BOSTON, Mass. — July 14, 2026
Skyhawk Therapeutics, Inc. has announced a major expansion of its global pivotal Phase 2/3 FALCON-HD clinical trial evaluating SKY-0515, an investigational oral RNA splicing modifier for Huntington’s disease (HD), following new regulatory approvals in the United States, Canada, and the United Kingdom. The company confirmed that the U.S. Food and Drug Administration (FDA) accepted its Investigational New Drug (IND) application, while regulatory authorities in Canada and the United Kingdom granted Clinical Trial Application (CTA) approvals, allowing patient enrollment to begin across these regions. The expansion significantly broadens the international footprint of the pivotal program, with more than 10 countries, over 20 clinical sites, and more than 175 patients enrolled across the SKY-0515 development program. The milestone strengthens Skyhawk’s efforts to accelerate development of a potential disease-modifying therapy for Huntington’s disease, a rare and fatal inherited neurodegenerative disorder for which no approved treatment has yet demonstrated the ability to slow or halt disease progression.
Global Pivotal Trial Expands Across Major International Markets
The FALCON-HD (004-ANZ and 004-WW) program is a randomized, double-blind, placebo-controlled Phase 2/3 clinical trial designed to evaluate the efficacy, safety, pharmacodynamics, and dose response of SKY-0515 in patients with Stage 2 and early Stage 3 Huntington’s disease. The Australia and New Zealand portion of the study has already completed enrollment with 144 participants, while the worldwide expansion is expected to recruit up to 400 additional patients across more than 40 clinical sites globally. With regulatory approvals now secured in the United States, Canada, and the United Kingdom, investigators are expanding enrollment into several of the world’s leading neurological research centers. The broader international study is expected to generate robust clinical evidence supporting future regulatory submissions while providing greater access for patients seeking participation in innovative Huntington’s disease research.
Twelve-Month Data Strengthens Confidence in SKY-0515
The trial expansion follows encouraging 12-month Phase 1/2 clinical results demonstrating that SKY-0515 has been generally well tolerated while delivering meaningful improvements across several key disease biomarkers. Clinical findings showed a 69% reduction in mutant huntingtin protein (mHTT) and a 26% reduction in PMS1, a DNA repair protein associated with disease progression. Researchers also reported improvements in the Composite Unified Huntington’s Disease Rating Scale (cUHDRS), contrasting with the functional decline typically observed in the natural progression of Huntington’s disease. SKY-0515 is an orally administered small-molecule RNA splicing modifier developed using Skyhawk’s proprietary SKYSTAR® platform, designed to selectively reduce disease-causing proteins while preserving normal cellular function. These promising biomarker and functional outcomes provide a strong scientific foundation for advancing the pivotal global program toward potential regulatory approval.
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Skyhawk Advances Precision RNA Therapeutics for Rare Neurological Diseases
The expansion of FALCON-HD reinforces Skyhawk Therapeutics’ leadership in developing RNA-targeted small-molecule therapies for neurological disorders with significant unmet medical needs. Huntington’s disease affects more than 40,000 symptomatic individuals in the United States, with hundreds of thousands more affected worldwide through inherited genetic risk. Current therapies primarily address symptoms and do not modify disease progression, highlighting the urgent need for innovative treatment approaches. Through its SKYSTAR® RNA splicing platform, Skyhawk is developing multiple precision therapies targeting rare neurological diseases while planning to advance several additional candidates into clinical development by 2027. As the global FALCON-HD study continues enrolling patients across North America, Europe, Australia, and New Zealand, SKY-0515 has the potential to become one of the first oral disease-modifying therapies capable of altering the biological course of Huntington’s disease while expanding treatment options for patients worldwide.
Source: Skyhawk Therapeutics press release
