Efficacy of venetoclax in high risk relapsed mantle cell lymphoma (MCL) - outcomes and mutation profile from venetoclax resistant MCL patients.

Venetoclax is effective in relapsed patients with mantle cell lymphoma (MCL). Mechanisms of resistance to venetoclax in MCL are poorly understood. We describe the clinical outcomes and genomic characteristics of 24 multiply relapsed patients (median of five prior lines of therapy) who received venetoclax-based therapies; 67% had progressed on BTK inhibitors (BTKi) and 54% had blastoid or pleomorphic histology. Median follow up after venetoclax treatment was 17 months. The overall response rate was 50% and complete response (CR) rate was 21%, 16 patients had progressed and 15 died. The median progression free, overall and post venetoclax survival were 8, 13.5 and 7.3 months respectively. Whole-exome sequencing (WES) was performed on samples collected from seven patients (including five pairs; before starting venetoclax and after progression on venetoclax). The SMARCA4 and BCL2 alterations were noted only after progression, while TP53, CDKN2A, KMT2D, CELSR3, CCND1, NOTCH2 and ATM were altered 2-4-fold more frequently after progression. In two patients with serial samples, we demonstrated clonal evolution of novel SMARCA4 and KMT2C/D mutations at progression. Mutation dynamics in venetoclax resistant MCL is demonstrated. Our data indicates that venetoclax resistance in MCL is predominantly associated with non-BCL2 gene mutations. Further studies are ongoing in MCL patients to evaluate the efficacy of venetoclax in combination with other agents and understand the biology of venetoclax resistance in MCL.

Genomic profiles and clinical outcomes of de novo blastoid/pleomorphic MCL are distinct from those of transformed MCL.

Blastoid and pleomorphic mantle cell lymphomas (MCLs) are variants of aggressive histology MCL (AH-MCL). AH-MCL can arise de novo (AH-DN) or transform from prior classic variant MCL (AH-t). This study is the first integrated analysis of clinical and genomic characteristics of AH-MCL. Patient characteristics were collected from diagnosis (AH-DN) and at transformation (AH-t). Survival after initial diagnosis (AH-DN) and after transformation (AH-t) was calculated. Regression tree analysis was performed to evaluate prognostic variables and in univariate and multivariate analyses for survival. Whole-exome sequencing was performed in evaluable biopsy specimens. We identified 183 patients with AH-MCL (108 were AH-DN, and 75 were AH-t; 152 were blastoid, and 31 were pleomorphic). Median survival was 33 months (48 and 14 months for AH-DN and AH-t, respectively; P = .001). Factors associated with inferior survival were age (≥72 years), AH-t category, Ki-67 ≥50% and poor performance status. AH-t had a significantly higher degree of aneuploidy compared with AH-DN. Transformed MCL patients exhibited KMT2B mutations. AH-MCL patients with Ki-67 ≥50% had exclusive mutations in CCND1, NOTCH1, TP53, SPEN, SMARCA4, RANBP2, KMT2C, NOTCH2, NOTCH3, and NSD2 compared with low Ki-67 (<50%). AH-t patients have poor outcomes and distinct genomic profile. This is the first study to report that AH-MCL patients with high Ki-67 (≥50%) exhibit a distinct mutation profile and very poor survival.

Lymphomatous variant of hairy cell leukaemia: a distinctive presentation mimicking low-grade B-cell lymphoma.

AIMS: Hairy cell leukaemia (HCL) is an indolent B-cell neoplasm that primarily involves the peripheral blood, bone marrow, and spleen. Rarely, patients with HCL present with a lymphoma-like clinicopathological picture mimicking other types of low-grade B-cell lymphoma. Distinguishing HCL from other types of lymphoma is essential, given the different treatments and prognoses. We report two cases of the lymphomatous variant of HCL to draw attention to this unusual presentation. METHODS AND RESULTS: Two cases of HCL presented initially as salivary gland and soft tissue masses. Morphologically, the neoplastic cells showed a typical fried-egg or monocytoid appearance with reniform nuclei, and were positive for CD11c, CD20, CD25, CD103, annexin A1, and cyclin D1. Both cases were positive for the BRAF V600E mutation, as shown by pyrosequencing and mutation-specific immunohistochemistry. The diagnosis was challenging in both patients, and one patient experienced 5 years of disease relapse and progression after treatment with multiple lymphoma-type regimens before the final diagnosis of HCL was established and complete remission was achieved following cladribine therapy. CONCLUSIONS: HCL can very rarely present as an extranodal mass. Being aware of this unusual presentation of HCL is essential to avoid diagnostic confusion with other types of low-grade B-cell lymphoma and to facilitate appropriate therapy.

Long term results of a phase 2 study of vincristine sulfate liposome injection (Marqibo(®) ) substituted for non-liposomal vincristine in cyclophosphamide, doxorubicin, vincristine, prednisone with or without rituximab for patients with untreated aggressive non-Hodgkin lymphomas.

Vincristine sulfate liposome injection (VSLI; Marqibo(®) ; M) is active in relapsed and refractory lymphomas, and approved in the United States for relapsed and refractory adult acute lymphocytic leukaemia. We evaluated VSLI (2·0 mg/m(2) without dose cap) substituted for non-liposomal vincristine (VCR) in a cyclophosphamide, doxorubicin, vincristine, prednisone ± ritiximab (CHOP±R) regimen, creating CHMP±R in 72 untreated, aggressive non-Hodgkin lymphoma patients, including 60 with diffuse large B-cell lymphoma (DLBCL). The overall response rate was 96% (69/72) including complete response (CR) in 65 (90%) and unconfirmed CR in 2 (3%). Median progression-free survival (PFS) and overall survival (OS) were not reached at median follow-up of 8 and 10·2 years, respectively. The 5- and 10-year PFS and OS were 75%, 63%, 87%, and 77%, respectively. Despite VSLI exposure of up to 35 mg, the safety profile of CHMP±R was comparable to that reported for CHOP±R. Grade 3 peripheral neuropathy was reported in 2 (3%) patients; there was no reported Grade 3/4 constipation. CHMP±R was highly active, generally well tolerated, and compared favourably to historical trials with R-CHOP in DLBCL. This enhanced activity probably reflects VCR dose intensification, pharmacokinetic optimization, and enhanced delivery afforded by VSLI. A Phase 3 trial of R-CHMP versus R-CHOP in elderly patients with untreated DLBCL is ongoing.