Conditions: Prostate Cancer Metastatic Hormone Refractory Prostate Cancer Castration-resistant Prostate Cancer
Keywords: prostate cancer prostate androgen independent prostate cancer (AIPC) androgen-independent androgen independent hormone insensitive hormone-insensitive prostate specific antigen (PSA) prostatic adenocarcinoma hormone-refractory hormone refractory hormone refractory prostate cancer (HRPC) immune therapy immunotherapy vaccine dendritic cells antigen-presenting cells antigen presenting cells cancer vaccine therapeutic vaccine therapeutic cancer vaccine recombinant biological biopharmaceutical biotechnology biotech castration resistant prostate cancer (CRPC) castration-resistant prostate cancer (CRPC) castration-resistance sipuleucel-T abiraterone prednisone sequence sequencing
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 69
Healthy volunteers: no

Brief summary:
The purpose of this study was to evaluate the impact of concurrent versus sequential administration of abiraterone acetate plus prednisone on the ability to manufacture sipuleucel-T (by assessing sipuleucel-T product parameters), and to assess the safety and efficacy of sipuleucel-T with concurrent or sequential administration of abiraterone acetate plus prednisone in men with metastatic castrate resistant prostate cancer.

Detailed description:
Subjects underwent screening procedures at the Screening Visit to ensure that they met the inclusion and exclusion criteria outlined in the protocol. Subjects were evaluated for eligibility criteria, and if eligible, were registered and randomized in a 1:1 into either the Concurrent Arm or the Sequential Arm.

Subjects in both arms underwent a standard 1.5 to 2.0 blood volume leukapheresis, followed approximately 3 days later by an intravenous (IV) infusion of sipuleucel-T. This process occurred at approximately 2-week intervals. A course of sipuleucel-T treatment comprised three infusions.

Following the first infusion, subjects were limited to a maximum of three total product failures for all subsequent infusions, due specifically to insufficient total nucleated cell (TNC) count and/or CD54 upregulation. These subjects received no further leukaphereses or sipuleucel-T infusions, but did receive abiraterone acetate plus prednisone per the schedule of the arm to which they were randomized. All subjects received a total of 26 weeks of abiraterone acetate plus prednisone therapy.

All immune monitoring (IM) endpoints were collected from all subjects who received at least one infusion. Cellular and serological immune responses were assessed for subjects in both arms. In both arms, IM blood samples were collected at baseline (screening); pre-leukapheresis 2 and 3; post-infusion 1, 2, and 3; and weeks 6, 10, 14, and 26, with the timing of IM visits based on the onset of treatment (Day 0). Day 0 was the day of the first infusion. Post-infusion blood draws occurred at 3 hours (allowable window 1-24 hours) after each infusion. If a subject received only one or two infusions, immune samples were still drawn at the scheduled time points based on the first infusion (Day 0). If the subject was not scheduled to undergo further leukapheresis, no other pre-leukapheresis procedures were conducted.

During the active follow-up phase, subjects were followed from registration through the Post-Treatment Visit (30-37 days post-last study treatment), or until disease progression, unacceptable toxicity, or death, whichever occurred first.

During the long-term follow-up (LTFU) phase, subjects were followed from the Post-Treatment Visit for up to 3 years from the date of registration/randomization. During the LTFU phase, only new treatment-related serious adverse event (SAE)s, cerebrovascular event (CVE)s (regardless of causality), the first anti-cancer therapy and first chemotherapy, and survival status were collected via a quarterly telephone call.

Overall survival was measured as the time from randomization until death over a 3-year period.

Arms:
arm 1: Subjects received sipuleucel-T concurrent with abiraterone acetate plus prednisone. Abiraterone acetate plus prednisone treatment started the next day after the first infusion of sipuleucel-T and continued for 26 weeks or until disease progression, unacceptable toxicity, or death, occurred. arm 2: Subjects received sipuleucel-T therapy followed by abiraterone acetate plus prednisone. Abiraterone acetate plus prednisone started at week 10 from the start of the first infusion of sipuleucel-T and continued for 26 weeks or until disease progression, unacceptable toxicity, or death, occurred.

Interventions: intervention 1: sipuleucel-T intervention 2: abiraterone acetate
Intervention descriptions: intervention 1: Sipuleucel-T is an autologous cell product consisting of antigen presenting cells (APCs) loaded with PA2024, a recombinant fusion protein composed of prostatic acid phosphatase (PAP), linked to granulocyte-macrophage colony-stimulating factor (GM-CSF). intervention 2: Abiraterone acetate (1000 mg po QD) was administered in combination with prednisone (5 mg po BID) for a total of 26 weeks.

Protocol document: