Post-COVID Chronic Fatigue Following First SARS Outbreak (2003)

Post-COVID Chronic Fatigue Following First SARS Outbreak (2003) • Worldwide 8,098 people from 29 countries were infected and 774 died (9.6%) • In Hong Kong four years after the end of the outbreak, 233 SARS survivors were recruited to participate in a follow-up study of long-term morbidities of SARS

• Mean age was 43 and 70% were female • 27% of these SARS survivors met the CDC 1994 criteria for Chronic Fatigue Syndrome (CFS) Marco Ho-Bun Lam, et al. Arch Intern Med. 2009;169(22)2142-7.

Subset of AMP-516 CFS Patients with Shorter Disease Duration has Twice the Exercise Treadmill Tolerance (ETT) Response Compared to the ITT Population (n=208) • Mean duration of CFS symptoms for the ITT population was 9.6 years • Target subset had onset of symptoms of CFS between 2 and 8 years • The placebo adjusted percent of Ampligen patients in the Target subset with at least a 25% increase from Baseline was over twice that seen for the ITT population

AMP-516: Percent of Patients with at Least a 25% Increase* in ETT from Baseline; Greater Improvement with Ampligen Compared to Placebo 60 Percent of Patients

51.2%

50 40

39.0%

p=0.0131 (∆=15.9%)

p=0.0031 (∆=33.6%) 30.5%

30 20 10

p=0.541 (∆=4.8%)

Ampligen

25.7%

23.1% Ampligen

Placebo

17.6% Placebo

Ampligen Placebo

0 ITT Population

Target Subset

Non-Target Subset

1 p-values

derived from Chi-squared test * 25% increase based on a request from FDA (Division of Antiviral Drug Products ) to establish a meaningful percent change that is above intra-patient ETT Variability Strayer, et al. PLOS One 2020

3