Interest in a class of drugs called JAK inhibitors to manage COVID-19 is building, and with three such therapies already approved for other diseases, the race to repurpose these treatments has kicked off. Incyte’s Jakafi and Eli Lilly’s Olumiant may have mechanism edge over Pfizer’s Xeljanz, according to reporting by Reynald Castañeda, Pharma Writer for the Investigative News team at GlobalData, a leading data and analytics company. Meanwhile, a fourth candidate – Theravance Biopharma’s TD-0903, which is not yet approved – is also in the fray and stands out for its inhaled mode of administration but its efficacy value is nebulous so far.

Castañeda comments: “JAK inhibitors have grabbed the world’s attention given clinical experience showing that the hyperinflammatory process called cytokine storm syndrome, commonly seen in COVID-19 patients, is a turning point in disease severity. Interviewed experts noted that JAK 1/2 inhibitors such as Jakafi and Olumiant may have a clearer link to downregulating interleukin (IL)-6 to ease the cytokine storm compared to JAK 1/3 inhibitors like Xeljanz.”

On 17 April, Incyte announced it would initiate Jakafi in a Phase III trial, while Olumiant was added to the National Institute of Allergy and Infectious Diseases’ Phase III adaptive COVID-19 treatment trial, with initial results expected in June. Xeljanz is in an investigator-led Phase II trial, and on 23 April, Theravance announced it had dosed its first patient in the Phase I safety trial.

Castañeda adds “Jakafi, Olumiant and Xeljanz have the advantage of being oral therapies compared to TD-0903’s inhaled delivery, according to experts I spoke with. Systemic approaches are valuable in allowing uniform therapeutic spread in the lungs and anti-inflammatory effects in other CSS-sensitive parts of the body.”