Poor efficacy and tolerability of R-CHOP in relapsed/refractory chronic lymphocytic leukemia and Richter transformation.

This phase II trial evaluated efficacy and tolerability of R-CHOP for up to 8 courses in Richter transformation (RT) and up to 6 courses in CLL plus autoimmune cytopenia (AIC) or high-risk (HR) features. HR was defined as fludarabine-refractoriness or early relapse (<36 months) after fludarabine-based treatment; 26 patients were included as HR, 19 patients had AIC, and 15 patients had RT. In the HR cohort, overall response rate was 54%, progression-free and overall survival were 9 and 21 months. In AIC patients overall response rate was 74%, progression-free and overall-survival were 10 and 41 months, respectively, and median increase in hemoglobin was 3.4 g/L. RT patients responded in 67%, progression-free was 10 and overall survival 21 months. The most common adverse events were hematologic toxicities in 92%. Severe infections occurred in 28%. Treatment was discontinued early in 45% of all patients mainly as a result of toxicity. This trial shows that R-CHOP has no role in treating complicated CLL. R-CHOP is associated with significant toxicities and fairly low efficacy compared with almost every other CLL-regimen. In RT, it might still be used as an induction therapy before allogeneic stem cell transplantation.