Preliminary studies of continuous extracorporeal carbamylation in the treatment of sickle cell anemia.

The lack of effective therapy of sickle cell anemia has prompted investigation of a large number of antisickling agents. The most promising drug, cyanate, was found in previous studies to be toxic when given systemically. The present study examined a semiautomated system for extracorporeal treatment with cyanate of the blood of four patients with sickle cell anemia. All patients achieved hemoglobin carbamylation levels greater than 1 mode of cyanate per mode of Hb4, with minimal systemic exposure to cyanate and no serious toxicity. Hematologic response occurred in two patients and possibly a third. Further study will be required to determine the efficacy of continuous extracorporeal carbamylation in the treatment of sickle cell anemia.