Glycomine, a U.S. biotech company focused on therapies for orphan diseases, announced a $115 million Series C financing round. The money will support advancement of its lead candidate, GLM101, into a Phase 2b randomized, placebo-controlled trial for treating PMM2-CDG (phosphomannomutase-2 congenital disorder of glycosylation).

PMM2-CDG is one of the more common congenital disorders of glycosylation. It arises from mutations in the PMM2 gene which impair glycosylation, a vital process in which sugar chains are attached to proteins. That defect can lead to multiple organ dysfunction, developmental delays, seizures, ataxia, and other serious symptoms. Currently there are no disease-modifying treatments approved; patients rely on supportive care.

GLM101 is not an enzyme replacement therapy in the usual sense. Instead of replacing the deficient PMM2 enzyme, it supplies mannose-1-phosphate, a downstream component needed in the glycosylation pathway. This strategy aims to bypass the block caused by reduced enzyme activity. The company reports that in its ongoing open-label Phase 2 trial (enrolling patients in Europe and the United States) the therapy has shown encouraging early signals: among nine adult or adolescent participants measured over 24 weeks there was an average 11.9-point improvement in ataxia on the international cooperative ataxia rating scale.

The newly raised capital will be used to initiate a placebo-controlled Phase 2b trial later in 2025. That will allow more rigorous assessment of safety and efficacy in a larger cohort and provide stronger data required for regulatory and clinical decisions.

Investors in this round include both newcomers and previous backers. Leading the round are CTI Life Sciences Fund, funds managed by abrdn, and Advent Life Sciences. Existing investors such as Novo Holdings, Sanofi Ventures, Abingworth, RiverVest Venture Partners, Sanderling Ventures, Chiesi Ventures, Remiges Ventures, and Asahi Kasei Ventures also participated. Steve Axon, Glycomine’s CEO, noted that with this support the company hopes to bring the first disease-modifying therapy for PMM2-CDG to patients who currently have no alternatives.

This development marks a significant milestone in rare disease clinical research. Disease-modifying treatments for CDGs (congenital disorders of glycosylation) have long been a goal but with many scientific and logistical barriers. The GLM101 program shows how targeted metabolic repair (in this case supplying what is lacking in the glycosylation pathway) may be viable. If Phase 2b data continues to support safety and meaningful clinical benefit, this could change the standard approach for PMM2-CDG and similar disorders.