What happened?

Shares of Humanigen (HGEN) were down by 8.6% as of 12:50 p.m. EST Wednesday, after having fallen by as much as 13% earlier in the trading day. The catalyst for these losses seems to be an update the clinical-stage biopharmaceutical company delivered regarding its phase 3 clinical trial for lenzilumab in patients hospitalized with COVID-19. 

So what

The phase 3 study in question originally started in late April 2020, and its primary endpoint was time to recovery for coronavirus patients. In a regulatory filing submitted Tuesday night, Humanigen said it was changing the primary endpoint to ventilator-free survival through day 28. Time to recovery will now be one of the study's secondary endpoints.

Sheet of paper on a clipboard with the word "coronavirus" written on it.

Image source: Getty Images.

According to healthcare company, "this change in the primary endpoint represents a more meaningful endpoint for patients, health-care providers, and payors given the current standard of care for hospitalized and hypoxic COVID-19 patients." Naturally, Humanigen had to discuss these changes with the U.S. Food and Drug Administration before moving forward. The company also noted that as of Tuesday, more than 500 patients had been enrolled in the study.

Now what

Humanigen has a lot riding on this clinical trial. The company's shares are up by more than 900% in the past 12 months, in parts thanks to its coronavirus-related efforts. And despite the fact that investors are not thrilled with the protocol change, lenzilumab has already shown some success in treating COVID-19 patients. In other words, it might be worth it to keep an eye on Humanigen.