Ansun Pharmaceuticals Takes Aim at COVID-19 with Experimental Influenza Treatment

 

San Diego-based Ansun Pharmaceuticals used its influenza research data to dive into attempts to develop a treatment for COVID-19 using an investigational nebulized enzyme asset as a potential treatment for severely infected patients.

Ansun’s investigational recombinant sialidase drug DAS181 is a fusion protein that cleaves sialidic receptors. A number of viruses use sialic acid as a receptor for infecting the epithelial cells. The hope for DAS181 is that it will block the virus from entering those cells and spreading across the body. The medication is being assessed in two clinical trials, a Phase III trial for the treatment of hospitalized, immunocompromised patients with lower respiratory tract parainfluenza virus infections, as well as a Phase IIb trial for the treatment of severe hospitalized influenza infections. Like so many other experimental medications, it has been aimed at COVID-19 patients and some of the anecdotal evidence seen in patients has been highly encouraging. Stanley Lewis, the company’s chief medical officer, told BioSpace in an interview that the drug, which had shown some promise against Middle Eastern Respiratory Syndrome (MERS) a distant cousin to the novel coronavirus, was first tested on two patients in Wuhan, China, the site of the original outbreak of COVID-19.

“We wanted to be part of the solution to COVID,” Lewis said.

The drug was tested in two patients who were classified as severe but had not been placed on a ventilator. Lewis said it was likely that the patients were headed toward acute respiratory distress syndrome. DAS181 was administered to the patients and they recovered. Lewis clarified that the two patients recovered clinically and cleared bilateral pneumonia scans, which he called a remarkable turnaround. Two more patients were treated with DAS181 and both cleared their infections as well, Lewis said. DAS181 is delivered in a nebulized formulation using the Aerogen Solo aerosol drug delivery technology.

“The initial data were highly encouraging and supported a broader investigation into the potential clinical utility of DAS181 to treat patients with severe COVID-19,” Lewis told BioSpace. He added that inhibition of the virus’ entry into the epithelial cells “can really truncate the infection.”

Encouraged by the results in China, Ansun went to the U.S. Food and Drug Administration to talk about running a clinical trial for DAS181 in COVID-19. To the company’s surprise, the regulatory agency greenlit a trial as an add-on to the Phase III STOP PIV trial for lower respiratory tract parainfluenza virus infections. The Phase III trial had been set up to be flexible, which allowed them the leeway to expand the trial, Lewis explained.

In the COVID arm of the trial, Lewis said Ansun will look at patients who are later in the disease state, particularly those who require oxygen supplementation. Lewis said they want to prevent those patients from progressing to the ICU in order to preserve the vital resource of the ventilators. Lewis and Ansun hope that the results they saw in China will be replicated in the clinical trial. The first patients were dosed near the end of April and Lewis said they hope to have their first look at data from that dosing by the end of May. If that data is promising, Lewis said Ansun will likely expand the COVID-19 arm of the trial and enroll more patients in the U.S. and Europe.

Word has spread of the results in China as Lewis said Ansun has received some requests for compassionate use of DAS181, but he noted that the FDA “frowns upon” the use of the drug in that manner. He said even if the patients who use the drug under compassionate use get better, researchers no not learn much from the results.

While the study of DAS181 has been expanded into COVID-19, Lewis said the pandemic has had its own impact on the study of the drug. Ansun had expected interim Phase III analysis in lower respiratory tract parainfluenza virus infections by the end of the year, but that has been delayed by about six months due to the slowdown in work caused by the virus. DAS181 has received both Fast Track and Breakthrough Therapy Designation from the FDA.