Saol Therapeutics Receives Complete Response Letter from FDA for SL1009 (DCA) for the Treatment of Pyruvate Dehydrogenase Complex Deficiency (PDCD)

Saol is seeking a path forward with the FDA that does not require an additional trial

ROSWELL, Ga. and DUBLIN and HAMILTON, Bermuda, Sept. 8, 2025 /PRNewswire/ -- Saol Therapeutics, a privately held, clinical-stage pharmaceutical company, today announced that the U.S. Food and Drug Administration (FDA) has issued a Complete Response Letter (CRL) regarding its New Drug Application (NDA) for SL1009, Sodium Dichloroacetate Oral Solution (DCA) for use with a proprietary genetic test, for the treatment of an orphan pediatric mitochondrial disease, Pyruvate Dehydrogenase Complex Deficiency (PDCD). SL1009 has been granted Orphan Drug, Priority Review, and Rare Pediatric Disease Designations by the FDA.

PDCD affects fewer than 1,000 individuals in the U.S., with an incidence estimated at 1 in 40,000 live births, approximately 90 newborns annually¹. Most children diagnosed with PDCD, especially those with early-onset forms, face overwhelming health challenges, and many do not survive beyond early childhood. There are currently no FDA-approved treatments for PDCD.

The FDA provided specific observations within the CRL that Saol will need to address to clarify the path forward.  These observations did not include any findings regarding the manufacturing of SL1009. To address the deficiencies as the FDA requested, it would take several years and require significant financial resources.

Saol remains encouraged by the four years of clinical data captured through two phase III studies, a double-blind placebo-controlled trial that continues in open-label extension, and a survival analysis compared to a natural history cohort. Saol feels strongly that SL1009, with its established safety profile, could be an important treatment option for patients with PDCD.

"Families living with PDCD face an urgent and life-threatening unmet need," said Dave Penake, CEO of Saol Therapeutics. "We are encouraged by recent FDA actions and commentary that recognize the importance of regulatory flexibility and speed for treating rare diseases. Traditional clinical trials often take many years; time that children with PDCD simply do not have. We remain committed to productive conversations with the Agency to identify a path forward that brings this therapy to patients as swiftly as possible."

In the interim, Saol reaffirms that access to SL1009 will continue without interruption through both the ongoing open-label extension of the clinical trial (NCT02616484) and the Expanded Access Program (NCT06931262) which also includes emergency support for neonates with life-threatening lactic acidosis due to inborn errors of metabolism.

Saol appreciates the urgent unmet medical need faced by the PDCD community and remains dedicated to working with the FDA towards a resolution. Further updates will be provided as this important dialogue progresses.

About SL1009, Sodium Dichloroacetate (DCA)
SL1009 is an investigational product that, if approved, will be used with a proprietary dose-determining genetic test to treat an orphan pediatric-onset mitochondrial disease, Pyruvate Dehydrogenase Complex Deficiency (PDCD). PDCD is a rare and life-threatening genetic disorder that can cause chronic energy deficit leading to lactic acidosis, profound developmental problems, and early childhood death. There are currently no FDA-approved therapies for PDCD.

SL1009 has received Priority Review, Orphan Drug Designation, and Rare Pediatric Disease Designation. Saol, in collaboration with Medosome Biotec, also filed the Humanitarian Device Exemption (HDE) application for the dose-determining genetic test that will serve as a required companion diagnostic for patients treated with SL1009.

About Saol Therapeutics
Saol Therapeutics (pronounced "Sail") is a privately held, clinical-stage, pharmaceutical company with operations in Roswell, GA, Dublin, Ireland, and Hamilton, Bermuda. Saol is focused on development activity in CNS disorders such as spasticity and pain management, and orphan diseases. Saol is committed to providing and advancing therapeutic options for patients and the physicians treating these populations. For more information, visit www.saolrx.com. 

¹ Bedoyan JK. Pyruvate Dehydrogenase Complex Deficiency. Medlink Neurology. 2024 May;  https://www.medlink.com/articles/pyruvate-dehydrogenase-complex-deficiency

Saol Therapeutics Contact
Anna Stallmann
[email protected]

SOURCE Saol Therapeutics