In a press release from March 3, 2021, biotechnology company BioMarin Pharmaceutical Inc. (“BioMarin”) shared that it had completed full enrollment for a Phase 2 clinical trial evaluating vosoritide for pediatric patients with achondroplasia. Altogether, the study will last for 52 weeks (approximately 1 year). 70 children aged 0-5 years old enrolled. As there are no current licensed treatments for achondroplasia, this could offer a new, less invasive, and more accessible treatment option.

Vosoritide

Currently, most treatment options available for patients with achondroplasia require surgery. However, this can be invasive, painful, and not accessible for all families. Vosoritide offers a potential option to fill this unmet need. According to BioMarin, vosoritide is:

an investigational analog of C-type Natruiretic Peptide (CNP)…being tested in children whose growth plates are still “open.”

An estimated 25% of patients with achondroplasia still have these “open” growth plates. Vosoritide would be administered daily via an injection if approved. It would work by stopping the medical processes and pathways which inhibit bone growth, allowing patients to grow to a “normal” stature.

Thus far, vosoritide received Orphan Drug and Priority Review designations.

The Trial

Within the clinical trial, researchers will evaluate the safety, efficacy, and tolerability of vosoritide. Additionally, the trial seeks to understand how vosoritide would beneficially impact bone growth in infants or children with achondroplasia. Following the Phase 2 trial, all participants will have the option to enroll in an extension trial. Rather than receiving either vosoritide or a placebo, all those in the extension trial will receive vosoritide. Outside of the data in the trial, researchers hope to understand how vosoritide might impact quality of life (QOL), sleep disturbances, body proportion, and other elements.

Achondroplasia

FGFR3 gene mutations cause achondroplasia, a bone growth disorder that causes dwarfism, defined as short stature as an adult. Achondroplasia means “without cartilage formation,” and the condition is aptly named. Normally, FGFR3 helps the body make a protein that plays a role in bone growth. But when these mutations occur, cartilage does not properly ossify (convert to bone), altering skeletal development. In many cases, these gene mutations are spontaneous rather than inherited. Achondroplasia is the most common form of disproportionate dwarfism.

Symptoms and characteristics of achondroplasia include:

• A short stature with short arms and legs but a normal-sized torso
• Short fingers
  • In patients with achondroplasia, the ring and middle fingers may point away from each other.
• Large, broad forehead
• Scoliosis (abnormal spinal curvature)
• Obesity
• Frequent and chronic ear infections
• Spinal stenosis (spinal narrowing)
  • This can cause pressure on the spinal cord and nerves.
• Hydrocephalus (fluid build-up within the brain)
• Difficulty bending elbows
• Curved or bowed legs
• Back pain
• Apnea (periods of slowed or stopped breathing)
• Low muscle tone

Learn more about achondroplasia.