Thalidomide plus prednisone with or without danazol therapy in myelofibrosis: a retrospective analysis of incidence and durability of anemia response.

Low-dose thalidomide and prednisone alone or combined are effective therapies in some persons with primary myelofibrosis (PMF) and anemia with or with RBC transfusion dependence. Danazol is also effective in some persons with PMF and anemia. Responses to these drugs are typically incomplete and not sustained. It is unclear whether adding danazol to thalidomide and prednisone would improve efficacy. We retrospectively compared the outcomes of 88 subjects with PMF and anemia receiving thalidomide and prednisone without (n = 46) or with danazol (n = 42). The primary end point was anemia response, which was 71% (95% confidence interval (CI), 57, 85%) in subjects receiving thalidomide/prednisone/danazol compared with 46% (32, 60%; P = 0.014) in those receiving thalidomide/prednisone. Response rates in subjects who were RBC transfusion dependent was also higher in the danazol cohort (61% (38, 84%)) vs. 25% (6, 44%); P = 0.024). Time to response was rapid (median, 2 months (range, 1-11 months)) and similar between the cohorts. Response duration was longer in the thalidomide/prednisone/danazol cohort (HR 2.18 (1.18-5.42); P = 0.019). Adverse effects were mild and similar between the cohorts. In conclusion, thalidomide/prednisone/danazol seems superior to thalidomide/prednisone in persons with PMF and anemia. Our conclusion requires confirmation in a randomized trial.