Rituximab in combination with CHOP regimen in T-cell angioimmunoblastic lymphoma (AILD-TL) rich in large B cells. Favourable results in four patients

Abstract

6694 Background: B-cell clonal population is detected in 20% to 40% of AILD-TL. Moreover a subgroup of AILD-TL has been shown to display substantial number of CD20+ large B cells. This subgroup shares the poor prognosis of the classical AILD-TL with a 2-year survival of 40% (Lome-Maldonado, Leukemia 2002). We had postulated that this AILD-TL subgroup might benefit from a treatment with anti-CD20 monoclonal antibody (rituximab) combined to the classical CHOP regimen. Methods: We report four cases of untreated AILD-TL rich in large B cells treated with rituximab (375mg/m2 given on day 1 of each cycle) in combination with CHOP (cyclophosphamide, doxorubicine, vincristine, prednisone) chemotherapy (recycling at d21). Patients were planned to receive 8 cycles, if a good response (at least partial response) was observed after 4 cycles. Results: All the patients presented classical characteristics of AILD-TL with generalized lymphadenopathy, poor performance status, elevated LDH. 2 out of 4 patients had a serum M- component. Auto-immune hemolytic anemia occurred in 2 out of 4 patients. Histologic examinations revealed classical features of AILD-TL with more than 25% of large CD20+ cells with LMP-1 positivity in 2 cases. PCR analysis of tumoral lymph node showed a dominant T-cell clone in 2 cases, one of them also with a dominant B-cell clone. The two remaining cases had oligoclonal T-cell populations with polyclonal B-cell repertoire. A complete remission was achieved in 4 cases after 4 cycles and at the end of treatment for the 3 evaluable patients (treatment is still ongoing in one patient). One patient relapsed at 13 months with a low tumor burden and was treated with cyclophosphamide alone. At the present time, all the patients are alive without evolutive disease at 3, 20, 27 and 34 months. Conclusions : These results led us to consider that rituximab adjonction to CHOP could improve the prognosis of AILD-TL rich in large B cells. This combination warrants further evaluation in a larger phase II study. No significant financial relationships to disclose.