1. Discovery of candidate predictors of response to tazemetostat in diffuse large B-cell lymphoma and follicular lymphoma using NGS technology on CTDNA samples collected pre-treatment.
- Author
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Clawson A., Sausen M., Ho P., Blakemore S., Miao H., Daigle S., McDonald A.A., Morschhauser F., Salles G., Ribrag V., McKay P., Tilly H., Schmitt A., Gerecitano J., Fruchart C., Johnson P., Radford J., Dickinson M.J., Herbaux C., Opat S., Jurczak W., Cartron G., Lamy T., Zinzani P.L., Assouline S., Morin R.D., Wu H., Clawson A., Sausen M., Ho P., Blakemore S., Miao H., Daigle S., McDonald A.A., Morschhauser F., Salles G., Ribrag V., McKay P., Tilly H., Schmitt A., Gerecitano J., Fruchart C., Johnson P., Radford J., Dickinson M.J., Herbaux C., Opat S., Jurczak W., Cartron G., Lamy T., Zinzani P.L., Assouline S., Morin R.D., and Wu H.
- Abstract
Introduction: B-cell malignancies may depend on the histone methyl transferase EZH2 to perpetuate a less differentiated state, with activating mutations of EZH2 being potential oncogenic drivers. Tazemetostat, a potent, selective EZH2 inhibitor, is in Phase 2 clinical development in relapsed or refractory (RR) Non-Hodgkin Lymphoma (NHL). Objective responses were observed in patients with EZH2 mutant or wild type (WT) tumors in the Phase 1 part of the Phase 1/2 study. The ongoing Phase 2 study enrolls patients with mutant or WT EZH2 havingRR Diffuse Large B-Cell Lymphoma (DLBCL) or Follicular Lymphoma (FL) to determine efficacy and safety. The primary endpoint is overall response rate. Here we report results of a molecular analysis of circulating tumor DNA (ctDNA) collected from patient's plasma and associations with preliminary response data, including the discovery of novel candidate molecular predictors of tazemetostat response. Method(s): Archived tumor and/or plasma-derived CTDNA samples were obtained during screening in the Phase 2 trial of tazemetostat in NHL (NCT01897571).Prospectively, archived tumor was analyzed for EZH2 hot spot mutations Y646X, A682G and A692V using the cobas EZH2 Mutation Test (Roche Molecular Systems, in development). Retrospectively, next generation sequencing (NGS) was performed on archived tumor DNA (target coverage of 1,500X) and CTDNA (20,000X for somatic mutations and 5,000X for structural alterations) to identify somatic mutations, amplifications, and translocations in a panel of 62 genes commonly altered in NHL. Best objective overall response (Cheson 2007) on June 01, 2017 was used to generate three groups: responders (CR + PR; n = 43), progressive disease (PD; n = 66), and patients with either stable disease (SD) or unknown (UK) clinical response (n=76). Genetic alterations identified in CTDNA collected pre-dose, at variant allele frequencies greater than 0.5%, and associated with either the responder or PD groups (discovery c
- Published
- 2018