Durable Responses After Lenalidomide Oral Monotherapy in Patients with Relapsed or Refractory (R/R) Aggressive Non-Hodgkin's Lymphoma (a-NHL): Results From An International Phase 2 Study (CC-5013-NHL-003).

Aggressive NHL (a-NHL) comprises a heterogeneous group of B-cell malignancies, each characterized by a unique histology and molecular markers. The most common types are diffuse large B-cell lymphoma (DLBCL), transformed lymphoma (TL), follicular grade III (FL-III), and mantle cell lymphoma (MCL). Although initial therapy can be effective, up to 40% of patients with DLBCL either fail to respond or relapse after initial therapy (Habermann TM et al JCO 2006), and relapses are likely among patients with MCL. For such patients survival outcomes are particularly poor with few effective treatment options available. Lenalidomide (Revlimid^®), an immunomodulatory agent with anti-proliferative as well as apoptotic activity was tested in a pilot study and demonstrated a 35% overall response rate (ORR) with a median duration of response (DR) of 10.4 months (Wiernik et al 2008 EHA. Abst: 764). Based on these encouraging data, we performed a large, international, confirmatory phase 2 study to assess the safety and efficacy of single-agent lenalidomide in patients with relapsed of refractory DLBCL or MCL (CC-5013-NHL-003).

Patients were required to have relapsed or refractory aggressive B-cell NHL after ≥1 prior therapies and have at least one measurable lesion '2 cm. Patients received oral lenalidomide 25 mg once daily on days 1–21 of a 28-day cycle, and continued therapy until disease progression or unacceptable toxicity.

217 patients were enrolled and received lenalidomide with 108 (50%) DLBCL, 57 (26%) MCL, 19 (9%) FL-III, and 33 (15%) TL (Table 1). The median age was 66 yrs (range, 21–87), 97 patients (45%) had intermediate (3) or high (4–5) IPI scores, and the median time from diagnosis was 2.7 yrs (range, 0.04–20.6). Patients had received a median of 3 prior therapies (range, 1–13), and rituximab was included as a part of the prior therapy in 94% (205/217) of patients. The ORR for all 217 patients was 35% (77/217), with 13% (29/217) complete response (CR)/unconfirmed CR (CRu), 22% (48/217) partial response (PR), and 21% (46/217) with stable disease (SD). Responses were observed in all histological types (Table 1). Patients with a prior stem cell transplantation had a 37% ORR (27/73). The ORR was 28% (27/95) in those patients who were refractory to their last therapy, and 33% (38/116) in patients who were rituximab refractory (defined as <6 months response or no response). Median progression-free survival (PFS) for all patients was 3.5 months (95% CI, 2.5, 4.4) and the median DR for the 77 responders was 11.6 months (95% CI, 6.2, not reached [NR]). The primary side effect of lenalidomide was reversible myelosuppression. Grades 3 or 4 neutropenia occurred in 41%, thrombocytopenia in 19%, anemia in 9%, and leucopenia in 7% of patients. Adverse events caused dose reductions or interruptions in 44% (96/217) of patients and led to treatment discontinuation in 22% (48/217).

This international study supports earlier pilot-study results showing that lenalidomide has promising anti-tumor activity in aggressive B-cell NHL, with a predictable and treatable toxicity profile. These data warrant further evaluation of lenalidomide in combination with other regimens in the treatment of each histological subtype, and further exploration of lenalidomide in the maintenance setting.

Witzig:Celgene: Research Funding. Off Label Use: Lenalidomide in relapsed/refractory aggressive NHL. Vose:Celgene: Research Funding. Zinzani:Celgene: Research Funding. Guo:Celgene: Employment, Equity Ownership. Pietronigro:Celgene: Employment, Equity Ownership. Ervin-Haynes:Celgene: Employment. Czuczman:Celgene: Research Funding.