Pipeline & Regulatory
Advancing arbaclofen toward approval.
Allos is advancing arbaclofen across genetically informed and clinically defined neurodevelopmental disorders, with initial focus on Autism Spectrum Disorder and Fragile X Syndrome.
Programs
Current pipeline.
The Allos pipeline is built upon decades of clinical experience with arbaclofen and multiple positive efficacy signals across neurodevelopmental disorders. Unlike many early-stage CNS programs, Allos is advancing assets supported by extensive human safety data, prior controlled clinical studies, orphan drug opportunities, and established regulatory engagement. Current development efforts are focused on Autism Spectrum Disorder (ASD), Fragile X Syndrome (FXS), and genetically defined neurodevelopmental disorders where social and communication impairments remain significant unmet medical needs.
| Program | Preclinical | Phase 2 | Phase 3 | NDA | Status |
|---|---|---|---|---|---|
| Arbaclofen — Fragile X Syndrome | Confirmatory Phase 3 planned | ||||
| Arbaclofen — Autism Spectrum Disorder | Pre-NDA meeting July 2026 | ||||
| Arbaclofen — 16p11.2 deletion | L16hthouse Phase 2 complete |
Detail
Pipeline Detail
Allos Pharma is advancing arbaclofen across genetically informed and clinically defined neurodevelopmental disorders, with an initial focus on Autism Spectrum Disorder and Fragile X Syndrome. Arbaclofen targets and corrects the underlying molecular pathophysiology through a dual mechanism of action, and treatment effects are multi-faceted and disease-modifying. Across more than 700 children, adolescents, and adults with FXS and ASD, arbaclofen has demonstrated excellent safety and tolerability. The company's development strategy builds on decades of translational neuroscience, clinical experience, and mechanistic understanding of inhibitory signaling pathways relevant to social and behavioral function.
Autism Spectrum Disorder (ASD)
A broad population neurodevelopmental disorder. Clinically meaningful improvements in socialization and communication observed in the Seaside Therapeutics ASD clinical trials have been replicated in placebo controlled confirmatory trials. Allos has a pre-NDA meeting with the FDA scheduled for July 2026.
Fragile X Syndrome (FXS)
A genetically defined neurodevelopmental disorder with Orphan Drug Designation in both the US and EU. A confirmatory Phase 3 trial is planned, with an FDA-aligned design in preparation.
16p11.2 Deletion Syndrome
A genetically defined neurodevelopmental disorder. The Lighthouse Phase 2 program is complete.
Arbaclofen is an investigational compound and is not approved for any use in any country.
Partnership
Let's bring arbaclofen to the patients and families who need it.
Partner with Allos to accelerate the first disease-modifying treatment for ASD and Fragile X Syndrome.