Phase III Trial of Active Immunotherapy (FavId®, Id/KLH) Following Rituximab Induction Therapy: Clinical Responses in Patients (pts) with Follicular Non-Hodgkin’s Lymphoma (fNHL).
Authors: Freedman Arnold S. , Hamlin Paul A. , Neelapu Sattva , Nichols Craig , Robertson Michael , Bergier Gregoire , Winter Jane N. , Polikoff Jonathan , Lin Thomas , Pohlman Brad , Esquibel Vanessa , Melink Teresa , Bender John 
Published: October 2019

Background: FavId is a personalized immunotherapy comprised of a recombinantly produced idiotype protein (Id) present on a pt’s lymphoma chemically conjugated with keyhole limpet hemocyanin (KLH). A single arm PhII study (Koc et al. Blood2005, 106:11 abstr #772) showed that FavId may improve the clinical response and TTP in both treatment naïve (TN) and relapsed/refractory (R/R) fNHL pts previously treated with rituximab. The results of that study formed the basis for this randomized, double-blind, placebo-controlled PhIII trial of FavId following rituximab (wkly x 4) in TN and R/R pts with fNHL. Randomization was stratified according to prior treatment status (TN vs. R/R) and rituximab response (stable disease (SD) vs. partial response/complete response (PR/CR)). Enrollment to this trial has been completed and follow-up evaluations are ongoing. This report describes clinical responses to rituximab at wk 11, prior to randomization to FavId or placebo.

Objectives: The primary endpoint of this PhIII trial is TTP. Secondary endpoints include response rate improvement (RRI), defined as the percentage of pts with improvement in clinical response after randomization, duration of response and safety. The RRI data are expected to be available in November 2006.

Treatment: Pts received rituximab (375mg/m2 wkly x 4) during wks 1–4. Clinical site assessments for response were performed at wk 11. Pts with stable disease or who had a clinical response to rituximab (PR or CR), were then randomized at wk 12 to receive either FavId or placebo (1 mg s.q. mo x 6) along with GM-CSF (250 mcg, s.q. on days 1–4). Pts continued a booster injection schedule until disease progression.

Results: 364 eligible pts were evaluated for response to rituximab, 286 (79%) were TN and 78 (21%) were R/R. All pts had a good performance status (0 or 1) and the median age was 53 years (22–86 yrs). Baseline data collected to date on the first 272 randomized pts shows 86% had stage 3 or 4 disease. The responses to rituximab are shown below.

Conclusions: Clinical responses to rituximab using a wkly x 4 schedule, including CR rates and SD rates, are not significantly different for TN and R/R pts. Further, >95% of pts treated with rituximab were SD or better at 11 wks and therefore eligible to be randomized. The large numbers of pts with PR or SD at wk 11 post rituximab provide a significant baseline to assess changes in RRI (SD to PR or CR and PR to CR). These data support the design and analysis plan for the PhIII study.

Response to Rituximab at Week 11 Response TN (N=286) Relapsed (N=78) Total (N=364) ORR (CR + PR) 163 (57%) 43 (55%) 206 (57%) CR 20 (7%) 4 (5%) 24 (7%) PR 143 (50%) 39 (50%) 182 (50%) SD 110 (38%) 31 (40%) 141 (39%) PD 13 (5%) 4 (5%) 17 (5%)