Prospective subgroup analyses of the randomized MCL‐002 (SPRINT) study: lenalidomide versus investigator's choice in relapsed or refractory mantle cell lymphoma

In the mantle cell lymphoma (MCL)‐002 study, lenalidomide demonstrated significantly improved median progression‐free survival (PFS) compared with investigator's choice (IC) in patients with relapsed/refractory MCL. Here we present the long‐term follow‐up data and results of preplanned subgroup exploratory analyses from MCL‐002 to evaluate the potential impact of demographic factors, baseline clinical characteristics and prior therapies on PFS. In MCL‐002, patients with relapsed/refractory MCL were randomized 2:1 to receive lenalidomide (25 mg/day orally on days 1–21; 28‐day cycles) or single‐agent IC therapy (rituximab, gemcitabine, fludarabine, chlorambucil or cytarabine). The intent‐to‐treat population comprised 254 patients (lenalidomide, n = 170; IC, n = 84). Subgroup analyses of PFS favoured lenalidomide over IC across most characteristics, including risk factors, such as high MCL International Prognostic Index score, age ≥65 years, high lactate dehydrogenase (LDH), stage III/IV disease, high tumour burden, and refractoriness to last prior therapy. By multivariate Cox regression analysis, factors associated with significantly longer PFS (other than lenalidomide treatment) included normal LDH levels (P < 0·001), nonbulky disease (P = 0·045), <3 prior antilymphoma treatments (P = 0·005), and ≥6 months since last prior treatment (P = 0·032). Overall, lenalidomide improved PFS versus single‐agent IC therapy in patients with relapsed/refractory MCL, irrespective of many demographic factors, disease characteristics and prior treatment history.