Efficacy of Cont®aFlu, a novel antibody TLR3 modulator in the self-treatment of common cold: the ESTUAR trial
Context: Since the discovery of toll-like receptor 3 (TLR3), no specific tools have been developed to modulate its activity in upper respiratory tract viral infections (URTIs). Cont®aFlu (oral antibodies to TLR3 cytoplasmic fragment) is the first specific TLR3 modulator that showed efficacy in a mouse model of influenza.
Objective: To evaluate the efficacy of Cont®aFlu in URTI.
Methods: A double blind randomized placebo-controlled trial in adults with self-reported URTI (the ESTUAR trial) was conducted in 2012/2013 in Belgium. Adult outpatients started a 7-day treatment course with oral tablets of Cont®aFlu or placebo within 36 h after onset of at least one of 4 typical symptoms of URTI. Patients were examined twice by their general practitioners, on days 2-3 and 10-14 after start of treatment. The primary endpoint was the overall severity of URTI calculated as the sum of Wisconsin Upper Respiratory Symptom Survey (WURSS-21) scores over the follow-up. Independent Student’s t test was used to compare the disease severity between groups.
Results: A total of 243 patients were enrolled by 32 investigators (121 Cont®aFlu, 122 placebo); 92% of cases matched ICD codes J00 or J06. Most patients had very mild (41.8%) or mild (18.2%) URTI symptoms. In the ITT cohort, neither primary nor secondary outcome measures (duration of URTI, day-to-day and overall functional impairments) showed statistically significant differences between groups. The rate of adverse events was similar in both groups.
In patients with moderate to severe URTI symptoms, Cont®aFlu tended to reduce the overall disease severity, daily symptoms, and to improve the functional state. Due to the small size of the corresponding subgroups, Cont®aFlu efficacy on daily scores was statistically significant (p < 0.05) only 1, 2, and 5 days after start of treatment.
Conclusion: Cont®aFlu was ineffective in mild URTI and showed efficacy in moderate to severe URTI cases.