Asfotase alfa, sold under the brand name Strensiq, is a medication used in the treatment of people with perinatal/infantile- and juvenile-onset hypophosphatasia.The most common side effects include injection site reactions, hypersensitivity reactions (such as difficulty breathing, nausea, dizziness and fever), lipodystrophy (a loss of fat tissue resulting in an indentation in the skin or a thickening of fat tissue resulting in a lump under the skin) at the injection site, and ectopic calcifications of the eyes and kidney.The enzyme tissue non-specific alkaline phosphatase (ALP) plays a key role in creating and maintaining healthy bones, and managing calcium and phosphate in the body. People with hypophosphatasia cannot make enough working ALP, which leads to weak bones. Asfotase alfa is a version of the human ALP enzyme and serves as a replacement, thereby increasing levels of working ALP. Medical uses
In the United States, asfotase alfa is indicated for the treatment of people with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP).In the European Union, asfotase alfa is indicated for long-term enzyme replacement therapy in people with paediatric-onset hypophosphatasia to treat the bone manifestations of the disease. Adverse effects
The most common adverse effects in studies included injection site reactions (pain, itching, erythema, etc. ), headache, limb pain, and haematoma. Possible rare side effects could not be assessed because of the low number of patients. Interactions
Asfotase alfa interferes with alkaline phosphatase measurements. As asfotase alfa is a glycoprotein (as opposed to a small molecule), no relevant interactions via the cytochrome P450 liver enzymes are expected.
In comparison, approximately 20 percent of control participants had growth delays over time, with shifts in height or weight from the normal range for children their age to heights and weights well below normal for age. Juvenile-onset participants also showed improvements in bone mineralization, as measured on a scale that evaluates the severity of rickets and other HPP-related skeletal abnormalities based on x-ray images. All treated participants demonstrated substantial healing of rickets on x-rays while some natural history control participants showed increasing signs of rickets over time. References
External links
"Asfotase alfa". Drug Information Portal. U.S. National Library of Medicine.