SAN DIEGO – Maintenance therapy every other month with rituximab significantly prolonged event-free and overall survival after autologous stem cell transplantation among younger patients with mantle cell lymphoma, based on results from a multicenter, randomized, phase 3 trial.
After a median follow-up period of 50 months, 79% of the rituximab maintenance arm remained alive and free of progression, relapse, and severe infection, compared with 61% of the no-maintenance arm (P = .001), said Steven Le Gouill, MD, PhD, at the 2016 meeting of the American Society of Hematology.
Rituximab maintenance improved the chances of event-free survival by about 54% (hazard ratio, 0.46; 95% confidence interval, 0.28 to 0.74; P = .0016), and secondary analyses linked rituximab maintenance to superior 4-year rates of progression-free survival (82% vs. 65%; P = .0005) and overall survival (89% vs. 81%; P = .041).This is the first study linking rituximab maintenance after ASCT to improved survival in younger patients with mantle cell lymphoma, said Dr. Le Gouill of Nantes University Hospital in Nantes, France.
The trial “demonstrates for the first time that rituximab maintenance after ASCT prolongs event-free survival, progression-free survival, and overall survival” in younger patients with treatment-naïve mantle cell lymphoma, Dr. Le Gouill said. The findings confirm rituximab maintenance as “a new standard of care” in younger patients with mantle cell lymphoma, he concluded.
Prior research http://www.nejm.org/doi/full/10.1056/NEJMoa1200920#t=abstract supports maintenance therapy with rituximab rather than interferon alfa for older patients whose mantle cell lymphoma responded to induction with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), noted Dr. Le Gouill. To examine outcomes in younger patients with treatment-naïve mantle cell lymphoma, he and his associates treated 299 individuals aged 65 years and younger (median age, 57 years) with standard induction consisting of 4 courses of rituximab, dexamethasone, high-dose cytarabine, and salt platinum (R-DHAP) every 21 days, followed by conditioning with rituximab plus BiCNU, etoposide, cytarabine, and melphalan (R-BEAM) and ASCT. Patients without at least a partial response to R-DHAP received 4 additional courses of R-CHOP-14 before ASCT. Patients then were randomized either to no maintenance or to infusions of 375 mg R per m2 every 2 months for 3 years.
A total of 53% of patients were mantle cell lymphoma international prognostic index (MIPI) low risk, 27% were intermediate and 19% were high-risk. Rituximab maintenance was associated with a 60% lower risk of progression (HR, 0.4; 95% CI, 0.23 to 0.68; P = .0007) and a 50% lower risk of death (HR, 0.5; 95% CI, 0.25 to 0.98; P = .04).
The French Innovative Leukemia Organisation sponsored the trial. Dr. Le Gouill disclosed ties to Roche, Janssen-Cilag, and Celgene.