Relapsed or refractory extranodal DLBCL treated with lenalidomide: A single center study

Background: Approximately one third of Diffuse Large B-cell Lymphoma (DLBCL) arise in tissue different from the lymph node and they are usually termed as extranodal DLBCL. Patients (pts.) with relapsed or refractory disease not eligible to high dose chemotherapy and transplantation had a dismal prognosis. The immunomodulatory agent Lenalidomide shows consistent activity with tolerable safety in multiple phase II studies or relapsed/refractory aggressive NHL. On this basis we conducted a single center study to investigate efficacy and safety of Lenalidomide alone in relapsed pts. with heaviling pre-treated extranodal DLBCL. Methods: 31 extranodal stage 3-4 DLBCL pts. (GI tract 13, liver 2, soft tissue 2, bone 6, breast 6, lung 2 cases) 16 male, 15 female, median age 63 years, received a standard dose of oral Lenalidomide , 25 mg/day for 21 days every 28 days as single agent between March 2011 and August 2013 until disease progression or unacceptable toxicities. Results: All pts. were analyzed. Bone marrow was involved in 16 pts. and 8 case presented a bulky disease. All pts. undervent more than 3 previously lines of therapy, and median time from last previous therapy and Lenalidomide treatment was 3 months. Overall response rate was 32% (10 pts.: with 3 CR, 4 PR, 3 SD) with a median time to response of 2.2 months and median duration of response of 16.8 months, not yet reached in pts. with CR. Toxicity was globally mild: although 15 pts. (48.4%) required at least one dose reduction or interruption, most common grade 3-4 adverse events were neutropenia 7 pts.-22.6%, anemia 7 pts.-22.6% and thrombocytopenia 6 pts.-19.4%. Six pts. had grade 3-4 infectious and 4 pts. had thromboembolic events. Conclusions: Lenalidomide as single agent is effective and safe and produced rapid and durable responses in pts. with extranodal DLBCL also in pts. with heavily pre-treated disease.