Cocrystal Pharma, Inc. announces highly favorable safety and tolerability results for its orally administered replication inhibitor CC-42344 in its Phase 1 study. CC-42344 is a broad-spectrum antiviral for the treatment of pandemic and seasonal influenza A with a novel mechanism of action. The randomized, double-controlled Phase 1 study was conducted in Australia to evaluate the safety, tolerability and pharmacokinetics (PK) of CC-42344 given orally at single doses up to 800 mg and daily doses up to 14 days in 56 healthy volunteers.

Approximately 50% of the participants who received a single dose of CC-42344 across all dose levels (100 to 800 mg) experienced adverse events, similar to the proportion of placebo subjects who also experienced adverse events. In the multiple-dose section of the study, the incidence of adverse events was 67% for both CC-42344 (50 to 200 mg) and placebo. The vast majority of adverse events were mild in severity.

The most frequently reported adverse event was headache, which occurred at similar rates in CC-42344-treated and placebo-treated participants. There were no serious adverse events or drug discontinuation due to adverse events. Cocrystal plans to apply to the United Kingdom Medicines and Healthcare Products Regulatory Agency to conduct a Phase 2a human challenge study in early 2023.

Subject to regulatory clearance, the study is expected to be initiated in the second half of 2023. CC-42344 is an oral PB2 inhibitor discovered using Cocrystal's proprietary structure-based drug discovery platform technology. It is specifically designed to be effective against all significant pandemic and seasonal influenza A strains and to have a high barrier to resistance due to the way the virus' replication machinery is targeted.

CC-42344 targets the influenza polymerase, an essential replication enzyme with several highly conserved regions common to multiple influenza strains. In vitro testing showed CC-42344's excellent antiviral activity against influenza A strains, including pandemic and seasonal strains, as well as against strains resistant to Tamiflu® and Xofluza®, while also demonstrating favorable PK and safety profiles.