A phase I study of the GM-CSF antagonist E21R.

Purpose: E21R is a competitive inhibitor of GM-CSF. This is the initial clinical study to investigate the safety, toxicity and pharmacokinetics of escalating doses of E21R.

Patients And Methods: Cohorts of three patients received doses of 10, 30, 100, 300, 600 and 1000 micro g/kg per day given subcutaneously daily for 10 days.