Does Derivative include Structural Analogues?
What is a derivative? Does derivative encompass compounds chemically similar to and synthesized from a known compound? Or does derivative also include structural analogues of a known compound? According to Oxford Advanced Learner’s Dictionary, ‘derivative’ is a word or thing that has been developed or produced from another word or thing, whereas ‘analogue’ is a thing that is similar to another thing. Giving plain dictionary meaning, a derivative is a compound chemically similar to and synthesized from a known compound, which mean that Erlotinib is a derivative of Gefitinib stands fallacious. But it would not be incorrect to state that Erlotinib is a structural analogue of Gefitinib.
In pharmaceuticals, often a new drug class is researched into a family of structural analogues sharing same chemical backbone structure, but such analogues are not necessarily derivatives of other analogue(s) in the same class. It would be absurd if word ‘derivative’ used under section 3(d) read to include structural analogues.
Is Erlotinib a selection invention? To be continue…