What happened?

Shares of Humanigen (NASDAQ:HGEN) are rising sharply and are up by 23.7% as of 12:14 p.m. EDT on Monday, after climbing by as much as 35.2% earlier today. Investors are bidding up the biopharmaceutical company following its announcement on Friday that lenzilumab, its experimental COVID-19 treatment, proved successful in treating a severe case of the disease.

So what 

In a press release published on its website on Friday, Humanigen cites the case of a 77-year-old male patient with a medical history of diabetes, coronary artery disease, and severe chronic obstructive pulmonary disease with emphysema, which is an inflammatory lung disease that can cause difficulty breathing. After contracting the SARS-CoV-2 virus that causes COVID-19, this patient was admitted to the ICU, treated with steroids and antibiotics, and put on respiratory isolation. Despite these efforts, though, the patient's condition worsened, his oxygen demand increased, and he developed acute respiratory distress syndrome. 

Man on a ladder drawing an upward-pointing graph on a board

Image source: Getty Images.

After 13 weeks, and following the U.S. Food and Drug Administration's issuance of an emergency use authorization, the patient was treated with lenzilumab. A week after being treated with this medicine, the patient's symptoms improved; 16 days after the treatment, he was released from the hospital on home oxygen. In the press release, Humanigen also mentioned a study that evaluated the efficacy of the drug on COVID-19 patients with severe cases of the disease. According to the healthcare company, the study demonstrated that lenzilumab significantly reduced the risk of mechanical ventilation and death.

Now what

Lenzilumab is undergoing a phase 3 clinical trial that has enrolled patients both in the U.S. and abroad, and Humanigen expects to publish top-line data from this trial in the fourth quarter. Investors are rightfully enthusiastic that this study will produce positive results. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.