FDA Supports Novel Endpoints for ABLi Therapeutics' Risvodetinib Phase 3 Trial in Parkinson's Disease
Key Insights
ABLi Therapeutics (search) has completed an End of Phase 2 meeting with the FDA, securing support for innovative endpoints in upcoming Phase 3 trials for risvodetinib in Parkinson's disease (search).
The FDA endorsed ABLi's proposal to use delay in levodopa/carbidopa initiation as a novel endpoint, potentially establishing a direct measure of disease modification rather than just symptom management.
Risvodetinib, a c-Abl kinase inhibitor, demonstrated both clinical improvement and reduction of pathological alpha-synuclein (search) in Phase 2 trials, positioning it as a potential first-in-class disease-modifying therapy for Parkinson's.
ABLi Therapeutics (search) announced successful completion of an End of Phase 2 (EOP2) meeting with the FDA regarding risvodetinib, its investigational treatment for Parkinson's disease (search). The agency has endorsed the company's proposed endpoints for upcoming Phase 3 trials, including a novel approach that could demonstrate disease-modifying effects rather than just symptom management.
FDA Endorses Innovative Trial Design
The primary focus of the EOP2 meeting was to establish appropriate endpoints for Phase 3 trials and outline requirements for a potential New Drug Application (NDA). ABLi presented data from its 201 Trial showing that risvodetinib reached nominal significance for the Movement Disorder Society revision of the Unified Parkinson's Disease (search) Rating Scale (MDS-UPDRS) and the Schwab & England Activities of Daily Life (SEADL) scale during a 12-week treatment period.
The FDA supported ABLi's proposal to use the change in MDS-UPDRS Part 2 as the primary outcome measure for Phase 3, aligning with the agency's preference for endpoints that evaluate patient quality of life as a meaningful assessment of clinical benefit.
Novel Disease-Modifying Endpoint Approved
In a significant development, the FDA agreed with ABLi's proposal to utilize a novel endpoint: measuring the time before patients require levodopa/carbidopa treatment initiation. The company believes this approach provides a direct measure of disease modification, as delaying the need for standard symptomatic therapy would indicate slowing of disease progression.
"This novel endpoint represents a potential paradigm shift in how we evaluate disease-modifying therapies for Parkinson's disease (search)," said Milton H. Werner, PhD, Chairman and CEO of ABLi Therapeutics (search). "The FDA's support validates our approach to targeting the underlying disease mechanisms rather than just managing symptoms."
The agency encouraged a follow-up meeting to establish specific clinical standards for determining when trial participants should begin levodopa/carbidopa treatment.
Simplified Safety Monitoring Requirements
The FDA also simplified vision monitoring requirements for the Phase 3 program, reducing the frequency to six-month intervals until one-year dosing data is reviewed. This decision follows observations that no risvodetinib-related vision impacts were detected in participants receiving daily doses for up to 12 weeks during Phase 2 trials.
Biomarker Development Continues
The agency encouraged ABLi to continue evaluating skin biopsy and other biological fluid measures as potential prognostic markers of treatment success. The company views quantitative measurement of alpha-synuclein (search) clearance as an important supportive measure alongside clinical assessments.
ABLi notes that risvodetinib is the first Parkinson's treatment that has demonstrated reduction of pathological alpha-synuclein (search) in conjunction with clinical benefit. This is particularly significant as neuronal alpha-synuclein deposition in various aggregated and fibrillar forms is now recognized as a hallmark of all forms of Parkinsonism.
Potential First Disease-Modifying Therapy
Risvodetinib (ABLi-148009) is a potent, selective small-molecule inhibitor of non-receptor c-Abl kinases (search), designed for once-daily oral administration. The drug targets underlying biological mechanisms driving Parkinson's disease (search) initiation and progression.
Unlike currently available treatments that only manage symptoms, risvodetinib aims to halt disease progression and potentially reverse functional loss arising from Parkinson's disease (search). The compound was recently the first monotherapy to improve patient quality of life in a randomized, placebo-controlled clinical trial while simultaneously reducing underlying disease pathology in untreated Parkinson's disease.
The drug currently has intellectual property protection beyond 2036, providing a substantial runway for development and commercialization if approved.
Addressing a Critical Unmet Need
Parkinson's disease (search) affects approximately 10 million people worldwide, with prevalence expected to double by 2040 as the global population ages. Current therapeutic approaches only address symptoms without affecting disease progression.
ABLi Therapeutics (search) focuses on developing small molecule therapeutics targeting diseases arising from activation or dysfunction of the Abelson Tyrosine Kinases (search) (c-Abl). Beyond Parkinson's disease (search), the company is exploring applications for related neurodegenerative conditions including Multiple System Atrophy (search) and Dementia with Lewy Body (search), which are also associated with Abl kinase activation or dysfunction.
The company's approach leverages medicinal chemistry and disease biology understanding to develop compounds with enhanced brain penetration, greater potency, target selectivity, and improved safety profiles compared to existing kinase inhibitors.
Next Steps
Following the successful EOP2 meeting, ABLi Therapeutics (search) will proceed with finalizing the Phase 3 trial design and preparing for trial initiation. The company has indicated it will provide updates on trial timelines and additional details on the Phase 3 program in upcoming communications.