Treatment of patients with low-risk myelodysplastic syndromes using a combination of all-trans retinoic acid, interferon alpha, and granulocyte colony-stimulating factor

Used as single agents, ATRA, G-CSF, and IFN-alpha have shown a moderate ben efit in patients with low-risk MDS, with a response rate of 10%. The aim of the present study was to evaluate the efficacy of a combination of these a gents. The effect on hemoglobin (Hb), platelets, and absolute neutrophil co unt (ANC), as well as on transfusion frequency, was examined in 25 patients with MDS (11 RA, four RARS, eight RAEB, two CMML). The median age was 61 y ears (range 44-81), and the male/female ratio was 14/11. Treatment consiste d of ATRA at 25 mg/m(2)/day p.o. for months 1, 3, 5, 7, 9, and 11, IFN-alph a at 1.5 MIU twice a week s.c. for 52 weeks, and, in patients with initial ANC < 500/mu l, G-CSF at 100-480 mu g daily s.c. according to the degree of ANC. The duration of therapy was scheduled for 12 months. Two patients ach ieved ongoing CR (+19 months; +16 months), one patient with RA after 3 mont hs and one with CMML after 7 months of treatment. In all patients, the mean ANC increased significantly from 1400 +/- 200/mu l before the start of the rapy to 3500 +/- 600/mu l at the end of treatment (p = 0.025). In two patie nts an increase of Hb was observed, and one patient ceased to require trans fusions. In an additional patient with RA and 5q-syndrome, the platelet cou nt normalized following administration of ATRA/IFN-alpha, increasing from 8 9,0001/mu l to 293,000/mu l. The eight RAEB patients were nonresponders. We conclude that therapy with ATRA, IFN alpha, and G-CSF is effective in appr oximately 35% of low-risk MDS patients (in this study: six of 17) and may i nduce complete remission in individual cases.