Committee Reports

Minerva Surgical v.Hologic Brief for The New York City Bar Association as Amicus Curiae in Support of Neither Party


The Patents Committee, with support from the Council on Intellectual Property, filed an amicus brief in the United States Supreme Court in Minerva Surgical, Inc. v. Hologic, Inc. (No. 20-440). Assignor estoppel in patent law is currently applied as a bright line rule that prevents anyone who assigns a patent—and anyone in privity with the assignor—from later challenging the validity of that patent in federal court. In the brief, the City Bar argues that this view of the doctrine is overbroad and should be curtailed. First, the rationale for broad assignor estoppel has been significantly undermined by changes made by the America Invents Act so that inventors no longer attest to the novelty of the invention. Second, the doctrine was originally crafted by close analogy to real property law, but the strength of this analogy has been lessened by recent case law. Third, the economic reality of today’s innovative environment is that most patent applications are filed by corporations that hold assignments from inventors under an obligation to assign, which weakens any imputation of estoppel. Fourth, public policy in favor of a dynamic innovation economy supports the ability to bring patent challenges by those best suited to do so. Additionally, inconsistent results have been seen under the current doctrine, because while this broad estoppel is applied in federal court, no estoppel applies before the USPTO’s Patent Trial and Appeal Board (PTAB). Consistent with the equitable nature of the doctrine, assignor estoppel should not apply as a bright line rule but should instead depend on the specific circumstances surrounding the patent assignment.