Is the Claimed Stent Described in the Specification?

The U.S. Court of Appeals for the Federal Circuit upheld a summary judgment determination that the asserted claims of four patents were invalid for failing to comply with the written description requirement of §112, ¶1.   Although the district court also found that the asserted claims were invalid for lack of enablement, the Federal Circuit did not reach that issue on appeal.  Boston Scientific Corp. v. Johnson & Johnson, Case Nos. 10-1230, -1231, -1233, -1234 (Fed. Cir., June 7, 2011) (Moore, J.) (Gajarsa, J., concurring-in-part). 

The patents-in-suit derived from applications related to drug-eluting coronary stents used in the treatment of coronary artery disease.  The challenged claim language in all the patents had been added during prosecution after a competitor received European approval to sell a drug-eluting stent containing everolimus.

Three of the patents shared a common specification and generally claimed drug-eluting stents utilizing “rapamycin, or a macrocyclic lactone analog thereof” as a therapeutic agent.  The specification, however, contained virtually no information regarding macrocyclic lactone analogs of rapamycin.  To the contrary, the specification failed to disclose any formulae or structures of any specific analog or provide any definitions, examples or experimental models for determining whether a compound is a structurally similar analog of rapamycin. After the district court granted summary judgment that the claims were invalid for lack of written description Johnson & Johnson appealed.

In its de novo review, the Federal Circuit rejected the patentees’ argument that the description of macrocyclic lactone analogs was sufficient to satisfy the written description requirement as of the filing date since there was evidence that were a few macrocyclic lactone analogs known in the prior art at the time of filing.  Citing Ariad Pharm, Inc. v. Eli Lilly and Co., (see IP Update, Vol. 13, No. 4) the Court reiterated that “a sufficient description of a genus requires the disclosure of either a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one skilled in the art can ‘visualize or recognize’ the members of the genus.”   The Court concluded that due to the structural complexity of rapamycin, the lack of existing knowledge in the field at the time of filing and the unpredictability of the art, the specification did not adequately describe the tens of thousands of possible macrocyclic lactone analogs that the patents claimed. 

The fourth patent claimed “rapamycin or a macrocyclic triene analog thereof” in combination with specific drug-eluting stents.   This patent disclosed a genus (analogs of rapamycin), but claimed a narrower sub-genus (macrocyclic triene analogs of rapamycin) that was not disclosed ipsis verbis in the specification.  The Court held that in such a situation, simply describing a large genus of compounds is not sufficient to satisfy the written description requirement as to particular species or sub-genuses where the specification lacks blaze marks to indicate compounds that might be of special interest besides those disclosed as preferred.  The Court concluded that due to the lack of information in the patent and the nascent state of using drug-eluting stents at the time of filing, no reasonable juror could have determined that the specification reasonably conveyed to persons skilled in the art that the inventor had possession of the claimed sub-genus. 

Practice Note:   As this edition of IP Update goes to press, Johnson & Johnson has petitioned the Federal Circuit for a rehearing or rehearing en banc, seeking clarification as to how much prior art information must be disclosed in a patent to satisfy the written description requirement.