Outcomes of patients with myelodysplatic syndrome and chronic myelomonocytic leukemia post clofarabine failure

Background: The outcome of patients with myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) post clofarabine is unknown. Methods: We reviewed 109 patients with MDS or CMML with a median age of 67 years, treated with a clofarabine-based chemotherapy as frontline (n = 38) or salvage (n = 71) therapy. A total of 58 (53%) patients received salvage therapy after clofarabine failure: 13 allogeneic stem cell transplant (ASCT), 18 high-dose cytarabine-containing regimen, 10 hypomethylating agents and 17 investigational treatments. Results: Eight patients achieved complete remission (CR) and three had stable disease for an overall response rate of 19%. With a median follow-up of 3 months from clofarabine failure, 12 patients (11%) remained alive, 5 remain in CR, 4 of them after ASCT. The median overall survival post clofarabine failure was 4 months with a 1-year survival rate of 23%. This outcome is predictable, with patients with high-risk disease at the time of clofarabine failure having the worse survival. To date, patients with MDS continue to have a short survival after failure of all available therapies. Ultimately, patients who are candidates for additional treatments should be offered novel approaches. In conclusion, the outcome of patients with MDS and CMML post clofarabine failure is poor. The pattern is similar to patients with MDS post hypomethylating agent failure and predictable using University of Texas M. D. Anderson Cancer Center global scoring system.