#USA #Boston #Huntington's Disease #Skyhawk Therapeutics #SKY-0515

Skyhawk Therapeutics Reports Positive Interim Results from Phase 1 Trial of SKY-0515

BOSTON, January 28, 2026 – Skyhawk Therapeutics, a clinical-stage biotechnology company, has announced promising interim data from its Phase 1 clinical trial of SKY-0515, a new treatment for Huntington's disease (HD). The preliminary findings after nine months of treatment indicate an average improvement of +0.64 points on the Composite Unified Huntington’s Disease Rating Scale (cUHDRS), contrasting sharply with the expected decline of -0.73 points in symptomatic patients during the same timeframe. This marks a significant breakthrough in the quest for effective therapies, as current projections for HD patients have anticipated worsening symptoms over nine months without treatment.

Dr. Ed Wild, a professor of neurology at University College London, expressed enthusiasm about these findings. He noted, "These data on safety and early efficacy from the Phase 1 trial demonstrate a deviation in cUHDRS scores from expected declines in the natural progression of the disease. The ability of SKY-0515 to significantly reduce mHTT protein levels stands out among treatments tested to date, highlighting its potential to address two fundamental pathogenic mechanisms of HD."

Clinical Study Overview

The Phase 1 clinical trial, which included healthy volunteers and individuals with early-stage Huntington’s disease, aimed to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of SKY-0515. The study was divided into three parts:

• - Part A and Part B examined safety and dosage levels in healthy volunteers.
• - Part C involved a double-blind, placebo-controlled evaluation in HD patients to quantify the effects of SKY-0515 on mHTT and mRNA protein PMS1, a protein linked to the progression of HD. Participants in this part experienced notable improvements at three, six, and nine months, further underscoring the medication's potential.

SKY-0515 led to a dose-dependent reduction of mHTT levels in the bloodstream by 62% at the 9 mg dosage, alongside a 26% reduction in PMS1 levels. Dr. Wild noted that these reductions suggest a synergistic effect in tackling the pathological underpinnings of Huntington's disease, offering hope for transformative results for patients.

Expansion of Clinical Trials

Skyhawk also announced that the ongoing Phase 2/3 trial, FALCON-HD, has expanded globally, having already administered SKY-0515 to over 90 patients across 12 sites in Australia and New Zealand. This trial will further investigate the drug’s efficacy and safety among a larger pool of participants. Sergej Pauškin, head of research and development at Skyhawk, stated, “The continuous strong biomarker response observed in our nine-month interim analysis and the improvement in cUHDRS relative to expected declines represent a critical milestone. It illustrates SKY-0515’s potential as a leading disease-modifying therapy for Huntington’s disease.”

Implications for Huntington's Disease Patients

Huntington's disease is a devastating, hereditary neurodegenerative condition affecting around 40,000 symptomatic individuals in the U.S., with hundreds of thousands more globally. Currently, there are no approved treatments capable of halting or slowing disease progression. Through its RKYSTAR® RNA-modulating platform, Skyhawk aims to develop innovative therapies that could change the landscape of treatment for this debilitating disorder.

As SKY-0515 is an experimental low-molecular-weight RNA modulator, it uniquely addresses the underlying mutations responsible for HD. Skyhawk plans to introduce more small molecule drugs targeting rare neurological conditions with no existing disease-modifying therapies by the end of 2027.

For ongoing updates on the clinic’s trials and the latest findings, interested parties can refer to ClinicalTrials.gov for information about the FALCON-HD study and its eligibility criteria.

About Skyhawk Therapeutics:
Skyhawk Therapeutics is a biotechnology company dedicated to developing small molecule therapies designed to modulate RNA for the treatment of severe diseases currently lacking effective therapies. For further details, visit their official website at skyhawktx.com.