SNP Genotypes Show Association with Common Toxicities during both VAD Induction and High Dose Melphalan with Autologous Transplant Support in Intergroup Trial S9321 for Myeloma: From the Bank on a Cure.

Patients with multiple myeloma show significant heterogeneity with respect to progression, therapeutic response and toxicities. Part of the Bank On A Cure project is to examine potential genetic polymorphisms that may be associated with common toxicities monitored in clinical trials. The SWOG/ECOG intergroup trial S9321 therapy includes VAD induction followed by randomization to high dose melphalan with autologous transplant support. Paticularly important toxicities with VAD include infection, thrombosis and hyperglycemia; and with melphalan toxicities in GI function are noted. Toxicities and genotypes were assessable during VAD induction on 569 patients; and during high dose melphalan on 161 patients. Toxicities examined included an array of symptoms: cardiovascular, flu-like, GI, neurologic, infection, lung, metabolic, and pain. Grade 3 toxicities found in at least 20 patients were compared to SNP genotypes. For VAD induced toxicities,TNF-alpha SNP genotypes showed association with fatigue, dyspnea and thrombosis; CYP3A4 SNP genotypes showed association with fatigue; DNA repair SNP genotypes in XRCC1 showed associations with infection, hyperglycemia and dyspnea; LT-alpha SNP genotypes showed association with dyspnea; and IL-6 and IL-10 SNP genotypes were marginally associated with neuropathy. After high dose melphalan, diarrhea was associated with SNP genotypes in TGF-beta, CYP3A4 and ERCC2. Interestingly, IL-6 polymorphisms were significantly associated with infection. The p values on the above associations ranged from .05 to .004. In addition, we noted ethnic distributions of some SNP genotypes were significantly different; and significant ethnic disparities in therapy induced hyperglycemia, fatigue, dyspnea and thrombosis were noted (p values range from .04 to .009). Of particular note is that the high producer IL-6 genotype is present in over 90% African Americans, compared to 35% Caucasians. Details of each association will be presented. Not all associations can easily be explained by known biologic function of the genotype, and it is important to qualify these results, as the likelihood of seeing some genotype associations by chance is quite high given the number of comparisons made. Further, we are continuing to examine additional prognostic factors that may, together with genotypes, provide collective predictors of toxicities. We consider these associations as targets for further study through the increasing sample acquisition in the Bank On A Cure project.