Rituximab, bendamustine and lenalidomide in patients with aggressive B-cell lymphoma not eligible for anthracycline-based therapy or intensive salvage chemotherapy - SAKK 38/08

Molecular classification and therapeutics in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) encompasses a wide variety of disease states that have to date been subgrouped and characterized based on immunohistochemical methods, which provide limited prognostic value to clinicians and no alteration in treatment regimen. The addition of rituximab to CHOP therapy was the last leap forward in terms of treatment, but regimens currently follow a standardized course when disease becomes refractory with no individualization based on genotype. Research groups are tentatively proposing new strategies for categorizing DLBCL based on genetic abnormalities that are frequently found together to better predict disease course following dysregulation of specific pathways and to deliver targeted treatment. Novel algorithms in combination with next-generation sequencing techniques have identified between 4 and 7 subgroups of DLBCL, depending on the research team, with potentially significant and actionable genetic alterations. Various drugs aimed at pathways including BCR signaling, NF-κB dysfunction, and epigenetic regulation have shown promise in their respective groups and may show initial utility as second or third line therapies to patients with recurrent DLBCL. Implementation of subgroups will allow collection of necessary data to determine which groups are significant, which treatments may be indicated, and will provide better insight to clinicians and patients on specific disease course.

IMiDs New and Old

PURPOSE OF REVIEW

IMiDs are a class of biologic agents with immunomodulatory, anti-angiogenic, and direct anti-cancer activities. This review summarizes current data on clinical development and application of IMiDs in non-Hodgkin lymphoma (NHL) subtypes, focusing primarily on lenalidomide, with additional discussion on managing common side effects.

RECENT FINDINGS

Improved upon the prototype thalidomide, the second-generation compound lenalidomide has enhanced immunological and anti-cancer properties with fewer side effects, while next-generation small molecule cereblon/E3 ubiquitin ligase modulator CC-122 is in early clinical studies. Lenalidomide is FDA-approved for treatment of relapsed/refractory mantle cell lymphoma as a single agent, as well as in combination with rituximab for R/R follicular lymphoma and marginal zone lymphoma. In addition, numerous clinical trials of lenalidomide, as single agent, in combination with anti-CD20 antibodies, or in combination with chemoimmunotherapy regimens, have shown promise in aggressive and indolent NHL in both the upfront and relapsed/refractory setting. As clinical trials with lenalidomide continue to find success in both indolent and aggressive lymphomas, IMiDs are poised to be important building blocks for combinatorial strategies with antibodies, chemotherapy, novel target agents, and emerging immunotherapy involving immune checkpoint inhibitors and chimeric antigen receptor T cell (CAR-T) therapy. Delineation of treatment-specific and disease-specific biomarkers is an important research objective to gain insight into potential mechanisms of action, and to guide future clinical development.

Genetic alterations and their clinical implications in DLBCL

Diffuse large B cell lymphoma (DLBCL) is a highly heterogeneous lymphoid neoplasm with variations in gene expression profiles and genetic alterations, which lead to substantial variations in clinical course and response to therapy. The advent of high-throughput genome sequencing platforms, and especially whole-exome sequencing, has helped to define the genetic landscape of DLBCL. In the past 10 years, these studies have identified many genetic alterations in DLBCL, some of which are specific to B cell lymphomas, whereas others can also be observed in other types of cancer. These aberrations result in altered activation of a wide range of signalling pathways and other cellular processes, including those involved in B cell differentiation, B cell receptor signalling, activation of the NF-κB pathway, apoptosis and epigenetic regulation. Further elaboration of the genetics of DLBCL will not only improve our understanding of disease pathogenesis but also provide further insight into disease classification, prognostication and therapeutic targets. In this Review, we describe the current understanding of the prevalence and causes of specific genetic alterations in DLBCL and their role in disease development and progression. We also summarize the available clinical data on therapies designed to target the aberrant pathways driven by these alterations.

CNS relapse in patients with DLBCL treated with lenalidomide plus R-CHOP (R2CHOP): analysis from two phase 2 studies

Central nervous system (CNS) relapse of diffuse large B-cell lymphoma (DLBCL) is a devastating event occurring in ~ 5% of patients treated with R-CHOP. We hypothesized that adding lenalidomide to R-CHOP (R2CHOP) may decrease the risk of CNS relapse. We analyzed records for patients with DLBCL from two R2CHOP trials. We assessed variables pertinent to the CNS-International Prognostic Index (CNS-IPI) scoring system and classified patients into groups of low, intermediate, and high risk of CNS relapse. The 2-year CNS relapse rate for each risk group was estimated using the Kaplan–Meier method and compared with reported rates in cohorts treated with contemporary chemoimmunotherapy. A total of 136 patients were included. Mean age was 65 and median follow-up was 48.2 months. 10.3, 71.3, and 18.4% of patients were classified into low, intermediate, and high-risk CNS-IPI groups, respectively. Only one of 136 patients developed CNS relapse, corresponding to an incidence of 0.7% and an estimated 2-year CNS relapse rate of 0.9% for the entire R2CHOP cohort. The estimated 2-year CNS relapse rates for the low, intermediate, and high-risk groups were 0, 0, and 5.0%, respectively. Frontline therapy with R2CHOP in patients with DLBCL is associated with a lower-than-expected rate of CNS relapse.

Rituximab plus bendamustine as front-line treatment in frail elderly (>70 years) patients with diffuse large B-cell non-Hodgkin lymphoma: a phase II multicenter study of the Fondazione Italiana Linfomi

We conducted a phase II study to assess activity and safety profile of bendamustine and rituximab in elderly patients with untreated diffuse large B-cell lymphoma (DLBCL) who were prospectively defined as frail using a simplified version of the Comprehensive Geriatric Assessment (CGA). Patients had to be over 70 years of age, with histologically confirmed DLBCL. Frail patients were those younger than 80 years with a frail profile at CGA or older than 80 years with an unfit profile. Treatment consisted of 4-6 courses of bendamustine [90 mg/m² days (d)1-2] and rituximab (375 mg/m² d1) administered every 28 days. Other main study end points were complete remission rate and the rate of extra-hematologic adverse events. Forty-nine patients were enrolled of whom 45 were confirmed eligible. Overall, 24 patients achieved a complete remission (53%; 95%CI: 38-68%) and the overall response rate was 62% (95%CI: 47-76%). The most frequent grade 3-4 adverse event was neutropenia (37.8%). Grade 3-4 extra-hematologic adverse events were observed in 7 patients (15.6%; 95%CI: 6.5-29.5%); the most frequent was grade 3 infection in 2 patients. With a median follow up of 33 months (range 1-52), the median progression-free survival was ten months (95%CI: 7-25). The study shows promising activity and manageable toxicity profile of BR combination as first-line therapy for patients with DLBCL who are prospectively defined as frail according to a simplified CGA, as adopted in this trial (clinicaltrials.gov identifier: 01990144).

Venous thromboembolism in patients with non-Hodgkin lymphoma or chronic lymphocytic leukemia treated with lenalidomide: a systematic review

Lenalidomide has been associated with an increased risk of venous thromboembolism (VTE) in multiple myeloma. It is unclear whether patients with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) are also at such risk. We conducted a systematic review of the incidence of VTE in prospective trials of lenalidomide-treated patients with NHL or CLL. Sixty-eight unique reports were assessed for inclusion. For grade ≥3 VTE, 98 events were reported in 3043 patients (60 studies) (crude incidence: 3.22% [95% confidence interval: 2.6-3.9%]). For any grade VTE, 97 events were reported in 2244 patients (46 studies) (crude incidence: 4.32% [3.5-5.2%]). Subgroup analysis showed no difference based on histological subtype or use of prophylaxis. The study is at risk of bias, largely due to insufficient data from the individual studies. Within the limitations of this systematic review, we found a low risk of VTE in patients with NHL treated with lenalidomide.

Efficacy of bendamustine on thrombocytopenia and hemolytic anemia secondary to CD5-positive B-cell lymphoma with massive splenomegaly in a patient with rheumatoid arthritis

Chemotherapy for lymphoma may be avoided in the presence of coincident cytopenia. In case of immune cytopenia secondary to lymphoma, treatment of cytopenia is the same for primary cases, however, chemotherapy for lymphoma may be effective at the cost of severe hematological toxicity. The present study reports a complex case of thrombocytopenia and direct antiglobulin test-negative hemolytic anemia, thus mimicking Evans syndrome, secondary to cluster of differentiation 5-positive B-cell lymphoma with massive splenomegaly, in a patient suffering from rheumatoid arthritis for two decades. Treatment with prednisolone, high-dose dexamethasone, eltrombopag and rituximab for cytopenia were not effective. Chemotherapy with bendamustine subsequently resolved the cytopenia, additionally resulting in a complete remission of lymphoma. Thus, bendamustine may have a role in the management of lymphoma complicated with severe cytopenia.