Recombinant interferon alpha 2a, thymopentin and low doses of cytosine arabinoside for the treatment of myelodysplastic syndromes: a pilot study

Eighteen patients (pts) with myelodysplastic syndrome (MDS) were treated with thymopentin (TP) (50 mg subcutaneously for 5 days) and recombinant interferon alpha 2a (rIFN alpha 2a) (3 MU/m2 subcutaneously on the sixth day); the courses were delivered every week. Moreover those pts with > or = 10% blasts in the bone marrow were additionally treated with low dose cytosine arabinoside (LDARAc) (20 mg standard dose, subcutaneously, twice a day for seven days every four weeks). Sixteen pts were finally assessable for response. Seven pts (44%) were classified as good responders, 5 (31%) had a PR; the overall response rate (GR+PR) was 75%. Two pts (12.5%) showed stable disease and the 2 remaining (12.5%) had progressive disease. Six pts with an initial moderate anemia never required supportive care before and during the therapy; in contrast to 10 pts who were transfusion-dependent. After six months of therapy 2 pts decreased their transfusional needs by 50% (1 of them did not receive any transfusion over the following six months of therapy); 2 pts needed no packed red cell infusions and 1 pt decreased his transfusional support by 75%. Five pts kept an unchanged supportive care load. The overall median survival was 12.5 months. Therapy was generally well tolerated with acceptable compliance; the most frequently recorded side effects were neutropenia and thrombocytopenia grade 2-3 among the group receiving LDARAc. However no life-threatening infectious episodes or bleeding were observed. TP, rIFN alpha 2a and LDARAc can be safely administered on an outpatient basis to MDS pts and appears to have significant activity.