Safety and Efficacy of Bendamustine with or without Rituximab for the Treatment of Heavily Pretreated CLL and Lymphoma Patients. A Multicenter Retrospective Study.

Bendamustine is an alkylating agent with a nitrogen mustard group and a purine like benzimidazol group. Recently this drug was introduced in Italy. We analized all pts treated in sixteen haematological Italian centers with Bendamustine alone or in combination with anti-CD20 antibody.

On an intention to treat basis pts who have received at least one complete cycle were evaluable for response and toxicity. The treatments consisted of: Bendamustine 60-90 mg/m2 days 1,2 alone or in combination with Rituximab 375 mg/m2 day 0, every 21 or 28 days. 173 pts were analized, median age was 67 (range 31-87), 114 were male, 63 chronic lymphatic leukaemia 41 indolent non-follicular lymphoma, 26 diffuse large B cell lymphoma, 26 follicular lymphoma, 15 mantle cell lymphoma, 2 Peripheral T cell lymphoma. Pts were heavily pretreated, the median number of previous treatments was 3,5 (range 1-8), 121 pts have experienced more than three chemotherapy schemes. One hundred and twenty-seven pts were previously treated with Rituximab and 24 performed an autologous peripheral blood stem cell transplantation. The Bendamustine pre-treatment condition was: 70 relapsed pts, 40 with refractory disease and 63 with a progressive disease after partial response. The median number of Bendamustine cycles was 4.3 (range 1-11).

All patients were evaluable for response: 48 pts (28%) obtained a complete remission, 78 (45%) a partial response or stable disease with an overall response rate of 73% and 47 were non responders. According to histotype we observed that 10/15 pts (67%) with mantle cell lymphoma obtained a response (6 CR;4 PR), 37/41 (9 CR; 28 PR) indolent non follicular lymphoma and 25/26 (96%) follicular lymphoma obtained a response (12 CR;13 PR), 46/63 CLL obtained a response and 8/26 (31%) DLBCL obtained a response to therapy (4 CR;4 PR), none of the two T lymphoma pts responded to therapy. With a median period of observation of 12 months (1-46) 121 (70%) pts are alive and 83 pts are in complete remission or with stable disease without any other treatment. The overall survival was 82%, 72%, 68% and 27% respectively for indolent, CLL, mantle cell and diffuse large B cell lymphoma. The progression free survival was 31%, 27%, 15% and 10% respectively for indolent, CLL, mantle cell and diffuse large B cell lymphoma. Fifthy-two pts died, 47 for progressive disease, 11 due to infection and sepsis (6%) and 2 due to other causes not related with therapy or disease. In this group of heavily pretreated pts 760 cycles were performed. The extrahematological toxicity was mild the most important problem were infections (Herpes Zooster, pneumonia, enteritis) reported in 16 pts, hepatic in 4 and cardiologic in 2 pts. The hematological toxicity was trombocytopenia grade 3-4 in 20 pts (12%), neutropenia grade 3-4 in 40 pts (23%) and anemia grade 3-4 in 19 pts (11%).

In conclusion this retrospective study shows that treatment with Bendamustine alone or in combination with Rituximab is a safe and efficacy regimen in a subset of pluriresistent patients. This data shows also that the best results could be obtained in indolent lymphoma and CLL incouraging data in mantle cell lymphoma are reported.

No relevant conflicts of interest to declare.