San Diego, California, USA, April 7, 2026
Broad U.S. Availability Expands Patient Access
In a major advancement for rare neurological disorder treatment, Acadia Pharmaceuticals Inc. has announced that DAYBUE® STIX (trofinetide) is now broadly available across the United States for the treatment of Rett syndrome in both adult and pediatric patients aged two years and older. The newly introduced powder formulation for oral solution represents a significant step forward in patient-centric drug delivery, offering greater flexibility, portability, and ease of administration compared to the original liquid formulation.
Approved by the U.S. FDA in December 2025, DAYBUE STIX is bioequivalent to the original formulation, delivering the same efficacy and safety profile while allowing caregivers to customize dosing and taste preferences by mixing the powder with various liquids. This expanded availability marks a critical milestone in improving real-world treatment accessibility and adherence for patients living with this complex neurodevelopmental disorder.
Patient-Centric Innovation Enhances Treatment Experience
DAYBUE STIX has been developed with a strong focus on caregiver convenience and patient needs, addressing challenges associated with administering medication in individuals with Rett syndrome, who often require long-term, highly individualized care. The formulation comes in pre-measured, portable packets, enabling on-the-go administration and reducing the burden on caregivers managing daily treatment routines. Early feedback from caregivers indicates that over 80% of users reported satisfaction, particularly highlighting improvements in flexibility and ease of use.
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Additionally, the ability to mix the formulation with common beverages such as juice or hydration liquids allows for better patient compliance, especially in pediatric populations. These features align with growing industry emphasis on patient-centric drug design, where ease of administration and quality of life improvements are becoming critical components of therapeutic innovation.
Clinical Validation Supports Standard of Care Integration
The clinical foundation of DAYBUE STIX is supported by the pivotal Phase 3 LAVENDER™ study, which demonstrated clinically meaningful improvements in Rett syndrome symptoms, along with a well-characterized safety profile. The approval of the STIX formulation was based on bioequivalence studies, confirming that both formulations provide comparable systemic exposure and therapeutic outcomes. Importantly, recent expert consensus recommendations have recognized trofinetide as part of the standard of care for Rett syndrome, emphasizing the importance of early initiation, sustained treatment, and individualized care strategies.
These guidelines further reinforce the role of DAYBUE as a foundational therapy in managing Rett syndrome, particularly in addressing core neurological deficits linked to synaptic dysfunction. As Rett syndrome is caused by mutations in the MECP2 gene, therapies like trofinetide aim to improve synaptic communication and neuronal function, offering a mechanism-driven approach to treatment.
Advancing Rare Disease Treatment Landscape
Rett syndrome is a rare and debilitating neurodevelopmental disorder, affecting approximately 1 in 10,000 to 15,000 female births worldwide, and is characterized by developmental regression, loss of motor and communication skills, and lifelong neurological impairment. Patients often require round-the-clock care, placing a significant burden on families and healthcare systems. The broad availability of DAYBUE STIX represents a meaningful step toward improving treatment accessibility and quality of care, particularly in a disease area with historically limited therapeutic options.
Acadia’s continued focus on innovation in rare CNS disorders underscores its commitment to delivering transformative therapies that address both clinical outcomes and real-world patient needs. As the company advances its broader pipeline across neurodegenerative and neuropsychiatric conditions, DAYBUE STIX exemplifies the growing importance of patient-centered pharmaceutical innovation in shaping the future of rare disease management and care delivery.
Source: Acadia Pharmaceuticals press release
