Since the early days of the current coronavirus outbreak, Gilead Sciences’ experimental antiviral drug remdesivir has been hailed as a leading hope. That halo has apparently overwhelmed the Big Biotech.
Gilead has temporarily stopped granting patients emergency access to remdesivir under compassionate use due to an “exponential increase” in requests over the last few days, the company said Sunday. Exceptions will be made to pregnant women and children under 18 with severe COVID-19, the disease caused by the novel coronavirus.
The spike of COVID-19 cases in Europe and the U.S. “flooded an emergency treatment access system that was set up for very limited access to investigational medicines and never intended for use in response to a pandemic,” it said.
As the company works to process previously approved requests, it’s devising expanded access programs for widespread treatment use, pivoting away from the current individual patient pathway.
“This approach will both accelerate access to remdesivir for severely ill patients and enable the collection of data from all participating patients,” Gilead said. It added that these programs are under “rapid development” with regulators worldwide, though exact timelines remain unclear.
Remdesivir was originally designed to tackle Ebola by inhibiting an enzyme called RNA polymerase that’s used by many viruses to replicate, though it never succeeded in that indication. In a 2017 Science Translational Medicine study, scientist found the med could also kill SARS and MERS—two other coronaviruses that caused deadly outbreaks in the 21st century—in lab dishes.
The World Health Organization (WHO) has called remdesivir the “most promising” treatment against the new pathogen since early February, when the virus was quickly spreading in China. “There’s only one drug right now that we think may have real efficacy. And that’s remdesivir,” Bruce Aylward, head of WHO’s COVID-19 mission in China, said last month.
Hopes in the drug shot up further after news of the recovery of the first U.S. patient after treatment with it a couple of weeks ago. But perhaps the tipping point for Gilead came after President Donald Trump highlighted the drug—alongside standard malaria drug chloroquine—as promising treatments against the virus during a press conference Thursday.
In a statement on Thursday, the FDA said it had allowed about 250 patients access to remdesivir through the compassionate use program.
Interests in the med are obviously shared across the Pacific. Chinese scientists have already initiated two clinical trials of remdesivir in mild to moderate and severe COVID-19 patients, with early results expected in April. The National Institutes of Health’s National Institute of Allergy and Infectious Diseases is running a study, and Gilead itself is also testing the drug’s anti-COVID-19 effect in two clinical trials.
“Enrollment in clinical trials is the primary way to access remdesivir to generate critical data that inform the appropriate use of this investigational medicine,” Gilead said in its Sunday statement. But it recognized that many severely ill patients won’t be able to get into clinical trials.
Compassionate use provides a pathway for patients to gain access to an investigational drug outside of clinical trials when no alternative effective therapies are available. Under these programs set up by drugmakers, three categories exist, according to the FDA guidelines.
Before the suspension, Gilead’s remdesivir appeared to be offered to individual patients for emergency use. This requires the FDA and drugmaker to review each patient’s case. Now, with “overwhelming demand” amid the quick spread of SARS-CoV-2, Gilead’s apparently turning to expanded access by a large population. It said the new program, once initiated, will have “a similar expected timeframe that any new requests for compassionate use would have been processed.”
Other than remdesivir and chloroquine, researchers and physicians are also looking at other existing drugs to treat COVID-19. These include AbbVie’s HIV combo therapy Kaletra (Aluvia), which just failed a clinical study in China in critically ill patients. Chinese authorities, which have been dealing with the virus longer, are also recommending an influenza med called Arbidol (umifenovir) that’s not approved in Western countries, old antiviral ribavirin and interferon-alpha. And Fujifilm’s flu drug Avigan (favipiravir) has also shown promise in the clinic, according to Chinese officials.
Roche is testing its arthritis drug Actemra’s ability to rein in the potentially deadly inflammatory response called cytokine storm observed in severe COVID-19 patients, just as Sanofi and Regeneron are running clinical trials of their rival IL-6 inhibitor Kevzara in the same setting.