Data from A Comparative Analysis of Prognostic Factor Models for Follicular Lymphoma Based on a Phase III Trial of CHOP–Rituximab versus CHOP + &lt;sup&gt;131&lt;/sup&gt;Iodine—Tositumomab

Mark Kaminski,Shaker R Dakhil,Richard I Fisher,Ajay K Gopal,Rita M Braziel,Joseph M Unger,Myron S Czuczman,David G Maloney,Thomas P Miller,Oliver W Press,Jonathan W Friedberg,Lisa M Rimsza,Michael Leblanc,Catherine Spier,Bruce D Cheson

doi:10.1158/1078-0432.c.6521750.v1

Abstract

<div>AbstractPurpose: There is currently no consensus on optimal frontline therapy for patients with follicular lymphoma. We analyzed a phase III randomized intergroup trial comparing six cycles of CHOP-R (cyclophosphamide–Adriamycin–vincristine–prednisone (Oncovin)–rituximab) with six cycles of CHOP followed by iodine-131 tositumomab radioimmunotherapy (RIT) to assess whether any subsets benefited more from one treatment or the other, and to compare three prognostic models.Experimental Design: We conducted univariate and multivariate Cox regression analyses of 532 patients enrolled on this trial and compared the prognostic value of the FLIPI (follicular lymphoma international prognostic index), FLIPI2, and LDH + β2M (lactate dehydrogenase + β2-microglobulin) models.Results: Outcomes were excellent, but not statistically different between the two study arms [5-year progression-free survival (PFS) of 60% with CHOP-R and 66% with CHOP-RIT (P = 0.11); 5-year overall survival (OS) of 92% with CHOP-R and 86% with CHOP-RIT (P = 0.08); overall response rate of 84% for both arms]. The only factor found to potentially predict the impact of treatment was serum β2M; among patients with normal β2M, CHOP-RIT patients had better PFS compared with CHOP-R patients, whereas among patients with high serum β2M, PFS by arm was similar (interaction P value = 0.02).Conclusions: All three prognostic models (FLIPI, FLIPI2, and LDH + β2M) predicted both PFS and OS well, though the LDH + β2M model is easiest to apply and identified an especially poor risk subset. In an exploratory analysis using the latter model, there was a statistically significant trend suggesting that low-risk patients had superior observed PFS if treated with CHOP-RIT, whereas high-risk patients had a better PFS with CHOP-R. Clin Cancer Res; 19(23); 6624–32. ©2013 AACR.</div>

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