Lenalidomide-rituximab combo improves PFS, OS in MCL
The use of lenalidomide plus rituximab may improve progression-free survival (PFS) and overall survival (OS) rates in patients with mantle cell lymphoma (MCL), according to a study presented at ASH 2017.
“The combination [of] biologic doublet of lenalidomide plus rituximab is feasible, safe, and active as initial and maintenance therapy for MCL patients who were in need of therapy,” said lead author Dr Jia Ruan from the Department of Medicine, Division of Hematology-Oncology at Weill Cornell Medical College in New York, US.
This multicentre, phase II trial evaluated 38 patients with untreated MCL (median age 65 years, 71 percent male) who underwent 12 cycles of lenalidomide (20 mg, 3 weeks on and 1 week off) and 1 cycle of rituximab (375 mg/m2, four times weekly) during the induction phase. Of these, 33 patients underwent the maintenance phase using the same treatment regimen but with a reduced lenalidomide dose (15 mg). Patients were followed-up for a median of 5 years. Mantle Cell Lymphoma International Prognostic Index (MIPI) scores were used to categorize patients into low-, intermediate-, and high-risk groups, while ClonoSEQ technology was used for minimal residual disease (MRD) analysis. [ASH 2017, abstract 154]
The 3-year and 4-year PFS rates were 80.3 percent and 70.6 percent, respectively, while the 3-year and 4-year OS rates were 91.9 and 83 percent, respectively.
At 5 years, overall response rate was 92 percent, where patients achieved a complete response rate of 64 percent and partial response rate of 28 percent. However, two patients discontinued treatment due to tumour flare without progression before tumour response assessment.
Based on the MIPI scores, low- and intermediate-risk patients had significantly better OS rate vs high-risk patients at 3 years (96.0 percent vs 83.3 percent) and 4 years (91.4 percent vs 65.6 percent).
In addition, MRD evaluation results showed that 8 out of 10 patients attained an MRD-negative remission, with two patients opting to discontinue treatment.
“Lenalidomide and rituximab as initial treatment for MCL can achieve high rate of complete responses and MRD negativity with durable remissions beyond 4 years,” said Ruan, who stated that toxicity was not significantly affected by a continuous treatment, particularly in the context of a very close study follow-up.“Further evaluation of [lenalidomide-rituximab] regimen in larger, randomized frontline trials is warranted,” she added.