On Mar. 24, 2020, Partner Therapeutics that Leukine (sargramostim, rhu-GM-CSF) is being assessed in the SARPAC trial (sargramostim in patients with acute hypoxic respiratory failure due to COVID-19 – EudraCT #2020-001254-22) at University Hospital Ghent to treat patients with respiratory illness associated with COVID-19. Major medical centers in Germany, Italy and Spain are considering joining the study. The study will evaluate the effect of Leukine on lung function and patient outcomes.

Granulocyte macrophage colony stimulating factor (GM-CSF) is essential for the health of the lungs. Alveolar macrophages, a cell type found in the lungs, are dependent on GM-CSF for differentiation and normal functioning. GM-CSF is an immunomodulator that plays a critical role in host defense against pathogens and maintaining proper functioning  of the immune system.  GM-CSF confers resistance to influenza by enhancing innate immune mechanisms.

In animal studies, GM-CSF reduced morbidity and mortality due to acute respiratory distress syndrome (ARDS) from viral pneumonia. In clinical studies, use of Leukine showed beneficial effects in patients with viral pneumonia. Recent data highlight the importance of understanding the immune status of patients and role of immunomodulating agents like GM-CSF to activate the immune system to help clear virus and reduce the risk of secondary infections.

For the treatment of COVID-19 associated acute hypoxic respiratory failure and ARDS, Leukine will be used in nebulized form for direct inhalation or through intravenous administration for patients already on a respirator. Nebulized Leukine has been studied in phase 2 and phase 3 randomized trials in pulmonary conditions that affect alveolar macrophages, such as aPAP.  IV administration of Leukine has been studied extensively in other conditions and in phase 2 randomized trials in ARDS.

Leukine was initially approved by Immunex in the United States in 1991 and has been approved for use in five clinical indications.  Its safety and tolerability profile are well understood.  In 2018, Leukine was approved for use as a medical countermeasure to treat Acute Radiation Syndrome (ARS) and has been procured for use by the U.S. Strategic National Stockpile. Leukine is distributed outside the U.S. on a named-patient basis through PTx’s designated program manager, Tanner Pharma Group.  The use of Leukine to treat respiratory disorders associated with COVID-19 is investigational and has not been fully evaluated by any regulatory authority.