Advocates and lawmakers are calling for the Biden administration to remove barriers to access for a promising medication called tecovirimat, or TPOXX, as New York’s monkeypox outbreak worsens.

So far, the U.S. Food and Drug Administration has only approved the medication for the treatment of smallpox — though some early studies show TPOXX can help against monkeypox, too. The drug is an antiviral, meaning it tries to keep the virus from thriving once the germ is already harming the body. That’s in contrast to the monkeypox vaccine, which tries to stop the disease before it starts.

If a health care provider wants to try TPOXX for a monkeypox patient, they have to obtain special approval through the Centers for Disease Control and Prevention and its “Investigational New Drug” program. The program is designed to gather data on the effectiveness of TPOXX for treating monkeypox — but comes with extra steps and paperwork. This particular drug is also being supplied via the country’s Strategic National Stockpile, given that it is kept in reserve to thwart a smallpox bioterrorism attack.

State Sen. Gustavo Rivera, chairman of the Senate Health Committee, and about a dozen other state legislators sent a letter on Monday to Xavier Becerra, the secretary of the U.S. Department of Health and Human Services, urging him to consider an emergency use authorization for TPOXX, similar to the ones issued for COVID-19 vaccines before they were fully approved.

The Medical Society of the State of New York, which represents doctors, released a statement the same day calling on Becerra and President Joe Biden to declare monkeypox a public health emergency so that the FDA could evaluate TPOXX for emergency authorization.

“Tecovirimat shows great promise in the treatment of monkeypox infection, and the Emergency Investigatory New Drug restrictions have limited the ability to treat patients with this medication,” Dr. Parag Mehta, president of the Medical Society, said in the statement.

The state legislators noted in their letter that, given the strain workforce shortages have placed on health care institutions, some are finding it difficult to comply with the additional requirements.

In recent days, both New York City Mayor Eric Adams and Gov. Kathy Hochul have issued emergency declarations around monkeypox that they say will expand their powers to address the outbreak and offer funding avenues for outbreak health care.

Callen-Lorde Community Health Center, which operates clinics in the Bronx and Manhattan serving the LGBTQ population, has dedicated a six-person team to guiding patients through the complicated protocols associated with TPOXX once a clinician recommends the drug, said Dr. Asa Radix, the organization’s director of research and education.

“Most small practices cannot do this,” Radix said, adding that some patients get swabbed by other providers and then referred to Callen-Lorde for TPOXX. “We're lucky because we just had a study end, so we had some time to jump on this right away.”

Radix said Callen-Lorde has prescribed TPOXX to about 90 patients so far — about one in five of the prescriptions issued citywide. As of Tuesday, New York City health care providers had prescribed TPOXX to more than 450 monkeypox patients, according to the city health department, which is offering assistance with meeting CDC requirements. There have been more than 1,500 cases of monkeypox reported in the five boroughs so far, according to city data.