Rigel Pharmaceuticals has launched a Phase II clinical trial to test the safety of fostamatinib to treat hospitalised Covid-19 patients.

The study is funded by the National Heart, Lung, and Blood Institute (NHLBI), a unit of the US National Institutes of Health (NIH), along with Inova Health System.

Fostamatinib is an oral inhibitor of spleen tyrosine kinase (SYK), which is associated with the intracellular signalling pathways of different immune cells and its inhibition could improve outcomes in Covid-19 patients.

Fostamatinib disodium hexahydrate tablets are approved in the US and Europe for adult chronic immune thrombocytopenia (ITP). The drug is available in the US under the brand name Tavalisse.

Rigel Pharmaceuticals president and CEO Raul Rodriguez said: “Based on our understanding of SYK’s role in the pathogenesis of the virus and fostamatinib’s mechanism of action, we believe expanding our clinical effort into this second trial in Covid-19 related lung injuries is critical.”

The randomised, double-blind, placebo-controlled Phase II trial will be conducted in about 60 patients at the NIH Clinical Center in Bethesda, Maryland, US, and Inova Fairfax Hospital.

It will involve patients who are a five to seven on the eight-point ordinal scale, meaning they need supplemental oxygen through a nasal cannula or non-invasive ventilation, mechanical ventilation or extracorporeal membrane oxygenation.

Oral treatment will be given twice daily for 14 days, with a follow-up period to day 60.

The primary objective is the safety of fostamatinib over placebo and the secondary objective is the early efficacy and clinically relevant disease progression measures.

Meanwhile, fostamatinib is also in a Phase II trial by Imperial College London to assess its efficacy as a potential treatment for Covid-19 pneumonia.

Earlier this month, the National Institutes of Health (NIH) launched two of three Phase III trials to investigate the safety and effectiveness of different blood thinners to treat adults with Covid-19.