Danazol Treatment in Lower Risk MDS Patient with Severe Thrombocytopenia: A Monocentric Experience

Background:

Severe thrombocytopenia is an uncommon event in lower risk MDS patients, but it may significantly influence the prognosis. In fact, when it occurs, major bleeding may be a life-threatening complication. No licensed pharmacologic approach is nowadays available yet for these patients. Eltrombopag seems to be a very interesting product, but its efficacy and safeness are still to be better demonstrated. Romiplostim could be suitable too, but, at present, its safety is uncertain in MDS patients. Also danazol, an attenuated androgen, seems to have some ability to increase the platelet count in this context.

Patients and methods:

We retrospectively reviewed 17 thrombocytopenic patients affected by MDS, treated with danazol and observed for at least 6 months. Three patients of these had a therapy-related MDS. At the starting time of danazol therapy, the IPSS was “low” or “intermediate-1” in 16 cases; “intermediate-2” in 1 case. The IPSS-R was “very low”, “low” or “intermediate” in 16 cases; “very high” in 1 case. In 14 patients the platelet count was lower than 25x10⁹/L, in the other 3 lower than 40x10⁹/L, but with spontaneous bleeding. The initial dose was 600 mg/day for all the patients. The IWG criteria of response (Cheson 2006) were adopted. The outcomes were observed after 3 and 6 months from the beginning of therapy. Only descriptive statistical analysis was used.

Results:

At the beginning of therapy, the average platelet count of the 17 patients was 22.6 x10⁹/L (S.D. 8.8, range 6-38). After 3 months, the therapy with danazol was ongoing in 16 patients (in 1 case the drug was discontinued due to renal failure). Platelet improvement, according to IWG criteria, was observed in 8 cases (47%). The average platelet count was 45.3x10⁹/L (S.D. 32.9, range 4-133). The only one “high risk” patient did not show response. After 6 months danazol was still ongoing in 11 patients (in 5 cases the drug was stopped for inefficacy). The response according to IWG criteria was evident in 9 patients (52% of the initial 17 patients). The average platelet count was 66x10⁹/L (S.D. 63.9, range 11-218). Adverse events recorded were as follows: increase in transaminases in 3 cases (in 2 of these the dose was reduced to 400 mg/day); severe but reversible renal failure in 1 case (the drug was stopped); moderate increasing of serum creatinine in 1 case (the drug was reduced to 400 mg/day); reversible cutaneous rush (the drug was reduced to 400mg/day); amenorrhea in 1 case (the only fertile woman in the series); weight loss and loss of appetite in 1 case, weight gain in 1 case.

Conclusions

This series confirms the efficacy of danazol to improve platelet count in approximately half of patients with severe thrombocytopenia due to “low-risk” MDS. In all patients with increased platelet count, the response was clinically significant. The response may not be immediate. Actually, there was an improvement of platelet count even after three months of therapy. The toxicity profile of this drug is low. The mechanism of action of danazol in MDS patients remains unclear. Waiting for more information on the efficacy and safety of eltrombopag from the clinical trials in progress, danazol may be a good therapeutic option for these patients.