As such, inventors of therapeutic biologics will be under greater pressure to delay the filing of patent applications, to avoid starting the patent clock prematurely. A patent application can be delayed one year by the filing of a provisional patent application, which serves as a placeholder for one year without starting the 20-year clock. Companies may also need to consider waiting longer to file patent applications on biologics, to give them more time to advance the FDA process.
On the other hand, the benefits of delaying patent protection must be weighed against the risks of later filing, including inadvertent disclosure of the invention to third parties or intervening discoveries by third parties that could hinder or prevent patent protection. If patents on the biological product expire too soon, dosing or formulation improvements developed during clinical trials may offer the only meaningful opportunities for patent protection.
Patent terms can be increased if the USPTO fails to meet certain deadlines in examining a patent application (patent term adjustment), an increase that can be partially or completely forfeited by delays introduced by patent applicants. Patent terms can also be extended to compensate an applicant for delays in the FDA approval process (patent term extension). However, the enforceable rights during the period of patent term extension may be limited in scope to the approved product, without covering other biosimilars.
Indeed, because biosimilars can differ from a reference product, the scope of any patent protection is important. Traditional generic pharmaceuticals have the same chemical structure as a branded pharmaceutical, so a patent that covers a branded pharmaceutical will normally also cover a corresponding generic. Not so with biosimilars! Even an interchangeable biosimilar can be different from the reference product, as long as it is expected to produce the same clinical result. The FDA has yet to indicate how different interchangeable amino acid sequences may be.
The courts recently made it harder to claim therapeutics broadly (see Ariad v. Lilly as just one example). Companies looking to enter the biosimilar market can target the sweet spot of proteins similar enough to be interchangeable with a reference product but different enough to escape the scope of any patent protection. On the other hand, current inventors can focus on obtaining patents that cover the range of variants expected to produce the same clinical result.
The biosimilar legislation will spur new competition for biologics—and new patent strategies for addressing the changing competitive landscape.