In the final written decisions of two related inter partes reviews (IPRs), the U.S. Patent and Trademark Office’s Patent Trial and Appeal Board (PTAB) sided with the petitioner and canceled all claims under review.  Smith & Nephew, Inc. v. ConvaTec Technologies, Inc., Case Nos. IPR 13-00097 and IPR 13-00102 (PTAB, May 29, 2014) (Guest, APJ). 

The patents at issue were directed to methods of manufacture for enhancing the ability of silver-containing medical devices such as wound dressings to resist uncontrolled discoloration.  Each of the claims at issue required the devices to remain “substantially photostable” prior to rehydration.

After finding the claims at issue anticipated and obvious in view of the prior art, the PTAB considered ConvaTec’s assertion that secondary considerations precluded a finding that the claims were unpatentable. ConvaTec presented evidence of commercial success of its AQUACEL product as evidence of nonobviousness.  ConvaTec argued that its AQUACEL product “doubl[ed] the size of the market in the US within just two years.”  However, noting that commercial success must “derive[] from a feature recited in the claims” and that ConvaTec provided “no details of the manufacturing process” for its AQUACEL product, the PTAB deemed unpersuasive ConvaTec’s arguments regarding these method of manufacture claims.

The PTAB also denied ConvaTec’s motion to amend two of the claims at issue.  First, the PTAB noted ConvaTec’s failure to point to specific sections of the original disclosure for written description support as required by Rule 41.121(b)(1).  The PTAB concluded that Convatec’s reference to issued claims and portions of the issued patents (without indicating whether the issued specification was identical to the original disclosure) was not sufficient to satisfy the rule.  Second, the PTAB explained that ConvaTec must do more than simply explain why the proposed substitute claims were patentable over the grounds raised in the IPR.  The PTAB noted that a patent owner must also discuss other known prior art references, the level of ordinary skill in the art, and the knowledge possessed by one of skill in the art with respect to the new claim features.

In what may have been the first concurring opinion in a final written decision of the PTAB, APJ Snedden disagreed with the majority’s construction of the term “substantially photostable” but concurred with the majority’s ultimate decision of unpatentability.  The patents defined “photostable” as “[c]ontrolled colour change to a desired colour with minimal change thereafter.”  And while the majority concluded that a “desired colour” could be any color, APJ Snedden concluded that, in light of the evidence on the record, “desired colour” could not include purple, which is the color of silver after exposure to light.  According to APJ Snedden, purple discoloration was “undesirable for silverized medical devices meant for coming into contact with skin.”

*Article co-authored by Teri McClerklin