CVP alternating with fludarabine (CVP/F) chemotherapy prior to idiotype vaccination for follicular lymphoma (FL)

Abstract

8065 Background: Reducing the tumor burden prior to vaccination facilitates an effective immune response (IR) against the idiotype in FL. In this context, we evaluated the efficacy and toxicity of a novel cytoreductive regimen, CVP/F. Methods: Newly diagnosed, advanced stage FL patients (pt) were treated with CVP (cyclophosphamide 400 mg/m2 PO d1–5, vincristine 2 mg d 1, prednisone 100 mg/m2 d1–5) alternating with F (25 mg/m2 IV d1–5) every 21 days for 2 cycles beyond best response (maximum 8). Pt judged to be cytoreduced adequately were vaccinated monthly × 5 with idiotype protein made from their FL. Results: Among 34 enrolled pt, median age was 45 years (yr), and FLIPI scores were: 18% low, 71% intermediate and 12% high. 38% pt had grade 1 and 62% had grade 2 FL. There were no toxic deaths or opportunistic infections. With 233 cycles (117 CVP and 116 F) given to 33 evaluable pt, neutropenic fever occurred in 7 cycles (3%). 20 cycles (17%) of CVP and 29 cycles (25%) of F were dose reduced for leukopenia. 18 pt (53%) achieved a CR (16) or CRu (2), and 13 pt (38%) had a PR. 22 pt (65%) treated with CVP/F proceeded to vaccination; 10 additional pt (29%) were vaccinated after secondary chemotherapy was given for further cytoreduction. At median follow-up of 11.2 yr, 15-yr overall survival (OS) was 85%. Two of 5 deaths occurred without lymphoma progression. TTF (time to treatment failure = second treatment, relapse, death) at 11 yr was 38%. Anti-idiotype antibody and T cell IR were seen in 44% and 31% pt, respectively. There were no differences in TTF or OS according to IR. Conclusions: CVP/ F was effective in advanced FL, comparing favorably with our historical experience with CVP in terms of CR rate, proportion proceeding to vaccination, TTF and OS after vaccination. This favorable outcome may have been due to the novel alternating CVP/F cytoreductive regimen, idiotype vaccination or both. The idiotype vaccine is now being tested in phase III trials. The CVP/F regimen also warrants further evaluation. No significant financial relationships to disclose.