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Molecular Weight

The molecular weight, \(MW\), is the molar mass of a drug. In the model, it is used to convert weight-based dose amounts (mg or mg/kg) to a number of molecules dosed. It is also used to convert weight-based drug concentration (ug/mL) to molar concentration (nM).

Molecular Weight in Assess

Molecular weight for protein-based drugs can be calculated based on protein sequence. For ADCs, the molecular weight is defined as the sum of antibody backbone molecular weight and the product of DAR and the payload molecular weight. For antibodies or antibody-like biotherapeutics, typical values can be estimated based on the structure. The typical molecular weight of an antibody is 150 kDa (Janeway et al.).

References

  • Janeway CA Jr, Travers P, Walport M, et al. Immunobiology: The Immune System in Health and Disease. 5th edition. New York: Garland Science; 2001. The structure of a typical antibody molecule. Available from: https://www.ncbi.nlm.nih.gov/books/NBK27144/