Prosecution Laches as Defense to Infringement — Cancer Res. Tech. Ltd. v. Barr Labs., Inc.

Prosecution laches is an equitable defense to a charge of patent infringement, that “may render a patent unenforceable when it has issued only after an unreasonable and unexplained delay in prosecution” that constitutes an egregious misuse of the statutory patent system.

Obviousness in prodrugs — Daiichi Sankyo Co. v. Mylan

Proof of obviousness based on structural similarity requires clear and convincing evidence that a medicinal chemist of ordinary skill would have been motivated to select and then to modify a prior art compound (e.g., a lead compound) to arrive at a claimed compound with a reasonable expectation that the new compound would have similar or improved properties compared with the old.