The research-grade biosimilar antibody is a fully human IgG1 monoclonal antibody that binds to and inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9), an enzyme that has "gain-of-function" mutations in autosomal dominant hypercholesterolemia. PCSK9 is secreted by the liver and binds to the LDL receptors in serum and marks them for lysosomal degradation. As a result, the LDL receptors are unable to recycle to the plasma membrane, thus reducing their binding to LDL-C and subsequent clearance of LDL-C from plasma. Therefore, by binding to free PCSK9, the biosimilar allows more LDL-C reuptake by the liver and facilitates a higher rate of clearance of LDL-C. The original drug received approval from the FDA as a second-line of treatment for heterozygous familial hypercholesterolemia in adults, whose LDL-C was not controlled by the combination of diet and statin treatment.
In PBS, pH 7.5