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.
Abstract 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.
SNP Associations with Event Free Survival in Myeloma from Two Phase III Clinical Trials Using the Bank On A Cure Chip.
Abstract While there are certain common clinical features in myeloma, the disease shows significant heterogeneity with regard to disease progression, and responses to therapy, affecting both survival and toxicities. Heritable variations in a wide variety of genes and pathways affecting cellular functions and drug responses likely impact patient outcomes. In the Bank On A Cure (BOAC) program we have developed a custom chip that assesses 3,404 SNPs representing variations in cellular functions and pathways that may be involved in myeloma progression and response. The chip has gone through rigorous quality controls checks for high call rates, accuracy, and reproducibility that will be presented. Using the BOAC chip, we have conducted studies to look for SNPs that may identify biologic variations that are associated with good or poor response across a variety of treatments. In this study we looked for SNPs that may distinguish short term and long term survivors in two phase III clinical trials: ECOG E9486 and intergroup trial S9321. E9487 patients were treated with VBMCP followed by randomization to no further treatment, IFN-alpha, or cylcophosphamide; and, although there was variation in survival, no significant differences in survival were noted among the 3 arms of the trial. Patients included in this SNP study from S9321 received VAD induction followed by randomization to VBMCP or high dose melphalan + TBI. SNP profiles were obtained for patients with less than 1 year EFS (n=20 in E9487; n=50 in S9321) and patients showing greater than 3 years EFS (n=32 in E9486; n=41 in S9321). Statistical approaches were performed to identify single and groups of SNPs that best discriminated the survival groups. Previous studies have suggested genetic variations in drug metabolism genes, p-glycoprotein transport, and DNA repair genes may influence survival outcomes. Our results show significant survival associations of genetic variations in genes within these functional categories (eg. GST, XRCC, ABCB, and CYP genes). Although genetic variations were found that were uniquely associated with each clinical trial, several of these genetic variations show survival associations that increase in significance when the two trials were examined as a conglomerate data set. Grouping genetic variations through common pathway approaches using gene set enrichment analysis, as well as clustering or partitioning algorithms, further improve the value of the SNPs as potential prognostic markers of survival outcomes. These results and statistical approaches will be presented, and represent steps toward identifying patient variations in biologic mechanisms important in predicting therapeutic outcomes.
Standard Chemotherapy Compared With High-Dose Chemoradiotherapy for Multiple Myeloma: Final Results of Phase III US Intergroup Trial S9321
Purpose Results of a prospective randomized trial conducted by the Intergroupe Francais du Myélome (IFM 90) indicated that autologous hematopoietic cell–supported high-dose therapy (HDT) effected higher complete response rates and extended progression-free survial (PFS) and overall survival (OS) compared with standard-dose therapies (SDT) for patients with multiple myeloma (MM). Patients and Methods In 1993, three North American cooperative groups launched a prospective randomized trial (S9321) comparing HDT (melphalan [MEL] 140 mg/m 2 plus total-body irradiation 12 Gy) with SDT using the vincristine, carmustine, MEL, cyclophosphamide, and prednisone regimen. Responders on both arms (≥ 75%) were randomly assigned to interferon (IFN) or no maintenance treatment. Results With a median follow-up time of 76 months, no differences were observed in response rates between the two study arms (HDT, n = 261 patients; SDT, n = 255 patients). Similarly, PFS and OS durations did not differ between the HDT and SDT arms, with 7-year estimates of PFS of 17% and 16%, respectively, and OS of 37% and 42%, respectively. Of 242 patients achieving at least 75% tumor reduction, no difference was observed in PFS or OS among the 121 patients randomly assigned to IFN and the 121 patients randomly assigned to no maintenance therapy. Among 157 patients relapsing on SDT, 87 received a salvage autotransplantation; their median survival time of 30 months was only slightly better than the survival time of the remaining patients who were managed with further SDT (23 months; P = .13). Conclusion The HDT and SDT regimens used in S9321 yielded comparable response rates and PFS and OS durations. IFN maintenance therapy did not benefit patients who achieved ≥ 75% tumor reduction on either arm.