U.S. regulators defend requiring more data on monkeypox drug

SIGA Technologies

03/08/2022 22:36

By Julie Steenhuysen
    CHICAGO, Aug 3 (Reuters) - As U.S. monkeypox cases rise,
U.S. health agencies in a medical journal article published on
Wednesday defended their decision to require human trial data to
show that SIGA Technologies'  SIGA.O  experimental drug TPOXX is
safe and effective to treat the virus. 
    U.S. agencies have been under pressure to ease access to the
drug, which is being distributed by the U.S. Centers for Disease
Control and Prevention (CDC) under a special "compassionate use"
access that requires doctors to request it from the agency or
their health department and enroll each patient in a study. 
    As of July 22, 223 people have been treated with the drug,
compared with more than 6,000 known cases in the United States.
    The FDA approved TPOXX in 2018 for smallpox in adults and
children based on studies of animals infected with monkeypox and
rabbitpox, as well as safety data in healthy people. It can only
be sold to the U.S. Strategic National Stockpile.
    Authors of the article in the New England Journal of
Medicine from the Food and Drug Administration, the CDC and the
National Institutes of Health (NIH) said the latter is planning
a U.S.-based randomized clinical trial.
    Data from that study will be used to determine whether the
drug gains U.S. approval for monkeypox.
    The drug, also known as tecovirimat, is approved for both
smallpox and monkeypox in the UK and Europe. The European Union
approved it under an "exceptional circumstances" pathway that
allows for marketing approval when data cannot be obtained even
after authorization.
    Although TPOXX was only tested in healthy people, the
European Medicines Agency said it expects side effects to be
similar in infected people, and deemed the drug's benefits to be
greater than its risks.
    Dr. Jay Varma, director of the Cornell Center for Pandemic
Prevention and Response who has advocated for broader access to
the drug, said the FDA's standards ensure U.S. drugs are safe
and set a high bar for the world, but in some circumstances,
"those strict standards are harming us."
    There were 1.7 million doses of the treatment in the U.S.
Strategic National Stockpile at the start of the current
outbreak in May.
    On July 21, the CDC and the FDA began allowing doctors to
prescribe the drug before the trial paperwork is completed, but
still requires approval of a hospital's institutional review
board for each dose.
    "It's definitely better. It's still very burdensome," said
Dr. Karen Krueger, an infectious disease expert at Northwestern
Medicine in Chicago, who said there is additional paperwork
after the patient visit and for several follow-up visits.
    "It's doable but certainly a lot more challenging than how
we normally prescribe drugs."
    Neither the FDA nor the CDC immediately responded to a
request for comment.
    Northwestern has treated at least 20 monkeypox patients with
TPOXX and will be one of the sites for the NIH trial.
    To win approval, SIGA Chief Scientific Officer Dennis Hruby
estimates it will likely take a 500-patient, placebo-controlled
clinical trial in the United States. 
    If cases remain high, the trial could be fully enrolled
within a few months. "It's not a terribly long trial," he said. 
    SIGA Chief Executive Phillip Gomez said the company is
working to launch trials in the UK, Canada, the United States
and Europe.
    If the United States declares monkeypox a national
emergency, Gomez said the drug could be granted an emergency use
authorization. However, because the FDA has been "very clear"
they want full, placebo-controlled trials, that could still take
time, he said. 

 (Reporting by Julie Steenhuysen in Chicago; additional
reporting by Natalie Grover in London; Editing by Bill Berkrot)
 ((julie.steenhuysen@thomsonreuters.com; 312-408-8131; Reuters
Messaging: Julie.steenhuysen.reuters.com@reuters.net))