# Efficacy and safety of long-term treatment with lenalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma

## TL;DR

This study shows that some patients with relapsed/refractory multiple myeloma can benefit long-term from lenalidomide and dexamethasone with manageable side effects.

## Contribution

The study identifies a subset of patients who achieve long-term benefit from lenalidomide and dexamethasone treatment.

## Key findings

- Patients with long-term benefit had a 100% response rate and median treatment duration of 48.1 months.
- Humoral improvement was more common in patients with long-term benefit (79% vs 55%).
- Lower incidence of grade 3–4 neutropenia was observed in patients with long-term benefit.

## Abstract

Data from two randomized pivotal, phase 3 trials evaluating the combination of lenalidomide and dexamethasone in relapsed/refractory multiple myeloma (RRMM) were pooled to characterize the subset of patients who achieved long-term benefit of therapy (progression-free survival ⩾3 years). Patients with long-term benefit of therapy (n=45) had a median duration of treatment of 48.1 months and a response rate of 100%. Humoral improvement (uninvolved immunoglobulin A) was more common in patients with long-term benefit of therapy (79% vs 55% P=0.002). Significant predictors of long-term benefit of therapy in multivariate analysis were age<65 years (P=0.03), β2-microglobulin <2.5 mg/l (P=0.002) and fewer prior therapies (P=0.002). The exposure-adjusted incidence rate (EAIR) of grade 3–4 neutropenia was lower in patients with long-term benefit of therapy (13.9 vs 38.2 per 100 patient-years). The EAIR for invasive second primary malignancy was the same in patients with long-term benefit of therapy and other patients (1.7 per 100 patient-years). These findings indicate that patients with RRMM can experience long-term benefit with lenalidomide and dexamethasone treatment with manageable side effects.