Efficacy of Venetoclax and Dexamethasone in Refractory IgM Primary Plasma Cell Leukemia with t(11;14) and TP53 Mutation: A Case Report and Literature Review

Venetoclax in the treatment of secondary plasma cell leukemia with translocation t(11;14): a case report and literature review

Introduction

Venetoclax is a BCL-2 inhibitor with proven efficacy in patients with multiple myeloma (MM) and translocation t(11;14). However, its role in plasma cell leukemia (PCL) remains unclear. Herein, we aimed to report a case of relapsed MM with secondary PCL and t(11;14) achieving complete (CR) and durable remission with venetoclax therapy.

Case presentation

A 52-year-old gentleman was diagnosed with MM-free light chain lambda (ISS III) in December 2016. He received induction therapy, followed by autologous stem cell transplant. (ASCT) in May 2017 and maintenance. A year later, the patient relapsed with secondary PCL. His cytogenetics analysis revealed t(11; 14). The patient failed salvage chemotherapy and was shifted to venetoclax with dexamethasone treatment. The patient attained complete remission (CR), which was maintained for two years and a half before he developed fatal COVID-19 pneumonia.

Conclusion

In comparison with the reported literature, this case report offers the latest compilation of the available evidence on the use of venetoclax in patients with PCL. Furthermore, our patient achieved CR for the longest reported durable response in literature thus far. Prospective clinical trials are needed to elucidate the optimal dosage, combination, and duration of treatment, ensuring better representation and generalizability of the findings. Meanwhile, venetoclax may be considered as a therapeutic option in patients with PCL t(11;14).

Clinical experiences with venetoclax and other pro-apoptotic agents in lymphoid malignancies: lessons from monotherapy and chemotherapy combination

BH3-mimetics are a novel drug class of small molecule inhibitors of BCL2 family proteins which restore apoptosis in malignant cells. The only currently approved BH3-mimetic, the selective BCL2 inhibitor venetoclax, is highly efficacious in chronic lymphocytic leukemia and has rapidly advanced to an approved standard of care in frontline and relapsed disease in combination with anti-CD20 monoclonal antibodies. In this context, tumour lysis syndrome and myelosuppression are the most commonly encountered toxicities and are readily manageable with established protocols. Venetoclax is active in other lymphoid malignancies including several B cell non-Hodgkin lymphomas, acute lymphoblastic leukemia and multiple myeloma, with the highest intrinsic sensitivity observed in mantle cell lymphoma and Waldenstrom macroglobulinemia. Venetoclax combination with standard regimens in follicular lymphoma, multiple myeloma and aggressive B cell neoplasms has shown some promise, but further studies are required to optimize dose and scheduling to mitigate increased myelosuppression and infection risk, and to find validated biomarkers of venetoclax sensitivity. Future research will focus on overcoming venetoclax resistance, targeting other BCL2 family members and the rational design of synergistic combinations.

Novel Approaches Outside the Setting of Immunotherapy for the Treatment of Multiple Myeloma: The Case of Melflufen, Venetoclax, and Selinexor

Although the survival rate of patients with multiple myeloma has significantly improved in the last years thanks to the introduction of various classes of new drugs, such as proteasome inhibitors, immunomodulatory agents, and monoclonal antibodies, the vast majority of these subjects relapse with a more aggressive disease due to the acquisition of further genetic alterations that may cause resistance to current salvage therapies. The treatment of these often "triple" (or even more) refractory patients remains challenging, and alternative approaches are required to overcome the onset of that resistance. Immunotherapies with novel monoclonal, drug-conjugated, or bi-specific antibodies, as well as the use of chimeric antigen receptor T cells, have been recently developed and are currently investigated. However, other non-immunologic therapeutic regimens based on melfluflen, venetoclax, or selinexor, three molecules with new mechanisms of action, have also shown promising results in the setting of relapsed/refractory myeloma. Here we report the most recent literature data regarding these three drugs, focusing on their efficacy and safety in multiple myeloma.

Transcriptomic Analysis in Multiple Myeloma and Primary Plasma Cell Leukemia with t(11;14) Reveals Different Expression Patterns with Biological Implications in Venetoclax Sensitivity

Simple Summary

The growing interest in BCL2 inhibitors for the treatment of multiple myeloma (MM) has led to the need for biomarkers that are able to predict patient’s sensitivity to the drug. The presence of the chromosomal translocation t(11;14) in MM is mainly associated with sensitivity to venetoclax and good prognosis. The incidence of t(11;14) largely increases in primary Plasma Cell Leukemia (pPCL) in association with an unfavorable outcome. Currently, data concerning pPCL sensitivity to venetoclax are virtually absent. In this context, we investigated the transcriptome of MM and pPCL with t(11;14), evidencing that the two clinical entities are likely responsive to venetoclax based on different molecular programs, thus prompting further studies to elucidate better novel potential predictive biomarkers.

Abstract

Mechanisms underlying the pathophysiology of primary Plasma Cell Leukemia (pPCL) and intramedullary multiple myeloma (MM) need to be further elucidated, being potentially relevant for improving therapeutic approaches. In such a context, the MM and pPCL subgroups characterized by t(11;14) deserve a focused investigation, as the presence of the translocation is mainly associated with sensitivity to venetoclax. Herein, we investigated a proprietary cohort of MM and pPCL patients, focusing on the transcriptional signature of samples carrying t(11;14), whose incidence increases in pPCL in association with an unfavorable outcome. In addition, we evaluated the expression levels of the BCL2-gene family members and of a panel of B-cell genes recently reported to be associated with sensitivity to venetoclax in MM. Moreover, transcriptional analysis of lncRNAs in the two clinical settings led to the identification of several differentially expressed transcripts, among which the SNGH6 deregulated lncRNA might be relevant in the pathogenesis and prognosis of pPCL with t(11;14). Overall, our data suggest that MMs and pPCLs with t(11;14) might be responsive to venetoclax based on different molecular programs, prompting further studies to elucidate better novel potential predictive biomarkers.