The US Food and Drug Administration (FDA) has declined Humanigen’s request for Emergency Use Authorization (EUA) of its antibody lenzilumab to treat newly hospitalised Covid-19 patients.
A first-in class antibody, lenzilumab binds to and neutralises granulocyte-macrophage colony-stimulating factor (GM-CSF).
GM-CSF is a key cytokine that causes a hyperinflammatory cascade or cytokine storm associated to Covid-19 and other indications.
In its letter, FDA stated that it was not able to conclude the known and potential benefits of lenzilumab that outweigh the known and potential risks of its use as a therapy for Covid-19.
FDA also invited Humanigen to submit additional data once it becomes available.
The firm’s Phase 3 LIVE-AIR study indicates that early intervention with lenzilumab may prevent consequences of a complete-blown cytokine storm in hospitalised patients with Covid-19.
In August, the firm reported that the National Institutes of Health (NIH) advanced the ACTIV-5/BET-B study of its lenzilumab for Covid-19 from a Phase II exploratory trial to a Phase II/III trial.
Humanigen CEO Cameron Durrant said: “We remain committed to bringing lenzilumab to patients hospitalised with Covid-19.
“We believe the ongoing ACTIV-5/BET-B trial, which has been advanced to enrol up to 500 patients, may provide additional safety and efficacy data sufficient to support our efforts to obtain an EUA to treat hospitalised Covid-19 patients.”
The firm has submitted lenzilumab to Medicines and Health Regulatory Agency in the UK for a rolling review towards potential Marketing Authorization.