USPTO Proposes Changes to Terminal Disclaimer Practice

On May 10, 2024, the US Patent and Trademark Office (USPTO) introduced a proposed rule that could have significant implications for patent procedures, particularly concerning terminal disclaimers used to address rejections based on non-statutory double patenting. According to the proposal, a terminal disclaimer must now include a provision stipulating that the patent will be unenforceable if it is linked directly or indirectly to another patent whose claims have been invalidated due to prior art. This new condition, if enacted, would supplement existing requirements aligning the expiration dates of disclaimed patents with referenced ones and restricting enforcement to periods of common ownership.

This proposed rule marks a substantial departure from current practice, which typically assesses claims individually, even within a single patent. It shifts the balance of influence towards challengers of patents and undermines the presumption of validity granted by statute.

For patent applicants and owners, these proposed changes present challenging decisions. Adhering to the new requirements in terminal disclaimers means accepting the risk that the enforceability of an entire patent could depend on the validity of a single claim in another patent. Consequently, applicants may be more inclined to contest double patenting rejections or seek other claim amendments instead of merely filing a disclaimer.

The proposed rule could also influence broader patent filing strategies. Applicants might become more cautious about submitting continuation applications with minor variations, opting instead for more distinct inventions. There may also be a tendency to include claims of varying scope in initial applications to avoid the need for follow-on patents or to provoke a restriction requirement that sidesteps the issue of obviousness-type double patenting.

Finally, the new rule would encourage patent applicants to welcome restriction requirements in order to benefit from the safe harbor provision of 35 U.S.C. 121, which protect divisional applications against double patenting rejection and the need for terminal disclaimers.