Continuous Lenalidomide Maintenance Fails to Improve Survival in Myeloma

Continuous maintenance therapy with lenalidomide (Revlimid) did not significantly improve overall survival (OS) in patients with standard-risk, newly diagnosed multiple myeloma, according to the phase III ENDURANCE trial. The study, which enrolled 1,530 patients, compared continuous lenalidomide maintenance to observation after initial induction and stem cell transplant therapy. Results presented at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting indicated no statistically significant difference in OS between the two arms.

While the primary endpoint of improved OS was not met, the trial did reveal some secondary findings. Progression-free survival (PFS) was significantly longer in the continuous lenalidomide maintenance arm compared to the observation arm. However, the benefit in PFS did not translate into an overall survival advantage. The study also noted a higher incidence of adverse events, particularly hematologic toxicities and skin reactions, in the group receiving continuous lenalidomide.

The ENDURANCE trial's findings challenge the established practice of continuous lenalidomide maintenance in this patient population. Prior to this study, continuous maintenance was widely adopted based on earlier data suggesting a PFS benefit. The trial's design aimed to definitively answer whether this strategy improved long-term survival, a critical outcome for patients with multiple myeloma.

Investigators highlighted that while the OS results were disappointing, the data still provides valuable insights into the risk-benefit profile of continuous lenalidomide. Future treatment decisions may need to consider individual patient factors, disease risk stratification, and the potential for increased toxicity when weighing the benefits of extended maintenance therapy against observation. The full results are expected to be published in a peer-reviewed journal.