Cidara Therapeutics (CDTX) 24th Annual Needham Virtual Healthcare Conference summary

Company and technology overview

• Cloudbreak immunotherapy platform evolved since 2014, leading to the DFC (drug-Fc conjugate) format in 2018 and the creation of CD388, a novel antiviral using zanamivir conjugated to an antibody Fc fragment.

• CD388 was reacquired in April 2024 after a divestiture by a previous partner, with a $240 million financing enabling the process.

• A 5,000-subject study was rapidly launched and fully enrolled by December 2023, coinciding with a severe flu season.

Clinical development and trial design

• CD388 is a long-acting antiviral targeting neuraminidase, designed to be more potent and longer-lasting than existing neuraminidase inhibitors.

• Phase II-A human challenge study showed a 57% placebo-adjusted response rate, outperforming Tamiflu in similar studies.

• Phase II-B study includes 5,000 subjects across four arms, with expectations of higher placebo event rates due to a severe flu season, potentially allowing for statistically significant results.

• Dose selection for phase III will be based on phase II-B outcomes, with all three tested doses expected to maintain efficacy throughout the flu season.

• Phase II-B is conducted in unvaccinated healthy adults; phase III will include high-risk and immunocompromised populations, with vaccination allowed.

Regulatory and market positioning

• Ongoing discussions with the FDA to revise the statistical analysis plan, with updates expected at a May 22nd R&D day.

• Phase III is planned to start in spring 2026 in the Southern Hemisphere, pending results, regulatory meetings, and capital availability.

• Initial market focus is on high-risk comorbid and immunocompromised populations, with potential expansion to elderly and other groups.

• CD388 is positioned as a single-dose seasonal prophylactic, with robust pricing potential compared to vaccines.