IRAK 4 Inhibitor (PF-06650833) in Hospitalized Patients With COVID-19 Pneumonia and Exuberant Inflammation.

"PF-06650833 is an investigational, highly potent and selective, reversible inhibitor of IRAK4. IRAK4 is a serine, threonine kinase that is a key intracellular signaling node downstream of the myddosome-associated Toll-Like Receptors (TLR) 1, 2, 4, 5, 6, 7, 8, 9 and 10, and the interleukin (IL)-1 family receptors (IL-1R, IL-18R and IL-33R) that mediate much of the innate immune signaling.~As an inhibitor of TLR signaling, PF-06650833 targets a different part of the immune system from the Janus kinase (JAK) inhibitors. Given the partial redundancy of innate immune signaling through IRAK4-independent TLR pathways and the lack of direct suppression of T- and B-cell signaling, PF-06650833 is unlikely to lead to exaggerated immunosuppression."

Placebo will match the study drug in dose, formulation, route and frequency.