Rituximab-Lenalidomide Consolidation Does Not Improve PFS in MCL

Mitchell Smith, MD, PhD, chief medical officer of the Follicular Lymphoma Foundation in Washington, DC, discusses the updated results of the phase 2 ECOG-ACRIN E1411 trial (NCT01415752) of patients with previously untreated mantle cell lymphoma (MCL).

The randomized multi-arm phase 2 trial investigated the frontline combination of rituximab (Rituxan) plus bendamustine (BR) induction followed by consolidation with rituximab plus lenalidomide (Revlimid) in older patients with MCL. Investigators previously reported that the addition of bortezomib (Velcade) in an arm of the trial showed no benefit to progression-free survival (PFS), Smith says.

With longer PFS follow-up of 5.8 years, investigators assessed the efficacy of the consolidation with the addition of lenalidomide. The estimated PFS at 2 years was 85.8% for those who received lenalidomide-rituximab consolidation (95% CI, 78.6%-90.7%) versus 77.7% for those who received only rituximab (95% CI, 69.5%-84.0%). The hazard ratio for lenalidomide-rituximab versus rituximab was 0.96 (80% CI, 0.75-1.23), which was not statistically superior. In study arms where patients did not receive bortezomib, the median PFS in patients who received lenalidomide-rituximab was 7.8 years versus 6.0 years in patients who received rituximab consolidation.

According to Smith, this trial has paved the way for ongoing trials. Notably, the PFS was approximately 6 years across the groups, which was higher overall than historical data would suggest for patients receiving BR in MCL, showing the efficacy of this backbone.

TRANSCRIPTION:

0:08 | We reported about a year and a half ago at ASCO [American Society of Clinical Oncology Annual Meeting], the induction that the addition of bortezomib to BR induction did not significantly benefit the PFS. Now, we've got longer follow-up and we can assess the benefit or not of consolidation with the lenalidomide in addition to the rituximab. And the answer, a bit unfortunate, is that the lenalidomide did not add significantly either, nor did adding both. [This] large study was certainly the first United States-Canadian cooperative group study in MCL, and so we're glad that it was successful. It's paved the way for ongoing trials.

0:56 | What's also interesting is that the basic treatment—the BR with the rituximab consolidation—actually did quite well, much better than historical evaluation with BR. So the median PFS in all of the groups was well over 5 years, close to 6 years. So I think that's encouraging. When I started in MCL, we used to say survival might be 4, 5, or 6 years and now you got first treatment, giving that length of PFS. So that's encouraging, and it served as a basis to build further trials.