(V) In a recent study from Dusseldorf, 18 patients with MDS and AML secondary to MDS were treated with Valproic Acid (VPA) alone, and 5 patients received a combination of VPA and ATRA. A favourable response was observed in 44% of the patients treated with VPA alone, with a median response duration of 4 (3-9) months. Four of the five patients who subsequently relapsed were treated with VPA + ATRA, two of them responding again. The Authors hypotize that pre-treatment with VPA might be necessary for a synergistic effect of both drugs.