Secondary patents in the pharmaceutical industry: missing the wood for the trees?

The critics of the Innovator pharmaceutical industry allege that secondary patents are trivial modifications over the primary patent, which extend its term and delay the entry of the generics in the market place. The protagonists regard secondary patents a result of continuous research and development (R&D), which help them introduce and protect new, differentiated products.

The areas covered are Product life cycle management (PLCM), Drug approval process, Orange book (OB) listed patents, US patent data.

Our analysis of the patents and products of four innovators viz., AstraZeneca, Takeda, Eisai and Wyeth in the field of proton pump inhibitors (PPI's) and Merck and Pfizer in the field of Statins shows that secondary patents help innovators sustain competition against other innovators in the specific product segment. The number of secondary patents listed in OB per NCE depends on the innovators interest in exploiting the NCE, the success of R & D effort and product lifecycle management strategy in the wake of market competition. Market entry decisions of innovators are strategic rather than a mere fallout of the secondary patents granted. Entry of another innovator is more unpredictable and hurts the first entrant more vis a vis the entry of generics who can enter the market when the patents protecting a product are no more enforceable, and hence more predictable. Generic entry in the field of PPI's shows that the term of the primary patent is not extended by the secondary patents.