: Peptide vaccine dose level 1 mg + Poly IC-LC
Interventions: intervention 1: Peptide Vaccine intervention 2: Poly IC-LC
Intervention descriptions: intervention 1: Peptide vaccine (PSMA and TARP peptide vaccine with Poly IC-LC adjuvant). Pilot study using three treatment arms of increasing peptide dose levels (100 mcg, 300 mcg, and 1 mg) with a fixed dose of Poly IC-LC as an adjuvant. Patients were randomly assigned to one of the 3 arms upon enrollment. intervention 2: Administered subcutaneously, one 2 mg/ml vial,(divided into two equal portions for each injection site).

Protocol documents: