Hemispherx Biopharma Finishes Phase 3 CFS Clinical Trial; Completion of Placebo-Controlled Phase 3 Stage Represents Important Clinical Milestone.

Business Editors/Health/Medical Writers

PHILADELPHIA--(BUSINESS WIRE)--Jan. 30, 2004

Hemispherx Biopharma, Inc. (AMEX: HEB) announced today that it completes this week the randomization and placebo-controlled dosage stage of its Phase 3 clinical trial for Chronic Fatigue Syndrome (CFS), becoming the first pharmaceutical company to complete a pivotal trial in this disease category, which affects more than 500,000 Americans. The Company expects to present clinical data from this study in the second quarter of this year.

The clinical trial is a multi-center, double-blind, randomized, placebo-controlled Phase 3 pivotal study of the efficacy and safety of the experimental agent Ampligen(R) versus placebo in patients with severely debilitating Chronic Fatigue Syndrome (CFS).

The Company believes that efficacy will be established by showing medically and statistically significant improvement of the primary endpoint which is improved physical performance as measured by Treadmill Exercise Tolerance Testing (ETT): Duration. Efficacy may be established by showing a medically significant increase (greater than or equal to 6.5%) in mean exercise duration (baseline compared to week 40) that is statistically significant (p less than or equal to 0,05) using analysis of covariance of log10 transformed data with Baseline ETT duration as covariate. The Company will also analyze the median absolute changes in ETT duration between termination and baseline using the Mann Whitney test. The secondary endpoints of the study are various other indices of physical performance and cognitive activity.

About Chronic Fatigue Syndrome

CFS is defined by various governmental agencies as a serious debilitating disease in which patients suffer complex symptoms, including profoundly disabling fatigue, flu-like symptoms, headaches, sore throat, joint and muscle pain, mental fogginess, depression and sleep disorders. The U.S. Center for Disease Control and Prevention has added CFS to its top priority list of emerging infectious diseases. CFS is estimated to affect over 500,000 people in the U.S., and an equal number in Europe. At present, there is no other specific treatment available for CFS and no alternative drug appear to be under development in recognized clinical trials.