Studies indicate that monkeypox has “several genetic pathways” to develop resistance and a single mutation would be equivalent to displacing the treatments that until now are available for patients at risk

The monkeypox virus is just one mutation away from evading a key antiviral drug used to treat at-risk patients, federal health officials now warn, urging doctors to be “cautious” when prescribing the treatment. wanted.

New FDA guidance for the antiviral drug known as tecovirimat, or Tpoxx, was published this week online and in updated labeling.

The regulator says that laboratory and animal studies, and evidence from a human case of this family of viruses, suggest that monkeypox has “several genetic pathways” for developing resistance to tecovirimat. Many “require only a single amino acid change,” the FDA said.

“Most patients with intact immune systems really do need supportive care and pain control, but they often don’t need to have their antiviral treatment intensified,” said Dr. Sapna Bamrah Morris of the Centers for Disease Control and Prevention. of diseases over the weekend, at a webinar hosted by the Infectious Diseases Society of America.

The Centers for Disease Control and Prevention (CDC) has been closely monitoring mutations in the virus to look for possible variants that could be resistant to monkeypox treatment. A portion of the positive tests across the country are sent to the genetic sequencing agency.

A recent cluster of cases prompted CDC labs to warn earlier this month of a “rare” mutation detected in California that caused “false negative” results on some tests.

So far no cases of a strain that can evade tecovirimat have been detected, although authorities warn that this “low barrier to resistance” poses the risk of a resistant variant emerging and spreading.

The FDA warning comes as federal health officials have been urging doctors to direct monkeypox patients to clinical trials recently launched by the National Institutes of Health to study the drug, rather than prescribing it themselves. , when it is possible.

Many monkeypox patients have reported excruciating rashes and lesions from their infections, and recovery can take weeks. The CDC now counts 22,630 cases nationwide. A handful of people have been hospitalized for complications from the virus.

The CDC on Tuesday reported two cases of previously healthy young men who were hospitalized after the virus spread to their brain and spinal cord.

Categorized in: