Tuesday, Hemispherx Biopharma, Inc. (HEB), said it has received a Complete Response Letter from the U.S. Food and Drug Administration that indicated the two primary clinical studies on Ampligen, the company's chronic fatigue syndrome drug, did not provide credible evidence of efficacy. The company's shares tumbled 39% to 73 cents in late trading.
The company said that the FDA reviewers determined that they cannot approve the application in its present form and provided specific recommendations to address the outstanding issues. Hemispherx said that it was carefully reviewing the letter and will seek an expedited meeting with the FDA to discuss its recommendations. The company said it would make a thorough but prompt response its top priority, and plans to take all appropriate steps to seek approval and commercialization of Ampligen.
The FDA on its part stated that the two primary clinical studies submitted with the NDA did not provide credible evidence of the drug's efficacy and recommended at least one additional clinical study which shows a convincing effect and confirms safety in the target population. The additional study should be of sufficient size and sufficient duration of at least 6 months and include appropriate monitoring to rule out the generation of autoimmune disease.
In addition, patients in the study should be on more than one dose regimen, including at least 300 patients on dose regimens intended for marketing. Finally, the additional study must incorporate both a well-controlled QT interval study and pharmacokinetic evaluations.
Hemispherx said that other items required by the FDA include certain aspects of Non-Clinical safety assessment, and Product Quality. In the non-clinical area, the FDA recommended complete rodent carcinogenicity studies in two species.
As part of the NDA submission, the company had requested that these studies be waived, but the waiver had not been granted. Certain additional non-clinical studies and additional data to support non-clinical studies already submitted with the NDA are also recommended by the FDA. The company said that prior to the receipt of the Complete Response letter, it had already begun many of these additional studies and the collection of the requested additional data.
According to Hemispherx, the FDA recommends that it submit additional data and complete various analytical procedures, under the Product Quality section of the letter.
Hemispherx said that the collection of these data and the completion of these procedures is already part of its ongoing Quality Control, Quality Assurance program for Ampligen manufacturing under cGMP or current Good Manufacturing Practice Guidelines and the manufacturing enhancement program it recently undertook and announced in a news release on September 16.
Finally, the FDA noted the need to resolve outstanding inspection issues at the facilities producing the drug. These include the company facility located in New Brunswick, NJ and Hollister-Stier Laboratories, which is one of the company's third party manufacturing facilities. The company said that it has been working to resolve these issues.
Hemispherx said that at this time it has not determined the impact of the additional recommendations set forth in the Complete Response letter on the timelines and overall cost of the Ampligen program, but that its management has made response to the issues and satisfaction of any additional requirements a top priority.
HEB closed Tuesday's trade on the New York Stock Exchange at $1.20.
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