In a decision last month, the Court of Appeals for the Federal Circuit gave petitioners in AIA proceedings yet another weapon to invalidate patents – by affirming a Patent Trial and Appeal Board (PTAB) decision that relied, at least in part, on new evidence introduced by the petitioner in its reply brief. (Genzyme Therapeutic Products LP v. BioMarin Pharmaceutical Inc., Fed. Cir. No. 15-1720).

Writing for a three-judge Fed. Cir. panel, Judge William C. Bryson said it should be expected that petitioners will introduce new evidence during the course of an Inter Partes Review (IPR) proceeding. Judge Bryson dismissed the notion that the record of an IPR is essentially closed following the PTAB’s institution decision.

“There is no requirement either in the board’s regulations, in the [Administrative Procedures Act] or as a matter of due process for the institution decision to anticipate and set forth every legal or factual issue that might arise in the course of the trial,” according to Judge Bryson.

Genzyme had argued that it was impermissible for the PTAB to relied on different evidence than the evidence relied upon in the institution decision.

“Genzyme’s argument that the institution decision must refer to every bit of evidence that is relied on by the board in its final written decision reflects a misunderstanding of the role of the institution decision in inter partes review proceedings before the board,” said the judge.

The opinion draws a distinction between new grounds for invalidity and new evidence that supports the grounds on which the trial was initiated. According to Judge Bryson, if the PTAB decision is based on the same grounds, due process is satisfied as long as the opposing party is notified and given a chance to respond.

The issue in the Genzyme case was whether two patents relating to treatments for Pompe’s disease were invalid. Petitioner, Biomarin, had presented two published prior art in vitro studies as evidence that Genzyme’s treatments were obvious. In Patent Owner’s Response, Genzyme argued that in vitro studies would not have been predictive to a person skilled in the art of results in humans. In its reply Biomarin introduced further published prior art in vivo studies that bolstered its obviousness argument.

While the Federal Circuit panel concluded that the PTAB decision was correct whether it relied upon either the in vitro or the in vivo studies, Judge Bryson made it clear that the in vivo studies were fair game for the PTAB’s final decision-making. “Because the institution decision comes at the outset of the proceedings and the patentee is not obligated to respond before the board makes its institution decision, it is hardly surprising that the board cannot predict all the legal or factual questions that the parties may raise during the litigation,” Judge Bryson wrote.

The Genzyme decision should caution Patent Owners in AIA proceedings not to rely solely on procedural objections to new evidence (e.g., via motions to exclude) but to also address the substance of the new evidence. It remains to be seen how effective Patent Owners will be in refuting new evidence because the only vehicle typically available to a patent owner following a petitioner’s reply is to cross-examine petitioner’s reply expert (assuming their is one). The only other option would appear to be requesting an opportunity to file a Surreply, which would require PTAB permission — a permission that can granted or denied in the board’s discretion.