Abstract 2

Idiotype vaccine therapy (BiovaxID) in follicular lymphoma in first complete remission: Phase III clinical trial results

S.J. Schuster, S.S. Neelapu, B.L. Gause, et al

Methods: This phase III prospective randomized double-blind placebo-controlled trial enrolled 234 previously untreated advanced-stage FL patients, of whom 177 (76%) achieved a complete response to PACE (prednisone, doxorubicin [Adriamycin], cyclophosphamide, etoposide). Patients who maintained a CR/Cru (unconfirmed complete response) for at least 6 months were then randomized to receive the Id-KLH + GM-CSF vaccine or the control KLH + GM-CSF vaccine. Patients who received at least one dose of the assigned vaccine (n = 76 Id-KLH; n = 41 control KLH) constituted the modified intent-to-treat population for the determination of efficacy.

Results: At a median follow-up of 56 months, the median time to relapse after randomization was 44.2 months in the Id-KLH arm and 30.6 months in the control KLH vaccine arm (HR = 1.6; P = 0.05). Disease free-survival (DFS) for patients who relapsed after randomization but before vaccination (n = 60) was 6.1 months with the Id-KLH vaccine and 5.9 with the control vaccine (P = 0.78). Median overall survival has not been reached in either group; at follow-up, 95.4% of the Id-KLH cohort is alive compared to 91.2% of the control arm. Adverse events were rare and no serious adverse events were attributed the Id-KLH vaccine.

Conclusions: The Id-KLH + GM-CSF vaccination improved DFS after chemotherapy in patients who achieved a complete response prior to vaccination. Complete response could be a prerequisite for achieving benefit from such vaccination. Long-term clinical experience with idiotype vaccination demonstrated low toxicity. Tumor-specific idiotype vaccine can be successfully manufactured.