During the American Society of Gene & Cell Therapy (ASGCT) 24th Annual Meeting, which took place virtually from May 11-14, 2021, biotechnology company M6P Therapeutics (“M6P”) presented preclinical data relating to its gene therapy candidate M002. According to the news release, the data highlighted proof-of-concept data on how M002 could be potentially beneficial for patients with mucolipidosis type II (ML II).
M002
So what is M002? M6P developed M002 to address the company’s mission of helping patients with lysosomal storage disorders. The gene therapy was created using the company’s proprietary S1S3 bicistronic platform. Through this platform, M6P can modulate N-glycan processing, allowing the company to supplement lysosomal proteins with mannose 6-phosphate (M6P). Ultimately, this allows treatments to be more effectively delivered, creating more effective therapies overall.
During the presentation, researchers spoke about the gene therapy, delivered via AAV9. In the preclinical study, researchers administered M002 to mice models of ML II. Some findings included:
- Mice models of ML II who received M002 treatment saw improved sensorimotor activity.
- M002 treatment improved S1S3 expression throughout the body. For example, researchers saw increased activity in the salivary gland, heart, and liver.
- Less lysosomal enzymes were secreted in serum, though higher tissue levels occurred.
Mucolipidosis Type II (ML II)
Also known as inclusion-cell disease, mucolipidosis type II (ML II) is a rare, severe, and progressive metabolic disorder. GNPTAB gene mutations cause ML II. Ultimately, these gene mutations prevent the ability to add M6P to lysosomal enzymes. This prevents the body from moving lysosomes around and breaking down certain material within cells, causing a variety of health issues. Since ML II is inherited in an autosomal recessive pattern, an affected individual must inherit one defective gene from each parent.
Altogether, researchers estimate that 1 in 100,000-400,000 people have ML II. The condition equally impacts males and females. This debilitating disorder is often fatal and most patients do not survive past infancy or early childhood. Symptoms include:
- Constipation and/or diarrhea
- Frequent respiratory infections
- Gingival hyperplasia (overgrowth of gum tissue)
- Chronic ear infections, leading to hearing loss
- “Coarse” facial features
- Low muscle tone
- Hoarse voice due to vocal cord stiffening
- Physical, developmental, and cognitive delays
- A weak cry (in infancy)
- Spleen, liver, and heart valve enlargement
- Abdominal or umbilical hernias
- Short-trunk dwarfism
- Corneal clouding
- Scoliosis and other skeletal abnormalities
- Congestive heart failure
- Restricted joint movement
- Thick and tight skin
- Fused fingers
