Nature Outline |


Some of the most effective new pharmaceutical drugs are highly complex biological molecules. To make such therapies less expensive and more broadly available, drug developers seek to fashion biosimilars — good-enough copies that can be produced at large scale.

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Biosimilars: complex copycat drugs

The patents on many well-known biological drugs will soon expire, giving drug developers the opportunity to make generic versions. Making an exact copy of these large, complex molecules, which include monoclonal antibodies, is almost impossible. But if developers can create similar versions (biosimilars) that can pass stringent tests, these important medicines could become available to many more people worldwide.