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CD19-targeted chimeric antigen receptor (CAR) T cell therapy is an effective treatment for diffuse large B cell lymphoma (DLBCL). In addition to cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity (ICANS), B cell aplasia and hypogammaglobulinemia are common toxicities predisposing these patients to infections. We analyzed 60 patients with DLBCL treated with FDA-approved CD19 CAR T cells and report the incidence, risk factors, and management of infections during the first year after treatment. A total of 101 infectious events were observed, including 25 mild, 51 moderate, 23 severe, 1 life-threatening, and 1 fatal infection. Bacteria were the most common causative pathogens. The cumulative incidence of overall, bacterial, severe bacterial, viral, and fungal infection at 1 year were 63.3%, 57.2%, 29.6%, 44.7%, and 4%, respectively. In multivariate analyses, the use of systemic corticosteroids for the management of CRS or ICANS was associated with an increased risk of infections and prolonged admission. Impaired performance status and history of infections within 30 days before CAR T cell therapy was a risk factor for severe bacterial infection. In conclusion, infections were common within the first 60 days after CAR T cell therapy, however, they were not associated with an increased risk of death.

We evaluated the triplet regimen obinutuzumab-atezolizumab-lenalidomide (G-atezo-len) for patients with relapsed/refractory (R/R) follicular lymphoma (FL) in an open-label, multicenter phase Ib/II study (BO29562; NCT02631577). An initial 3 + 3 dose‐escalation phase to define the recommended phase II dose of lenalidomide was followed by an expansion phase with G-atezo-len induction and maintenance. At final analysis, 38 patients (lenalidomide 15 mg, n = 4; 20 mg, n = 34) had completed the trial. Complete response rate for the efficacy population (lenalidomide 20 mg, n = 32) at end-of-induction was 71.9% (66.7% in double‐refractory patients [refractory to rituximab and alkylator] [n = 12]; 50.0% in patients with progressive disease within 24 months of first-line therapy [n = 12]). The 36-month progression-free survival rate was 68.4%. All treated patients had ≥1 adverse event (AE; grade 3–5 AE, 32 patients [84%]; serious AE, 18 patients [47%]; AEs leading to discontinuation of any study drug, 11 patients [29%]). There were 2 fatal AEs (1 merkel carcinoma, 1 sarcomatoid carcinoma; both unrelated to any study drug). The G‐atezo-len regimen is effective and tolerable in patients with R/R FL. AEs were consistent with the known safety profile of the individual drugs.

Activating MYD88 mutations promote pro-survival signaling through BTK and HCK, both targets of ibrutinib. Despite high response rates, complete responses to ibrutinib are lacking, and other MYD88 triggered pro-survival pathways may contribute to primary drug resistance. B-cell receptor (BCR) signaling has been observed in lymphomas driven by mutated MYD88, even without activating the BCR pathway mutations. We identified activated SYK (p-SYK), a component of BCR in complex with MYD88 in MYD88-mutated WM and ABC DLBCL lymphoma cells. Confocal microscopy confirmed co-localization of MYD88 with SYK in MYD88-mutated cells. Knockdown of MYD88 or use of a MYD88 signaling inhibitor abrogated SYK activation, while expression of mutated but not wild-type MYD88 amplified p-SYK in MYD88-mutated and wild-type lymphoma cells. Knockdown of SYK or use of inhibitors targeting SYK blocked p-STAT3 and p-AKT signaling in MYD88-mutated cells. Cell viability analysis showed that combining ibrutinib and SYK inhibitors triggered synthetic killing of MYD88-mutated lymphoma cells. Our findings extend the spectrum of mutated MYD88 pro-survival signaling to include SYK directed BCR cross talk in MYD88-mutated lymphomas. Targeting SYK in combination with ibrutinib produces synthetic lethality, providing a framework for the clinical investigation of ibrutinib with SYK inhibitors in MYD88-mutated lymphomas.

We sought to define the genomic landscape of diffuse large B-cell lymphoma (DLBCL) by using formalin-fixed paraffin-embedded (FFPE) biopsy specimens. We used targeted sequencing of genes altered in hematologic malignancies, including DNA coding sequence for 405 genes, noncoding sequence for 31 genes, and RNA coding sequence for 265 genes (FoundationOne-Heme). Short variants, rearrangements, and copy number alterations were determined. We studied 198 samples (114 de novo, 58 previously treated, and 26 large-cell transformation from follicular lymphoma). Median number of GAs per case was 6, with 97% of patients harboring at least one alteration. Recurrent GAs were detected in genes with established roles in DLBCL pathogenesis (e.g. MYD88, CREBBP, CD79B, EZH2), as well as notable differences compared to prior studies such as inactivating mutations in TET2 (5%). Less common GAs identified potential targets for approved or investigational therapies, including BRAF, CD274 (PD-L1), IDH2, and JAK1/2. TP53 mutations were more frequently observed in relapsed/refractory DLBCL, and predicted for lack of response to first-line chemotherapy, identifying a subset of patients that could be prioritized for novel therapies. Overall, 90% (n = 169) of the patients harbored a GA which could be explored for therapeutic intervention, with 54% (n = 107) harboring more than one putative target., Key points This study demonstrates the applicability of CLIA-compliant targeted FFPE sequencing for large-scale clinical trials.TP53mut is the main predictor of refractoriness or early relapse.