Cocrystal Pharma to Extend Phase 2a Influenza Challenge Study with Oral PB2 inhibitor CC-42344

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Cocrystal Pharma, Inc.
Cocrystal Pharma, Inc.
  • Data support favorable safety and tolerability profile with no serious adverse events (SAEs) or study-related drug discontinuations

  • Enrollment to be extended due to low influenza infection among challenged participants; virology results are uninterpretable

BOTHELL, Wash., Dec. 31, 2024 (GLOBE NEWSWIRE) -- Cocrystal Pharma, Inc. (Nasdaq: COCP) (“Cocrystal” or the “Company”) announces plans to extend enrollment in the Phase 2a human challenge study with its investigational, broad-spectrum, oral influenza PB2 inhibitor CDI-42344 due to unexpectedly low influenza infection among study participants who were challenged with a H3N2 viral strain. This randomized, double-blind, placebo-controlled Phase 2a study is evaluating the safety, tolerability, pharmacokinetics (PK), antiviral activity and clinical measurements of CC-42344 at a single site in the United Kingdom.

CC-42344 is a drug candidate in development as an oral treatment for pandemic avian and seasonal influenza A infections. In December 2023, Cocrystal Pharma announced enrollment of the first patient in this study and in May 2024, the Company announced full enrollment of 78 subjects.

“While CC-42344 showed a favorable safety and tolerability profile, we’re disappointed by the low infectivity rate of the challenge influenza strain used in this study. The establishment of robust influenza infection in healthy, uninfected study subjects is critical to determine clinical endpoints for evaluating antiviral molecules. The low infectivity obtained in this study hindered antiviral data analysis,” said Sam Lee, Ph.D., Cocrystal’s President and co-CEO.

“We remain optimistic about CC-42344 due to its unique mechanism of action with a high barrier to developing resistance, which could render it a best-in-class antiviral treatment for pandemic and seasonal influenza infections. We are also encouraged by CC-42344’s favorable safety and tolerability profile from the Phase 2a study to date, with no SAEs and no drug-related discontinuations by study participants.

“We are working with the clinical research organization to prepare a protocol amendment for approval by the United Kingdom Medicines and Healthcare Products Regulatory Agency (MHRA) in order to extend enrollment in this study, and to ensure necessary infection rates among enrolled study subjects,” he added.

About CC-42344

CC-42344 is a new class of antiviral treatment designed to effectively block an essential step in the viral replication and transcription of pandemic and seasonal influenza A and was discovered using the Company’s proprietary structure-based drug discovery platform technology. CC-42344 showed excellent in vitro antiviral activity against pandemic and seasonal influenza A strains, as well as strains that are resistant to Tamiflu® and Xofluza®. In late 2022, Cocrystal reported favorable safety and tolerability results from a Phase 1 study in healthy subjects conducted in Australia. The Company initiated the Phase 2a human challenge study in December 2024 following authorization from the MHRA. In June 2024, the Company reported in vitro studies demonstrating that CC-42344 inhibited the activity of the PB2 protein in the new highly pathogenic avian influenza A (H5N1) PB2 protein recently identified in humans.