Efficacy and tolerability of danazol as a treatment for the anaemia of myelofibrosis with myeloid metaplasia: long-term results in 30 patients.

Androgens are considered the treatment of choice for the anaemia of myelofibrosis with myeloid metaplasia (MMM). Good results have been reported in a few patients treated with danazol, a synthetic attenuated androgen. The long-term efficacy and tolerability of danazol as treatment for the anaemia of MMM was evaluated in 30 patients, who received 600 mg/d, with progressive tapering to the minimum effective dose in the responders after 6 months. Complete response (CR) was defined as transfusion cessation with normal Hb and partial response (PR) as an Hb increase >/=1.5 g/dl with transfusion-independent Hb values >10 g/dl maintained for at least 8 weeks. Median follow-up was 20.5 months (range: 3.5-58 months). Response was achieved in 11 patients (37%), including eight CRs and three PRs. Median time to response was 5 months (range: 1-9 months). Four patients stopped responding at 6-24 months, two responders discontinued treatment because of toxicity, and five maintained response at 3.5-42 months. Pretreatment variables associated with response were lack of transfusion requirement (P= 0.001) and higher Hb at treatment start (P= 0.02). Toxicity was usually moderate, leading to treatment withdrawal in only two cases. Danazol is effective and well tolerated in a substantial proportion of MMM patients with anaemia.