Genetic Polymorphisms Associated with Clinical Outcome in the Intergroup Trial S9321, Comparing High Dose Therapy with Standard Dose Therapy for Myelomaon, on Behalf of ECOG, SWOG, CALGB, and the Bank on a Cure.

Abstract

Genetic variations in patient populations likely contribute to disease progression and therapeutic outcomes. We have begun a systematic approach to examine the association of genetic variations (ie. functional, single nucleotide polymorhisms, SNPs) involved in myeloma growth promotion, metabolic events, drug responses, and DNA repair on clinical outcome in the intergroup trial S9321. This trial tested a single high dose regimen with autologous stem cell support against a conventional dose regimen, with further randomization of responders to maintenance with interferon or not, in newly diagnosed patients with multiple myeloma. ECOG, CALGB and SWOG enrolled 899 patients with newly diagnosed MM to receive VAD induction x 4 cycles followed by randomization to PBSC-supported high dose therapy (HDT) versus standard dose therapy (SDT) of VBMCP, using CTX 4.5 g/m2 + G-CSF for PBSC mobilization in all patients. Responders to VBMCP or HDT were randomized to IFN or no maintenance. Specimens were distributed through ECOG for biologic correlative studies, including candidate SNP analysis. SNP assays have been developed using the Sequenom Mass-extend platform for functional SNPs in IL-6, IL-1, IL-RA, IL-10, TNF, Lta, TGFb, MDR1, MPO, CYP3A4, GST (M, P, T), ERCC2 and XRCC1, and are being evaluated on 803 DNA samples prepared from patients enrolled in S9321. Preliminary findings (n=135) demonstrate functional genetic variants of IL-10 (position -1082), IL-1 (position +3953), TGFb (postion -509), and TNFa (position -308) are showing trends associated with differences in progression free survival; and variants in IL-6 (position -174) are associated with response. Median survival of the IL-10 variants was 31 months for A/A low producer alleles versus 19 months for the G/G high producer alleles (p=.5). For TNFa, 2 cases with the high producer A/A alleles died within a year, while the median survival for the lower producer G/G alleles was 2 years (p=.04). For patients with the high producer C/C/ allele of IL-1 (n=67), median survival was 2 years, versus 5 patients with the T/T low producer alleles that had a median survival greater than 5 years (preliminary p=.29). While these preliminary results are now only suggestive of trends in genetic polymorphisms associated with clinical outcome, completion of the full SNP panel on the entire sample base should provide a extensive association study, and analysis of potential differences in therapy arms of the trial. The full panel and association studies will be presented.ααββααα