MAINTENANCE RITUXIMAB IS ASSOCIATED WITH IMPROVED OVERALL SURVIVAL IN MANTLE CELL LYMPHOMA PATIENTS RESPONDING TO INDUCTION THERAPY WITH BENDAMUSTINE + RITUXIMAB (BR)

Ibrutinib plus Bendamustine and Rituximab in Untreated Mantle-Cell Lymphoma

BACKGROUND

Ibrutinib, a Bruton's tyrosine kinase inhibitor, may have clinical benefit when administered in combination with bendamustine and rituximab and followed by rituximab maintenance therapy in older patients with untreated mantle-cell lymphoma.

METHODS

We randomly assigned patients 65 years of age or older to receive ibrutinib (560 mg, administered orally once daily until disease progression or unacceptable toxic effects) or placebo, plus six cycles of bendamustine (90 mg per square meter of body-surface area) and rituximab (375 mg per square meter). Patients with an objective response (complete or partial response) received rituximab maintenance therapy, administered every 8 weeks for up to 12 additional doses. The primary end point was progression-free survival as assessed by the investigators. Overall survival and safety were also assessed.

RESULTS

Among 523 patients, 261 were randomly assigned to receive ibrutinib and 262 to receive placebo. At a median follow-up of 84.7 months, the median progression-free survival was 80.6 months in the ibrutinib group and 52.9 months in the placebo group (hazard ratio for disease progression or death, 0.75; 95% confidence interval, 0.59 to 0.96; P = 0.01). The percentage of patients with a complete response was 65.5% in the ibrutinib group and 57.6% in the placebo group (P = 0.06). Overall survival was similar in the two groups. The incidence of grade 3 or 4 adverse events during treatment was 81.5% in the ibrutinib group and 77.3% in the placebo group.

CONCLUSIONS

Ibrutinib treatment in combination with standard chemoimmunotherapy significantly prolonged progression-free survival. The safety profile of the combined therapy was consistent with the known profiles of the individual drugs. (Funded by Janssen Research and Development and Pharmacyclics; SHINE ClinicalTrials.gov number, NCT01776840.).

Evolving frontline immunochemotherapy for mantle cell lymphoma and the impact on survival outcomes

Because there have been a dvances in frontline treatment for mantle cell lymphoma (MCL) over the last 2 decades, we sought to characterize the changes in frontline treatment patterns and their association with outcomes. Patients with newly diagnosed MCL from September 2002 through June 2015 were enrolled in a prospective cohort study, and clinical characteristics, treatment, and clinical outcomes were compared between patients diagnosed from 2002 to 2009 (Era 1) compared with 2010 to 2015 (Era 2). Patient age, sex, and simplified MCL International Prognostic Index (sMIPI) score were similar between the 2 groups. In patients age 65 years or younger, there was less use of rituximab plus hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (R-Hyper-CVAD) (16.1% vs 8.8%) but more use of rituximab plus maximum-strength cyclophosphamide, doxorubicin, vincristine, and prednisone (R-maxi-CHOP) alternating with rituximab plus high-dose cytarabine (R-HiDAC), also known as the Nordic regimen, and R-CHOP alternating with rituximab plus dexamethasone, high-dose cytarabine, and cisplatin (R-DHAP) (1.1% vs 26.4%) and less use of R-CHOP or R-CHOP-like regimens (64.5% vs 35.2%) but more use of R-bendamustine (0% vs 12.1%) in Era 2 (P < .001). These changes were associated with improved event-free survival (EFS; 5-year EFS, 34.3% vs 50.0%; P = .010) and overall survival (OS; 5-year OS, 68.8% vs 81.6%; P = .017) in Era 2. In patients older than age 65 years, there was less use of R-CHOP or R-CHOP-like therapy (39.0% vs 14.3%) and nonstandard systemic therapy (36.6% vs 13.0%) but more use of R-bendamustine (0% vs 49.4%). These changes were associated with a trend for improved EFS (5-year EFS, 25.4% vs 37.5%; P = .051) in Era 2. The shift from R-CHOP or R-CHOP-like regimens to R-bendamustine was associated with improved EFS (5-year EFS, 25.0% vs 44.6%; P = .008) in Era 2. Results from this prospective cohort study provide critical real-world evidence for improved outcomes with evolving frontline patterns of care in patients with MCL.

Management of Mantle Cell Lymphoma in the Era of Novel Oral Agents

Objectives: To discuss (1) recent and emerging data for pharmacological management of untreated and relapsed/refractory (R/R) mantle cell lymphoma (MCL) with agents approved in the United States, (2) important considerations for toxicity monitoring and management, and (3) preliminary data and ongoing studies for agents in MCL-specific clinical trials. Data Sources: PubMed/MEDLINE, EMBASE, Google Scholar, product labeling, National Comprehensive Cancer Network, American Cancer Society, and ClinicalTrials.gov were searched for studies published between January 1, 2017, and January 31, 2020, and key historical trials. Study Selection and Data Extraction: Relevant studies conducted in humans and selected supporting preclinical data were reviewed. Data Synthesis: MCL is a rare but usually aggressive non-Hodgkin lymphoma that most commonly affects the older population. Traditionally, the treatment of MCL has been determined based on transplant eligibility. Newer data suggest that more tolerable frontline therapy may produce outcomes similar to intensive historical induction regimens, possibly precluding fewer patients from autologous stem cell transplant and producing better long-term outcomes in transplant-ineligible patients. In the R/R setting, novel regimens are improving outcomes and changing the landscape of treatment. Relevance to Patient Care and Clinical Practice: This review summarizes and discusses recent and emerging data for management of newly diagnosed and R/R MCL; key supportive care considerations for agents are also discussed. Conclusions: Recent study results are changing management of MCL. Although these data have complicated the picture of regimen selection, increasingly effective and tolerable therapy and additional anticipated data point to a brighter future for patients with MCL.