MedPath

Glycomine Secures $115M Series C Funding to Advance Novel Treatment for PMM2-CDG Rare Disease

3 months ago4 min read

Key Insights

  • Glycomine has raised $115 million in Series C funding to advance GLM101, a potential first-ever treatment for PMM2-CDG, a rare genetic disorder affecting glycosylation with no FDA-approved therapies.

  • The company plans to launch a randomized, placebo-controlled Phase IIb trial by mid-2024, enrolling 40-50 patients ranging from children to adults, with data expected by mid-2026.

  • GLM101 is a lipid nanoparticle-delivered mannose-1-phosphate replacement therapy that showed promising results in early Phase II trials, demonstrating improvements in ataxia symptoms among nine patients.

California-based biotechnology company Glycomine has secured $115 million in Series C financing to advance its lead candidate for a rare genetic disorder into pivotal clinical trials, the company announced Wednesday.
The funding will support the development of GLM101, a novel therapy targeting phosphomannomutase-2 congenital disorder of glycosylation (PMM2-CDG), the most common of hundreds of glycosylation disorders that currently have no FDA-approved treatments.

Understanding PMM2-CDG

PMM2-CDG is a genetic condition that disrupts glycosylation—the essential biological process of adding sugar chains to proteins. The disorder stems from mutations affecting the phosphomannomutase 2 protein, which plays a critical role in this process.
"We think it's maybe up to 15-20 thousand patients in the U.S. and Europe, which is a relatively large population for a rare disease," said Steven Axon, Glycomine's CEO, comparing the prevalence to that of Pompe disease.
The condition is typically diagnosed in infancy and presents with varied symptoms and severity. Most patients experience neurological dysfunction, language and motor difficulties, ataxia, seizures, immune dysfunction, and coagulation issues.
"PMM2 has a 20% mortality rate within the first five years of life, from organ failure and failure to thrive," Axon explained. "And glycosylation is at the core of all of those clinical signs."

Innovative Therapeutic Approach

GLM101 represents a novel approach to treating PMM2-CDG. The therapy delivers mannose-1-phosphate (M1P)—a molecule critically deficient in patients with the disorder—using lipid nanoparticle technology.
This delivery mechanism is crucial to the treatment's potential efficacy. According to Axon, the lipid nanoparticle vehicle extends M1P's half-life in the bloodstream from just a few minutes to approximately 80 hours, allowing for wide biodistribution throughout the body.
Unlike enzyme replacement therapies used for other rare disorders, GLM101 replaces a missing sugar molecule rather than an enzyme and aims to correct a defective chemical process instead of clearing accumulated toxins.

Clinical Development Progress

Earlier this year, Glycomine reported "encouraging" data from a Phase II trial of GLM101, demonstrating improvements in ataxia—a neurological symptom characterized by loss of muscle control—among nine adult and adolescent patients. Improvement in ataxia serves as the clinical endpoint for GLM101's efficacy studies.
With the new funding, Glycomine plans to launch a more rigorous Phase IIb trial by mid-2024. This randomized, placebo-controlled study will enroll 40-50 patients ranging from two years of age to adulthood, with data expected by mid-2026.
"The Series C round will carry the company through a more rigorous, randomized and placebo-controlled Phase 2b study," Axon said. "This will really tell us whether the effect we were seeing in the earlier clinical program has been confirmed."

Regulatory Outlook and Future Plans

Following the completion of the Phase IIb trial, Glycomine intends to engage with the FDA regarding potential approval pathways. While additional trials may be required, the company remains optimistic about regulatory discussions given the absence of alternative treatments for PMM2-CDG.
"We're hopeful for productive regulatory discussions," Axon stated. "We think we're in good shape with the FDA."
If the Phase IIb results prove positive, the company may explore partnership opportunities with larger pharmaceutical companies to support commercialization efforts.
"Having this randomized controlled data and really knowing that the drug works and its path to approval would be highly derisking for a pharma partner," Axon noted.

Beyond PMM2-CDG

While focusing primarily on GLM101 for PMM2-CDG, Glycomine is also investigating mRNA treatments to produce enzyme replacements for the disorder. Additionally, the company is developing drug candidates for other rare diseases, though specific details about these pipeline programs have not been disclosed.
The significant investment underscores the growing interest in developing treatments for rare genetic disorders with high unmet medical needs, particularly those affecting children and with no existing therapeutic options.
Subscribe Icon

Stay Updated with Our Daily Newsletter

Get the latest pharmaceutical insights, research highlights, and industry updates delivered to your inbox every day.

Related News

Sources

MedPath

Empowering clinical research with data-driven insights and AI-powered tools.

© 2025 MedPath, Inc. All rights reserved.