Antibodies, large molecule drug

The following discussion addresses only small-molecule drugs, chemical compounds with molecular weights less than 1,000 Daltons. Large-molecule drugs (biologies) such as vaccines, cytokines, antibodies, and genes also can be studied by the methods of pharmacokinetics, but they are distributed and cleared in fundamentally different ways than small molecules. (3, 4). 

Among the currently FDA approved drugs for colorectal cancer, cetuximab and bevacizumab are large molecules (antibodies), the products of the biotechnology industry. The others are small molecules. 

Whole proteins, including monoclonal antibodies, are the fastest-growing class of therapeutics. Compared with traditional small molecule drugs, much additional analysis is necessary for their development and production due to their large size and complex structure. The protein construct and its formulation have to be optimized during development, and its structural integrity must be closely monitored during production. 

Antibodies are large molecules, so drugs can be conjugated without altering the binding properties ... 

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