The coronavirus pandemic has overtaxed an expanded-use system that just wasn't designed to handle the volume of requests it's getting right now for remdesivir, an experimental antiviral treatment from Gilead Sciences (NASDAQ:GILD).

The overwhelming surge in demand has forced the company to stop accepting new requests from individuals with COVID-19 who want to try the treatment.

Hand halting a coronavirus.

Image source: Getty Images.

The FDA can allow the use of an experimental treatment in cases when patients aren't eligible to enter an ongoing clinical trial of the drug in question. But getting permission to try such an unproven treatment is an involved process that requires consent from an informed patient and lots of paperwork from their physician and Gilead Sciences just to get started.

Given that no treatments have yet been proven to be effective against SARS-CoV-2 in proper clinical trials, there's enormous interest in those that appear promising, which remdesivir does.

So Gilead Sciences has been meeting as many of these requests for use of remdesivir as possible, but they have piled up beyond the system's ability to process. For each request, an investigational review board (IRB) needs to review the physician's treatment plan and ensure the patient knows what they're getting into. If the IRB approval on an individual application, it still needs to be reviewed and approved by the FDA before treatment can begin.

In recent weeks, the number of individual requests for permission to use remdesivir has grown so rapidly that Gilead Sciences now expects it will have pivotal trial data in hand -- and possibly an FDA approval for the drug as a COVID-19 treatment -- before the IRB and FDA can work through the current backlog of expanded-use applications. 

In late February, Gilead Sciences began a pair of phase 3 clinical trials in the U.S. to measure the safety and efficacy of remdesivir in adults with COVID-19. There are also trials underway in China's Hubei province that could provide results in April.