Sequential IL-3 and GM-CSF Therapy in Bone Marrow Failure With Long-Term Follow-Up of Responses

Departments of Bioimmunotherapy and BMT, M. D. Anderson Cancer Center, Houston, TX Abstract 743 platelet counts. Six patients (16%) had trilineage responses, and the other four (10.5%) had bilineage (neutrophil and platelet) responses. All platelet responders were treated at doses ≥ 1.2 µg/kg/day, and a total of 10 of 29 (34%) at these dose levels responded. Trilineage responses can be durable, with the longest ongoing at 6.5 years after therapy completion. The most common side effects were low-grade fever, headache, and fatigue. The maximal tolerated dose was IL-3 at 10 µg/kg/day followed by GM-CSF, 5 µg/kg/day. CONCLUSION: Sequential IL-3 followed by GM-CSF effectively raised blood counts in some patients with bone marrow failure at doses that are well tolerated. Trilineage re- sponses occur and may be durable.