(WB) With the coronavirus claiming thousands of lives across the globe, medical experts are throwing any and all medications they can against the disease, including antiviral drugs that — if effective in clinic trials — may turn attention toward Truvada, commonly used as PrEP for HIV prevention.

One medical expert told the Washington Blade if the early promising results for the antiviral Remdesivir hold out in clinical trials, the drug Truvada — a widely used medication against HIV/AIDS — could also work against the coronavirus.

David Hardy, adjunct professor of medicine for the Division of Infectious Diseases at Johns Hopkins University School of Medicine, said if Remdesivir works, Truvada could be shown to be effective because the two drugs are in the same family of medications.

“If Remdesivir works, because it falls into the same class of medication as Truvada, then Truvada may be able to be tried as well,” Hardy said.

Hardy said Remdesivir and Truvada — both developed by Gilead Sciences — work by the same “mechanism of action,” hitting the virus in a susceptible point in the virus’ replication cycle.

“I would wager to say that if the clinical studies that are studying Remdesivir in China and then in the U.S. now show some promise, then there’s gonna be a very quick look at Truvada to see if it works,” Hardy said.

Although Hardy said he’s unaware of any clinical trials underway for Truvada against coronavirus as of last week, he predicted that would change soon if Remdesivir is shown to be effective.

Hardy said there’s a key difference between the drugs: Truvada as a pill can be administrated orally, in contrast to Remdesivir, which requires intravenous injection.

“That can be much more complicated for treating large numbers of people than pills are,” Hardy said.

As reported by NBC News, there’s hope for Remdesivir, an antiviral used to fight Ebola, MERS and SARS, which is still being studied under clinical trials against coronavirus. Based on early tests, the drug “may start working within 24 hours of the first dose” against COVID-19.

According to anecdotal reports, at least two hospitalized patients who received Remdesivir started to improve by the next day. One was a man who traveled to Wuhan, China, where the virus originated, then after coming back to his home in Washington State became the first person in the United States diagnosed with COVID-19. And Chris Kane, 55, was diagnosed with the coronavirus and given the drug during his hospitalization at Providence Regional Medical Center in Everett, Wash.

In both cases, the patients started to improve after taking Remdesivir within one day. 

But with this limited sample, questions remain about whether it was the drug that led to health improvement, or whether these two patients would have gotten better anyway.

The drug’s use against coronavirus is now officially in clinical trials at Providence Regional Medical Center and first results are expected in late April, according to NBC News. The hospital didn’t respond to the Blade’s request for comment and offered limited information to NBC News, citing an inability to discuss the drug before trials are complete.

As scrutiny on Remdesivir’s potential grows, Gilead Sciences announced on Monday in a statement it will eventually expand access to the drug, but — for the time being — suspend acquisition under early compassionate use.

“During this transition period, we are unable to accept new individual compassionate use requests due to an overwhelming demand over the last several days,” the statement says. “We are focused now on processing previously approved requests and anticipate the expanded access programs will initiate in a similar expected timeframe that any new requests for compassionate use would have been processed.”

Another exception Gilead Sciences set for compassionate use requests for Remdesivir was for pregnant women and youth under age 18 with confirmed COVID-19 infection and severe manifestations of the disease.

Remdesivir was among the drugs potentially effective against the coronavirus mentioned by President Trump, who touted the medication at a White House news conference last week.

Hardy warned despite reports HIV medication may be effective against the coronavirus, patients taking the drugs either for prevention or treatment may still be susceptible to COVID-19 and able to transmit it.

“People have misinterpreted when they have read this that HIV drugs work against the coronavirus that this means that they are somehow protected against the coronavirus by virtue of taking HIV drugs, and that is not something that anyone should assume at this point in time,” Hardy said. “We have no idea whether they work against the virus in any great numbers of people who have been taking the medications.”

The HIV drug Truvada is used not only for HIV treatment, but also prevention and in the form PrEP is seen as a key tool to ending the HIV epidemic. Asked by the Blade if HIV drugs are, in fact, proven to be effective in treating the coronavirus, that also would mean they would be effective in prevention, Hardy cautiously replied, “Maybe. Maybe.”

“There’s many, many factors that are involved when we study the same medication for two different infections,” Hardy said. “You know the dose of the medication that may work in HIV may not be enough. So, we don’t know whether or not the dose of medication that works for HIV is going to be the same.”

Medical experts across the board are cautious about raising hopes about potential medications against the coronavirus. For example, Trump’s public mention of drugs tested against the coronavirus without clinical determination they will be effective has inspired criticism from political opponents and from medical professionals. 

After Trump tweeted out the unproven claim a combination of hydroxychloroquine and azithromycin has a “real chance” to fight the coronavirus, there were consequences. According to ProPublica, the tweet triggered a run on the medication, which is needed for individuals suffering from lupus, including an estimated 1.5 million Americans and several who reported not being able to obtain the medication.

Trump’s suggested use of unproven drugs against coronavirus led to a now infamous fiery exchange during a White House briefing between NBC News correspondent Peter Alexander, who asked whether it was giving people “false hope.” Trump then attacked Alexander in response to a subsequent question, and said he should be ashamed of himself.

Dr. Anthony Fauci, director of the National Institutes of Allergy & Infectious Diseases, pushed back against Trump’s untested claim hydroxychloroquine and azithromycin would be effective against coronavirus when asked about it Thursday during the White House Coronavirus Task Force briefing.

“I’m not entirely sure what the president was referring to, but believe it was a report of hydroxychloroquine and azythromicin,” Fauci said. “Many of the things you hear out there are anecdotal reports. They may be true – but the only way to know is randomized trials.”

Medications for several diseases are on the table for potential use against the coronavirus, including drugs used to treat malaria, such as chlorquine, which is considered one of the best hopes to fight the disease. 

For another HIV drug, Kaletra, which is a combination of lopinavir and ritonavir produced by AbbVie, early tests indicated the drug would be effective, but that didn’t bare out in a major clinical trial. 

Early indications Kaletra could be used against coronavirus were tested on an elderly couple from Italy, who were treated in India with the drug and whose test went from positive to negative, as well as a man in Spain. 

The results on the couple tested in India were so promising that India’s Union Health Ministry had been recommending the treatment.

But hopes for Kaletra quickly faded, after a study released last week in the New England Journal of Medicine, according to Reuters.

A test in Chinese patients with severe coronavirus infection found the 99 who received Kaletra fared no better than the 100 who received standard care over the course of 28 days. All of the patients had pneumonia and were treated at Jin Yin-Tan Hospital in Wuhan, the city where the pandemic began.

According to Reuters, test participants who took Kaletra showed small improvements in their health, but “the differences were not statistically significant.” The drug was also shown to have side effects, prompting the treatments to be halted in 13.8 percent of patients.

Kaletra, however, was not tested against a placebo, which is considered the most effective way to assess a treatment.

Despite the lack of placebo and modest gains shown in patients taking Kaletra, Hardy said the trial results are dispositive.

“I do think that the verdict on Kaletra has been made…and it is negative,” Hardy said, “This study is rapidly being circulated in medical circles now.”

Regardless of the medication that ends up working, odds are likely the treatment for coronavirus will be available well before a vaccine. 

Even with clinical trials underway now, health officials have said it would take between 12 to 18 months before a vaccine would be available to the public. In contrast, Hardy estimated a treatment for coronavirus for individuals who are infected would be ready within six to eight weeks.

Hardy said the effectiveness of treatment will ultimately be gauged on whether or not people infected with coronavirus and taking the medication are able to beat a death rate estimated one time at 3.8 percent.

“If that 3.8 percent can be reduced by giving people Remdesivir, then that will actually prove it works in terms of just giving them supportive care like a ventilator and things like that,” Hardy said.

CORRECTION: An earlier version of this article mischaracterized the drug Remdesivir as as HIV medication. The Blade regrets the error.