By Counterforce Health Team —

Understanding Strensiq (Asfotase Alfa): A Treatment for Hypophosphatasia

Strensiq (generic name: asfotase alfa) is a prescription medication used to treat hypophosphatasia (HPP) — a rare, inherited metabolic disorder that affects bone development and strength. Approved by the FDA in 2015, Strensiq was the first enzyme replacement therapy specifically designed to target this condition.

What Is Hypophosphatasia?

Hypophosphatasia is caused by mutations in the ALPL gene, which leads to low activity of an enzyme called alkaline phosphatase. This enzyme is essential for bone mineralization — the process by which bones become hard and strong.

Without enough alkaline phosphatase, patients can experience:

  • Soft or weak bones
  • Bone pain or fractures
  • Dental problems
  • Muscle weakness
  • Difficulty walking or delayed motor skills (especially in infants and children)

How Strensiq Works

Strensiq is a recombinant enzyme replacement therapy that provides a synthetic version of alkaline phosphatase. By replacing the missing enzyme, Strensiq helps restore normal bone mineralization and improve overall bone health.

This treatment is designed to slow or reverse bone damage, reduce symptoms, and improve quality of life for patients with HPP.

How It’s Given

Strensiq is administered by subcutaneous injection (under the skin), usually several times per week. The exact dose and schedule depend on the patient’s age, weight, and severity of disease.

Because treatment is ongoing, patients and caregivers often receive training on how to perform injections safely at home.

Common Side Effects

Strensiq is generally well tolerated. Common side effects may include:

  • Injection site reactions (redness, swelling, or pain)
  • Fatigue
  • Headache
  • Muscle pain
  • Irritation around the eyes (in some cases)

Your healthcare provider will monitor your progress and adjust treatment as needed.

Benefits of Strensiq

Clinical studies have shown that Strensiq can:

  • Improve bone mineralization and strength
  • Reduce bone pain and fractures
  • Support better growth and motor development in children
  • Enhance mobility and overall quality of life

For many patients, Strensiq offers significant hope for managing this challenging condition.

Final Thoughts

Strensiq (asfotase alfa) is a groundbreaking therapy that addresses the root cause of hypophosphatasia. If you or your child has been diagnosed with HPP, talk to your doctor about whether Strensiq might be an appropriate treatment option.