SUCCESSFUL TREATMENT OF DIAMOND-BLACKFAN ANEMIA WITH INTERLEUKIN-3

This report describes the response of 18 Diamond-Blackfan anemia (DBA) patients to recombinant human interleukin 3 (rhIL-3). rhIL-3 was admi nistered s.c. once daily on an escalating dose schedule (0.5-10 mug/kg /day). The rhIL-3 dose was escalated every 21 days until erythroid res ponse was attained, grade III or IV nonhematologic toxicity was observ ed, or the maximal rhIL-3 dose was reached. Four patients experienced clinically significant erythroid responses. Two of the responders were steroid-dependent and transfusion-independent, while two were steroid -independent and transfusion-dependent. Baseline clinical or laborator y parameters, in particular in vitro bone marrow erythroid progenitor assays, were not useful in predicting rhIL-3 response. Two of the resp onding patients remain on maintenance rhIL-3 without diminution of eff ect at 490 and 855+ days. rhIL-3 was discontinued in the other two res ponders because of the development of deep venous thrombi.