There are no approved treatments for monkeypox, but a drug invented at UC San Diego shows promise

Posted at 7:31 PM, Aug 12, 2022
and last updated 2022-08-12 22:48:28-04

SAN DIEGO (KGTV) – The painful rashes and lesions caused by monkeypox can last up to a month, and right now there are no proven treatments.

In a new paper, scientists say a drug invented at UC San Diego and approved for another disease shows promise as a therapeutic for monkeypox. But so far, the federal government has not backed a clinical trial.

“I don't understand,” said inventor Dr. Karl Hostetler. “It’s been effective in every animal model for pox virus, including for monkeypox, so why wouldn’t it be effective here?”

“Somebody needs to start thinking about organizing a trial,” he added.

Back in 1999, the UC San Diego professor got a call with a request from the National Institutes of Health. They wanted to see if he could adapt an injectable drug into a pill capable of fighting smallpox. The feds were worried terrorists could unleash smallpox as a bioweapon.

“They wanted something that could be given orally because it would be hard to give intravenous drug to hundreds of people or thousands of people,” Dr. Hostetler said.

The resulting drug, brincidofovir, was a success. Last year, it was approved by the FDA for use against smallpox under the brand name Tembexa. The drug is stashed in the Strategic National Stockpile.

For years, pre-clinical studies on animals and in petri dishes have shown the drug has activity against other viruses in the Pox family.

“Rabbitpox, mousepox, monkeypox; it was effective in all those models,” said Dr. Hostetler, who left the company that owns the rights to brincidofovir in 2012 but does retain some stock.

Two weeks ago, researchers at the University of Oklahoma reviewed potential drug candidates for monkeypox and flagged brincidofovir and another drug, tecovirimat, as “promising therapeutic options.” The article was published by Clinical Infectious Diseases.

“It tells me we should be doing clinical trials,” said Dr. Robert Schooley, the editor-in-chief of Clinical Infectious Diseases and a fellow professor at UC San Diego.

So far, there are clinical trials exploring tecovirimat as a treatment for monkeypox, but none on brincidofovir. On its website, the Centers for Disease Control and Prevention said it is currently developing an emergency authorization to facilitate the use of brincidofovir as a treatment for monkeypox.

Health officials have largely focused their efforts on vaccines for monkeypox, which remain in short supply.

“We've been slow on the uptake with monkeypox. Initially, people thought, ‘Well, it's a European problem. Well, I guess we have a few cases in the US. Good grief, we got a lot of cases in the US,’” Dr. Schooley said.

Both Schooley and Hostetler think researchers should run clinical trials on brincidofovir and tecovirimat head-to-head, to see which drug is superior in different patient populations.

“I think it's important to do them now rather than waiting until we have so many cases that it's very difficult to do the studies,” Dr. Schooley said.

The federal government has not released brincidofovir from the Strategic National Stockpile, and tecovirimat is difficult for doctors to obtain, Hostetler said.

“Both of them reduce viral load and should reduce transmission. If they were being used,” said Hostetler.

Relying on one investigational drug could be risky. Past research suggests small mutations in the virus could make tecovirimat ineffective, Schooley said, and monkeypox is mutating faster than expected.