Prognostic mutational subtyping in de novo diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease defined using a number of well-established molecular subsets. Application of non-negative matrix factorization (NMF) to whole exome sequence data has previously been used to identify six distinct molecular clusters in DLBCL with potential clinical relevance. In this study, we applied NMF-clustering to targeted sequencing data utilizing the FoundationOne Heme® panel from the Phase III GOYA (NCT01287741) and Phase Ib/II CAVALLI studies (NCT02055820) in de novo DLBCL. Biopsy samples, survival outcomes, RNA-Seq and targeted exome-sequencing data were available for 423 patients in GOYA (obinutuzumab [G]-cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP] vs rituximab [R]-CHOP) and 86 patients in CAVALLI (venetoclax+[G/R]-CHOP).

When the NMF algorithm was applied to samples from the GOYA study analyzed using a comprehensive genomic profiling platform, four of the six groups previously reported were observed: MYD88/CD79B, BCL2/EZH2, NOTCH2/TNFAIP3, and no mutations. Mutation profiles, cell-of-origin subset distributions and clinical associations of MYD88/CD79B and BCL2/EZH2 groups were similar to those described in previous NMF studies. In contrast, application of NMF to the CAVALLI study yielded only three; MYD88/CD79B-, BCL2/EZH2-like clusters, and a no mutations group, and there was a trend towards improved outcomes for BCL2/EZH2 over MYD88/CD79B.

This analysis supports the utility of NMF used in conjunction with targeted sequencing platforms for identifying patients with different prognostic subsets. The observed trend for improved overall survival in the BCL2/EZH2 group is consistent with the mechanism of action of venetoclax, suggesting that targeting sequencing and NMF has potential for identifying patients who are more likely to gain benefit from venetoclax therapy.