Next-Generation Sequencing in Diffuse Large B-Cell Lymphoma Highlights Molecular Divergence and Therapeutic Opportunities: a LYSA Study

Abstract

Purpose: Next-generation sequencing (NGS) has detailed the genomic characterization of diffuse large B-cell lymphoma (DLBCL) by identifying recurrent somatic mutations. We set out to design a clinically feasible NGS panel focusing on genes whose mutations hold potential therapeutic impact. Furthermore, for the first time, we evaluated the prognostic value of these mutations in prospective clinical trials.Experimental Design: A Lymphopanel was designed to identify mutations in 34 genes, selected according to literature and a whole exome sequencing study of relapsed/refractory DLBCL patients. The tumor DNA of 215 patients with CD20þ de novo DLBCL in the prospective, multicenter, and randomized LNH-03B LYSA clinical trials was sequenced to deep, uniform coverage with the Lymphopanel. Cell-of-origin molecular classification was obtained through gene expression profiling with HGU133þ2.0 Affymetrix GeneChip arrays. Results:The Lymphopanel was informative for 96% of patients. A clear depiction of DLBCL subtype molecular heterogeneity was uncovered with the Lymphopanel, confirming that activated B-celllike (ABC), germinal center B-cell like (GCB), and primary mediastinal B-cell lymphoma (PMBL) are frequently affected by mutations in NF-kB, epigenetic, and JAK-STAT pathways, respectively. Novel truncating immunity pathway, ITPKB, MFHAS1, and XPO1 mutations were identified as highly enriched in PMBL. Notably, TNFAIP3 and GNA13 mutations in ABC patients treated with R-CHOP were associated with significantly less favorable prognoses.Conclusions: This study demonstrates the contribution of NGS with a consensus gene panel to personalized therapy in DLBCL, highlighting the molecular heterogeneity of subtypes and identifying somatic mutations with therapeutic and prognostic impact.

Detection and prognostic value of recurrent exportin 1 mutations in tumor and cell-free circulating DNA of patients with classical Hodgkin lymphoma

“…11 We recently detected an unexpected recurrent point mutation of XPO1 (exportin 1, also known as CRM1: chromosome region maintenance 1) located in exon 15 (c.1711G>A), leading to the Glu571Lys (p.E571K) missense substitution in relapsed/refractory (R/R) primary mediastinal large B-cell lymphoma (PMBL) patients included in the LYSA LNH03 trial program. 14,15 PMBL is well known to share several genetic features with cHL, including mutations in SOCS1, 16 STAT6 17 and PTPN.…”

Lymphoma: turning biology into cures

“…While these are not exclusive to ABC, they are significantly more frequent in this subtype than others. 15 Upstream mutations may provide drug resistance to proximally targeting therapeutics, such as ibrutinib or fostamatinib, and require an alternative approach (Fig 1 ). CARD11 mutations do appear to confer resistance to ibrutinib and sostaurin (a protein kinase C inhibitor) in the ABC subtype.…”

“…CARD11 mutations do appear to confer resistance to ibrutinib and sostaurin (a protein kinase C inhibitor) in the ABC subtype. 10,15 However, there is evidence that concomitant MYD88 and CD79B mutations may be more responsive to ibrutinib. In vitro testing predicts that DLBCL with the CD79B mutation will respond favourably to sostaurin.…”

“…In vitro testing predicts that DLBCL with the CD79B mutation will respond favourably to sostaurin. 15 The presence of BCR mutations and concomitant MYD88 mutation may predict response, but are not essential for responses to interruption of BCR signalling. 10 In the ABC phenotype, specific mutations in TNFAIP3 and GNA13 appear to be associated with R-CHOP resistance and may be identified for an alternative approach in future.…”

“…EZH2 , MLL2 and CREBBP have been found to be significantly more often mutated in GCB-DLBCL. 15 A study of 42 ABC and 83 GCB lymphomas found 22% of GCB had EZH2 point mutations; none were present in ABC cells. 16 Like NF-κB in ABC, EZH2 is thought to be pathogenetic in the GCB phenotype, silencing tumour-suppressor and anti-proliferative gene transcription.…”