Nature newsblog

Panel rejects experimental chronic fatigue syndrome drug

21 Dec 2012

Posted by Heidi Ledford

A drug for chronic fatigue syndrome that spent decades in clinical development and won fervent
patient support has been turned down for approval by a committee of advisers to the US Food and
Drug Administration (FDA) who voted 9–4 against it. The drug, named Ampligen (rintatolimod), has
not been shown to be effective or safe, the committee determined on 20 December.

Ampligen is a double-stranded RNA molecule (called poly I:poly C) which is thought to stimulate the
immune system.

The FDA does not have to follow the recommendations of its advisers, but briefing
documents (http://1.usa.gov/WBj9cd) released by the agency strongly suggest that it will. The FDAfs
list of deficiencies in the drug application submitted by Hemispherx Biopharma (http://bit.ly/WBjtb9) is
stunning and encompasses nearly every aspect of clinical testing.

gKey deficiencies included inadequate evidence of effectiveness or safety, inadequacy of drug–drug
interaction studies, lack of carcinogenicity assessment, lack of anti-drug antibody
determination, and inadequate analytical methods and drug product specifications,h

the agency wrote in one of several sections listing problems associated with the application.

FDA representatives also expressed concern over inconsistencies in the data and statistical analyses.
An agency representative says of the data:

gIt raises our eyebrows and makes us wonder what else is in the database that wefre not seeing.h

Despite these weighty caveats and the drugfs middling performance in the clinic when averaged
across all patients, several people with chronic fatigue syndrome (CFS; also called myalgic
encephalomyelitis) testified that Ampligen yielded dramatic improvements in their symptoms. Some
moved to Reno, Nevada, to be near the clinical-testing site and to receive infusions of the drug.

Alaine Perry, who served as a patient representative on the advisory committee, acknowledged that the
Ampligen data are slim, but noted that CFS symptoms can be so severe that some patients
would willingly take on a significant mortality risk for the promise of even minor relief of their

gA very small improvement in a disease like this is life altering,h

she said. There are no other approved treatments specifically for CFS.

Accelerated approvals are sometimes used in cases of serious unmet medical need, and there was
speculation ahead of Thursdayfs meeting that recent legislation charging the FDA with expanding
its use of accelerated approvals may come to bear on Hemispherxfs application.

Ultimately, however, the FDA is bound by requirements that drug-makers convincingly
demonstrate efficacy before approval, representatives said.

In fact, according to the FDA briefing documents, the agency made it clear to Hemispherx in June
that its application would be unlikely to win approval without additional clinical trials.

That revelation probably came as a surprise to many Hemispherx investors, noted (http://bit.ly/WBlioh)
The Streetfs Adam Feuerstein.