Key clinical point: Long-term maintenance with rituximab outperformed interferon alfa in elderly patients with mantle cell lymphoma (MCL) who responded well to initial treatment.
Major finding: At a median follow-up of about 8 years, patients who responded to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) had an overall survival of 9.8 years when assigned to rituximab maintenance, compared with 7.1 years when receiving interferon alfa (P= .0026).
Study details: An update to the randomized, open-label, phase 3 European MCL Elderly trial, involving 316 patients.
Disclosures: The research was supported by a grant from the European Commission, the Lymphoma Research Foundation, Roche Pharmaceuticals, Bayer Schering Pharma, and Schering-Plough. Dr. Kluin-Nelemans did not report having any financial disclosures.
Kluin-Nelemans HC et al. J Clin Oncol. 2019 Dec 5. doi: 10.1200/JCO.19.01294.
This European MCL Network was remarkable in that it did not limit the duration of rituximab maintenance. Interestingly, local policy at some centers restricted maintenance to 2 years, while others allowed the maintenance until progression or significant toxicity as per protocol. At 5 years, 32% of patients were still receiving rituximab maintenance. A landmark analysis comparing patients who stopped rituximab for reasons unrelated to progression or toxicity to patients who continued maintenance according to protocol found that a longer duration of maintenance was associated with a significant difference in progression-free survival (9.5 y vs. 4.5 y). Results were less impressive in patients who had received fludarabine-based induction, largely due to an increase in toxicity. These results cast into question the practice of limiting rituximab maintenance in MCL (trials and standard practice), but unfortunately do not inform how to approach maintenance after bendamustine induction.—Peter Martin, MD