Histogen and its partner Amerimmune have reported positive additional data from the Phase I clinical trial of emricasan to treat mild symptomatic Covid-19 patients.

An orally active, pan-caspase inhibitor, emricasan can potentially reduce the activity of enzymes that facilitate inflammation and apoptosis.

Last year, Histogen obtained specific rights to the drug as a part of its merger with Conatus Pharmaceuticals.

The double-blind, randomised, placebo-controlled, single-site Phase I trial evaluated the safety, tolerability and preliminary efficacy of emricasan against symptomatic mild-Covid-19 in an outpatient setting.

It enrolled a total of 13 subjects at a centre in New York City, US, as against the original target of 40 subjects due to the overall decrease in Covid-19 cases in the city.

The participants were categorised in a 1:1 ratio to receive a twice-daily dose of either 25mg emricasan or placebo for 14 days and were followed up for one month.

Several clinical and laboratory measures and patient-reported outcomes were also analysed in the trial using a US Food and Drug Administration tool.

Emricasan was demonstrated to be safe and well-tolerated during the treatment period and at follow-up day 45 versus placebo in the trial, without any serious adverse events noted.

Furthermore, subjects who received emricasan experienced a complete symptom resolution related to mild Covid-19 such as a cough, headache and fatigue on the seventh day, and was maintained through day 45.

Subjects in the placebo arm had either delayed or no symptom resolution for the trial period.

Upon assessment of the laboratory and exploratory biomarkers from the trial subjects, a rise in specific blood immune cell numbers was seen in subjects receiving emricasan.

Subjects in the emricasan arm also demonstrated normalisation of various serum markers linked to higher blood clotting risks usually observed in Covid-19 patients.

A decline and stabilisation in substances that leak from dying cells in the body were noted in the emricasan arm.

Histogen president and CEO Richard Pascoe said: “These additional findings further reinforce that emricasan can potentially be developed as a therapeutic treatment for mild to moderate Covid-19.

“We, along with Amerimmune, are currently developing a Phase II clinical strategy for emricasan as a new therapeutic option for the treatment of Covid-19 in parallel with exploring partnering opportunities for its future development and commercialisation.”

Histogen and Amerimmune partnered last year to develop emricasan for the treatment of Covid-19.

According to the deal, Histogen retains ownership of emricasan and is responsible for all regulatory submissions and maintaining the current patent portfolio of the drug.