CHICAGO—A chemotherapy-free combination of lenalidomide plus rituximab shows similar efficacy and a different safety profile to chemotherapy plus rituximab (R-chemo) followed by rituximab maintenance in patients with previously untreated follicular lymphoma (FL).
According to investigators, the multicenter, international phase 3 RELEVANCE trial is the first to evaluate the chemo-free combination against the standard of care, R-chemo with rituximab maintenance.
“These results show that lenalidomide plus rituximab, a novel immunomodulatory approach, is a potential first-line option for patients with FL requiring treatment,” said lead author Nathan H. Fowler, MD, of the University of Texas MD Anderson Cancer Center in Houston.
Dr Fowler presented the results of the study at the 2018 American Society of Clinical Oncology Annual Meeting (Abstract 7500).
The current standard of care in previously untreated symptomatic FL is immunochemotherapy induction followed by rituximab maintenance.
The immunomodulatory agent lenalidomide has complementary mechanisms with rituximab. Phase 2 studies of combined immunotherapy with lenalidomide and rituximab demonstrated 3-year progression-free survival (PFS) of 79%-81% in previously untreated FL, Dr Fowler said.
Phase 3 RELEVANCE trial (NCT01650701)
Investigators evaluated 1,030 previously untreated grade 1-3a FL patients who required therapy.
Patients in the lenalidomide-rituximab group (n=513) received lenalidomide doses of 20 mg per day on days 2 to 22 and 28 for 6 to 12 cycles. Responders continued on therapy at 10 mg per day for a total of 18 cycles.
The rituximab dose was 375 mg/m2 weekly in cycle 1 and day 1 in cycles 2 to 6 and continued in responders for 12 additional cycles.
Patients in the R-chemo arm (n=517) received the investigator’s choice of standard rituximab-CHOP, rituximab-bendamustine, or rituximab-CVP, followed by 12 cycles of rituximab.
Most patients (72%) in the R-chemo arm received R-CHOP.
Baseline characteristics were similar in both groups, Dr Fowler said.
Co-primary endpoints were complete remission/complete remission unconfirmed (CR/Cru) at 120 weeks and PFS.
At a median follow-up of 37.9 months, the superiority for lenalidomide and rituximab over rituximab-chemotherapy was not established.
For the lenalidomide-rituximab patients, the CR/Cru was 48% and 3-year PFS was 77% as compared to 53% and 78%, respectively, for rituximab-chemotherapy patients, as assessed by an independent review committee.
Overall survival was 94% in both groups.
“Important differences in safety profiles were observed between the arms,” Dr Fowler said.
Rituximab-chemotherapy patients had more frequent neutropenia, febrile neutropenia, growth factor usage, nausea, vomiting, neuropathy, and alopecia.
Lenalidomide and rituximab showed more cutaneous reactions, tumor flare, and diarrhea.
Toxicity profiles differed, with higher grade 4 neutropenia (31% vs 8%) and febrile neutropenia (7% vs 2%) with rituximab-chemotherapy compared with lenalidomide-rituximab, respectively.
More patients experienced grade 3/4 cutaneous events (7% vs 1%) with lenalidomide-rituximab.
Second primary malignancies were slightly higher with rituximab-chemotherapy (10%) than with lenalidomide-rituximab (7%). Grade 5 adverse events were 1% in both groups.
About 70% of patients completed treatment in both groups.
“Lenalidomide and rituximab was not superior to rituximab-chemotherapy based on mature CR/Cru at 120 weeks and interim PFS,” Dr Fowler said. “Both treatments showed similar efficacy results. Treatment effects on PFS were consistent across pre-specified subgroups.”
Dr Fowler presented data as of May 31, 2017. Continued follow-up on PFS and OS is ongoing.
The study is sponsored by Celgene Corporation and the Lymphoma Academic Research Organisation (LYSARC).