San Diego-based biotechnology startup Actio Biosciences announced Wednesday it has closed a $66 million Series B financing round to advance its pipeline of small molecule drugs targeting rare genetic diseases with potential applications in more common disorders. The financing was co-led by new investor Regeneron Ventures and existing backer Deerfield Management, with participation from Canaan, Droia Ventures, and Euclidean Capital.
The funding will support advancement of Actio's two lead programs: ABS-1230 for KCNT1-related epilepsy and ABS-0871 for Charcot-Marie-Tooth disease type 2C. Both programs represent the company's strategy of developing treatments that target the underlying biology shared between rare and common diseases.
KCNT1 Epilepsy Program Shows Broad Applicability
Actio's ABS-1230 represents a potential first-in-class oral, selective small molecule KCNT1 inhibitor designed to treat KCNT1-related epilepsy, a rare and often fatal pediatric epileptic encephalopathy affecting approximately 2,500 individuals in the United States. The condition strikes early and comes with severe health complications, including impacts on brain function and potential death.
"This kind of inclusive precision medicine is a key priority for the company," said David Goldstein, Actio's CEO and former co-founder of Praxis Precision Medicines. The company believes its approach holds advantages over competing programs from Praxis Precision Medicines, Servier, and Atalanta Therapeutics, which are pursuing different drugmaking methods.
In preclinical studies, ABS-1230 has demonstrated the ability to inhibit all recurrently observed pathogenic mutations in the KCNT1 gene, which causes overactivation of ion channels expressed in the brain. This broad activity makes ABS-1230 potentially applicable to many patients with KCNT1-positive epilepsy, according to the company.
Actio plans to initiate the healthy volunteer portion of a Phase 1 clinical trial of ABS-1230 in the second half of 2025, with expansion into a proof-of-concept Phase 1b study in KCNT1-related epilepsy patients planned for early 2026. The program has received both rare pediatric and orphan drug designations from the FDA.
Charcot-Marie-Tooth Program Advances to Patient Testing
The company's other lead program, ABS-0871, targets a different ion channel protein called TRPV4 and is currently enrolling patients in a Phase 1 trial with healthy volunteers. ABS-0871 is being developed for Charcot-Marie-Tooth disease type 2C, a degenerative nerve disorder characterized by severe muscle weakness and respiratory complications.
By the end of the year, Actio intends to start a Phase 1b study in people with the Type 2C form of Charcot-Marie-Tooth disease. The company also sees potential for ABS-0871 in treating overactive bladder, representing its strategy to leverage insights from rare disease research for more common disorders.
Funding Success Despite Market Challenges
Actio began raising its Series B round at the beginning of the year and successfully completed it despite an accelerating, sector-wide pullback that has made it harder for biotechnology companies to close funding rounds. Goldstein attributed the success to selecting programs with "very high biological plausibility."
"I'm sure that the climate will return back to funding those ideas that might be huge payoffs later, but it's just a little bit hard to predict," Goldstein said. "You really need to have programs that have a pretty predictable path."
The company emerged from stealth in late 2023 with $55 million in Series A funding and has since brought both small molecule drugs either into or near clinical testing. The latest financing brings Actio's total funding to $121 million as it advances its precision medicine approach targeting ion channel disorders.
"We have made tremendous progress across our pipeline – executing a precision medicine strategy that targets the root causes of disease through genetically informed drug development," Goldstein said. "ABS-1230 and ABS-0871 have the potential to be transformative disease-modifying therapies in their respective rare indications and growing evidence supports expansion into broader indications."
