Saol Therapeutics, a US-based clinical-stage pharmaceutical company, announced on Monday that the US 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 paediatric mitochondrial disease, Pyruvate Dehydrogenase Complex Deficiency (PDCD).

SL1009 has been granted Orphan Drug, Priority Review, and Rare Pediatric Disease Designations by the FDA.

In the letter, 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. According to Saol, it would take several years and require significant financial resources to address the deficiencies as the FDA requested.

Saol said that it 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 added that it believes strongly that SL1009, with its established safety profile, could be an important treatment option for patients with PDCD.

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

Citing the urgent unmet medical need faced by the PDCD community, Saol said that it remains dedicated to working with the FDA towards a resolution. Further updates will be provided as this dialogue progresses.

SL1009 has received Priority Review, Orphan Drug Designation, and Rare Pediatric Disease Designation. Saol, in collaboration with Medosome Biotec, has 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.