Earlier today, Skyhawk provided the below update on Part C of their SKY-0515 Phase 1 trial.

----Community Letter------

Dear Skyhawk friends and colleagues,

We are delighted to today announce the first interim results from the Part C patient cohort of our SKY-0515 Phase 1 clinical trial for the treatment of Huntington's disease. Below and linked here is the press release.

As seen in the above image, by Day 84 patients receiving SKY-0515 demonstrate dose-dependent reductions of mHTT protein in blood, including 62% on the 9mg daily oral dose, with treatment ongoing.

Treatment with SKY-0515 also results in important dose-dependent PMS1 mRNA reduction and demonstrates excellent central nervous system penetration. The drug has been generally well tolerated at both dose levels tested, supporting continued clinical development, and our Phase 2/3 FALCON-HD trial in patients is now enrolling in Australia and New Zealand.

“SKY-0515 is reducing mHTT protein to the most impressive extent we've seen so far in patients, and crucially the clinical and biomarker data show no safety concerns so far at any dose tested,” said Ed Wild, Professor of Neurology at University College London. “It is great that we are seeing substantial PMS1 reduction as well, which should be a potent combination for treating Huntington's disease via two of its core pathogenic mechanisms. This is what success looks like at the 3-month timepoint, setting the stage for meaningful impact for people living with HD across the world – for whom an orally administered huntingtin-lowering treatment such as SKY-0515 would be truly transformative."

“The strength of SKY-0515's biomarker response after just 84 days of treatment underscores its potential as a transformative therapy for HD,” said Sergey Paushkin, Head of R&D at Skyhawk Therapeutics. “These interim data represent an important milestone for SKY-0515 and highlight the power of Skyhawk's platform to deliver first-in-class small molecules for devastating diseases with no approved disease-modifying therapies.”

Skyhawk plans to put a series of additional novel drugs for rare neurological conditions with no disease-modifying therapies in the clinic by the end of 2027. The first is on track to initiate trials in mid-2026.

We are excited about the progress toward helping patients, and are grateful for your support!

Read Press Release

With all our very best, Maura & the Skyhawk team~