Diffuse large B-cell lymphoma (DLBCL), the most common form of non-Hodgkin lymphoma, has been categorized based on the cancer cell of origin as either activated B-cell (ABC) DLBCL or germinal center B-cell (GCB) DLBCL. Each subtype is associated with a certain degree of tumor vulnerability and a corresponding response to therapy.
The more that clinicians know about how a patient’s disease develops, the better equipped they are to devise an informed and precise treatment plan. Yet, between 10-20 percent of DLBCL cases are unclassified, providing little guidance for strategic intervention.
To shed light on the unclassified disease subtype and further define the composition of the ABC and GCB subtypes, the Weill Cornell Medicine and NewYork-Presbyterian Hospital Lymphoma Program’s Dr. John P. Leonard took part in an international research initiative led by the National Cancer Institute at the National Institutes of Health, with findings recently published in the New England Journal of Medicine.
Whereas prior studies of genetic subtyping investigated individual mutations, this research was among the first to examine how mutations in multiple genes may relate to disease pathogenesis and therapeutic response.
Researchers used next-generation sequencing technology to analyze nearly 600 DLBCL patient biopsy samples, contributed in part through the Lymphoma Program’s efforts in collaboration with the Alliance for Clinical Trials in Oncology. Based on the co-occurrence of genetic alterations that they observed, the team discovered four new genetic subtypes of DLBCL – MCD, BN2, N1 and EZB – enhancing science’s understanding of the genetic framework of this aggressive cancer.
“These findings will take us one step closer to potentially employing targeted agents as part of treatment for specific DLBCL subtypes,” says Dr. Leonard. “If we can specifically identify these lymphoma types and incorporate new agents that target relevant pathways, we will advance rational clinical trials with the aim to improve outcomes for patients based on the biology of their disease.”
Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma that occurs primarily in older adults. The disease is typically managed in the initial treatment setting with a combination of chemotherapy and immunotherapy, which tends not to be curative and may impart toxic side effects in some patients.
In search of an effective, less toxic treatment option for those afflicted by MCL, Dr. Jia Ruan and colleagues explored an alternative regimen free of conventional chemotherapy – lenalidomide plus rituximab – to be used in the initial treatment setting. Their multi-center phase II clinical trial of the novel biological pairing was the first-ever study of a non-chemotherapy first-line MCL treatment approach.
Thirty-eight MCL patients enrolled in the trial from July 2011 to April 2014. They received lenalidomide on days 1-21 of a 28-day cycle, and rituximab was administered four times per week during the first cycle, then once every other cycle. The first 12-cycle treatment was considered induction, or initial therapy, and was followed by a maintenance phase, in which therapy is provided to prevent relapse. Treatment was continuous until disease progression, and patients had the option to cease therapy after three years if in remission.
At the 2017 American Society of Hematology Annual Meeting, the researchers examined the long-term outcomes of the trial in a 5-year follow-up analysis to reveal that the drug combination shows promise for effective management of MCL, with the majority of trial participants doing well and maintaining good quality of life. About 90 percent of patients responded to the therapy, and over 60 percent remain in remission.
The research team also measured minimal residual disease (MRD) in patients’ blood, the small number of cancer cells that may be left after treatment that have the potential to grow and cause the patient to relapse. In the small subset of patients with available tumor tissues for MRD analysis, about 80 percent of patients were found to be MRD negative, further demonstrating the novel treatment regimen’s activity and feasibility as an additional therapeutic option for people with MCL.
“We are encouraged by the quality and durability of the responses with the biologic doublet of lenalidomide plus rituximab as initial therapy for mantle cell lymphoma,” said Dr. Ruan. “We hope to bring this active combination to larger studies where it can be combined with other agents and compared to conventional chemotherapy.”
The combination of lenalidomide and rituximab may represent a reasonable alternative to chemotherapy for some people with previously untreated follicular lymphoma (FL), according to a study led by Dr. Peter Martin, chief of the Weill Cornell Medicine and NewYork-Presbyterian Hospital (WCM/NYP) Lymphoma Program.
Dr. Martin collaborated with the Lymphoma Program’s Drs. Jia Ruan and John Leonard, along with experts from academic medical centers across the country, to evaluate the non-chemotherapy drug combination in a phase II trial known as CALGB 50803, the results of which were recently published in the Annals of Oncology. The formalized collaboration was made possible by the Alliance for Clinical Trials in Oncology, a cooperative group sponsored by the National Cancer Institute (NCI).
Lenalidomide plus rituximab was administered over twelve 28-day cycles to 65 adults with previously untreated follicular lymphoma. Seventy-two percent of patients achieved a complete response. At five years, the overall survival rate was 100 percent, and 70 percent of patients remained free from disease progression. Rates are comparable with those typically produced by standard chemotherapy.
The study also demonstrated low rates of hematologic toxicity, such as neutropenia (low white blood cell count), lymphopenia (low lymphocyte levels) and thrombocytopenia (low platelet count), but low-grade side effects like fatigue, constipation, diarrhea and rash were commonly reported.
The results of the CALGB 50803 study do not definitively establish whether lenalidomide-rituximab is more or less toxic or more or less effective than a standard chemotherapy regimen; such insights will be clearer following completion of the randomized phase III RELEVANCE trial, which compares lenalidomide-rituximab to chemotherapy plus rituximab.
Optimal use of chemotherapy requires a careful balance of anti-tumor activity with tolerability. WCM/NYP is proud to be a leader in the discovery and development of therapies that are both active against cancer and well tolerated.