Start Candy Lands $115 million in Clinical Trials for Ultra Rare Diseases with Unapproved Drugs

The journey of people with rare diseases and their families may be a long-term featured by misdiagnosis, so it is also true for those with ultra-rare diseases with the abbreviation PMM2-CDG. Startup Glycomine CEO Steven Axon said the enzyme deficiency can cause muscle problems and delayed development, which are often mistaken for other diseases.

PMM2-CDG is hereditary, but is not currently part of neonatal screening. The disease can be diagnosed with genetic testing, but doctors need to know how to test it. If the patient does not see a clinician familiar with PMM2-CDG, the journey of diagnosis may be one year or more. The most common misdiagnosis is cerebral palsy.

“If they were born before 1995, they might still believe they had cerebral palsy because this is when the PMM2 protein was identified as the culprit for the disease,” Axon said. “But for other patients, they will face various challenges early on, so they will face challenges with the liver, the increase in liver enzymes, and they will not be able to thrive. So they will see experts and try to understand.”

Disease lack of enzymes with the same name can cause problems throughout the body. The most common cause of death is organ failure. In addition to supportive care, there is no medication for PMM2-CDG. Candy is developing a drug that uses a novel approach to use for enzyme deficiency. On Wednesday, San Carlos, California-based Biotech announced $115 million in new financing for mid-term clinical testing.

PMM2-CDG is the abbreviation for 2-glycosylation diseases of amino phosphate nuclease. The lack of PMM2 enzymes stems from mutations in the PMM2 gene that disrupts glycosylation, the process by which sugar chains are linked to proteins. The PMM2 enzyme is needed to convert a certain compound into mannose-1-phosphate, a compound that is crucial for this process.

Glycoproteins formed by glycosylation are the key to the functions of various tissues and organs in the entire human body. Axon says humans suffer from about 10,000 glycosylated proteins, all of which may be affected by PMM2-CDG. Ataxia, loss of muscle coordination is the most common manifestation of PMM2-CDG. Seizures, developmental delays, and cognitive challenges are common in the disease, and candy is estimated to affect between 10,000 and 15,000 people in the United States and Europe.

For many rare enzyme deficiency, treatment is usually enzyme replacement therapy. But the glycoform did not try to replace the PMM2 enzyme. The company's drug candidate is code GLM101, which is a replacement for Mannose-1-phosphate. Axon said the reason for this approach is the nature of the disease. Enzyme substitution is often used for lysosomal storage disorders, requiring enzymes to clear away toxic diseases. This is not the case with PMM2-CDG. Therefore, it is much easier to provide mannose-1-phosphate than to provide insufficient enzymes.

The challenge is to deliver mannose-1-phosphate in the body. Without protection, the body breaks down molecules in about five minutes — not enough time to get to where any help is needed, Axon said. Glycosides encapsulate mannose 1-phosphate in lipid nanoparticles, extending the cycle half-life of their drug to about 80 hours. It is managed weekly via intravenous fluids, which takes about three hours, although the company is making changes to reduce the time it takes to dosage.

“We offer that week every week because many of the proteins we are interested in flip over in a few days,” Axon said. “We have an extended half-life, but by the end of the week of the drug, we are already below the exposure level we want to reach, so we need to supplement that.”

The science behind Glm101 was developed within Glycomine, a Bay Area scientist founded in 2014 and supported by friends, family and seed money. Five years later, Glycyrrhizin shut down its $68 million Series B round and headed to the clinic.

So far, glycosides have been tested in 10 patients in the open-label phase 2 study. To date, data from four adults and five adolescents at six months were statistically significant and clinically significant in ataxia based on the score scale used to assess this symptom. Furthermore, the drug appears to be safe and tolerant.

With the encouraging early results, Candy is undergoing a six-month placebo-controlled 2B test aimed at recruiting participants aged 4 to 40 years old. Like open-label studies, evaluating ataxia will also be the target of placebo-controlled clinical trials. But six months later, those receiving the placebo will cross the treatment department, and all patients will follow in a long-term extended study. Axon expects enrollment in Phase 2B will begin in the middle of this year. Preliminary data may appear in mid-2026. He added that the study was intended to potentially support regulatory submissions, but the decision still requires FDA signatures.

Axon said GLM101 can be used to treat other glycosylation diseases, but these diseases are even rarer than PMM2-CDG and affect a small number of patients, making development difficult. Candy has not yet made these signs. However, methods of distributing a wide range of payloads across the body using lipid nanoparticles may be suitable for other diseases. Candy is exploring such applications, but disease targets are still not disclosed.

Ganti is not the only company developing PMM2-CDG treatment. This rare disease is one of the targets for applying the therapeutic drug candidate Govorestat. However, the biotech is currently focusing on the drug’s galactosemia, a different rare disease without FDA-approved treatment. Last fall, the FDA rejected Applied's application to seek regulatory approval in this direction. According to the company's investigation application, in PMM2, the applied small molecules have been tested in clinical trials initiated by researchers.

Glycomine's Series C financing was announced Wednesday, led by a fund managed by CTI Life Sciences Fund, ABRDN Inc. and Advent Life Sciences. These investors joined earlier investors Sanderling, Novo Holdings, Sanofi Ventures, Abingworth, Rivervest Venture Partners, Chiesi Ventures, Remiges Ventures and Asahi Kasei Ventures.

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