Purpose: Standard treatment for relapsed or refractory follicular lymphoma has not been established. Doxorubicin is often given during the initial treatment. The dosage or drugs chosen for salvage therapy are limited by doxorubicin-induced cardiomyopathy.
Experimental design: The R-EPOCT (rituximab with etoposide, vincristine, pirarubicine, cyclophosphamide, and prednisone) regimen, in which less cardiotoxic pirarubicine is used instead of doxorubicin, with granulocyte colony-stimulating factor (G-CSF) was administered to 20 patients with relapsed or refractory follicular lymphoma. The safety (especially cardiotoxicity) and efficacy of this regimen were studied. As markers of cardiotoxicity, serum troponin T and plasma B-type natriuretic peptide (BNP) levels were measured.
Results: Adverse reactions occurred in 14 of the 20 patients and mainly consisted of grade 3/4 hematologic toxicity. In the evaluation of cardiotoxicity, the BNP level was slightly elevated before the treatment in two patients and the BNP level did not significantly increase after R-EPOCT treatment. The troponin T level was undetectable before and after the treatment in all patients. The response rate was 100%, with complete remission in 16 patients (80%). G-CSF administration increased both Fc gamma receptor type I expression on neutrophils and antibody-dependent cellular cytotoxicity activity. There were no significant differences in the levels of Fc gamma receptor type I expression nor antibody-dependent cellular cytotoxicity activity after three or five cycles of the treatment.
Conclusion: We conclude that the combination of R-EPOCT and G-CSF is well tolerated. This regimen was not cardiotoxic. We are planning a randomized trial to compare the efficacy between R-EPOCT and a combination of R-EPOCT with G-CSF.