Leukine is a recombinant human granulocyte-macrophage colony-stimulating factor produced by DNA technology in a yeast expression system. Leukine stimulates the differentiation, maturation, and mobilization of cells involved in the innate and adaptive immune response to drive pulmonary host defense function. Partner acquired the rights to the approved drug in 2018.

The iLeukPulm study is supported by the U.S. Department of Defense's Joint Program Executive Office for Chemical, Biological, and Nuclear Defense, as part of a $35 million contract for the development and emergency use of Leukine for COVID-19 treatment. The U.S. Food and Drug Administration has approved the trial design and the study is currently enrolling patients at the University of Utah Health with additional sites expected to join in the coming weeks.

Leukine also is held by the U.S. government in the Strategic National Stockpile and available outside of the U.S. through a Named Patient Program administered by Tanner Pharma.