Immunex Corp. v. Sandoz Inc.


Issue(s) Presented

1. “Whether the patents-in-suit are invalid for [obviousness-type double patenting], where Immunex— which owns all substantial rights in those patents, including the ability to control patent prosecution—had already obtained earlier-expiring patents claiming obvious variants of the same inventions.” 2. “Whether the claims-in-suit are invalid for lack of written description, where the original specification did not disclose the key claimed features of etanercept and Immunex had to amend the specification to add them.” 3. “Whether the district court’s ruling on obviousness was infected by legal error.”


1. “We conclude only that where one of the rights transferred is the right to prosecute the patent at issue, identification of the effective “patentee” is informative in evaluating whether the patents are “commonly owned” for purposes of obviousness-type double patenting. Where, as here, a party ultimately controls prosecution of both sets of patents, the “all substantial rights” test aids in preventing the unjustifiable issuance of claims that are patentably indistinct from claims already owned by that party. Under these circumstances, looking to the “all substantial rights” test achieves the proper balance between deterring gamesmanship in prosecution, on the one hand, and avoiding any chilling effect on routine collaborations and licensing between parties working in the same field of research, on the other.”

2. “[W]e conclude that the district court did not err in finding that the priority application disclosed and demonstrated possession of full-length p75. Accordingly, we conclude that the district court’s written description analysis is not clearly erroneous.”

3. “We conclude that the district court’s analysis regarding motivation to combine was not legally erroneous because the treatment of illnesses that involve TNF is a stated objective of the claimed invention; the arguments at trial were focused on therapeutic effects of the claimed invention (and not on their benefits as diagnostic and research tools); and at least two of the asserted claims are directed to pharmaceutical compositions.”

“We have considered the parties’ remaining arguments and find them unpersuasive. For the foregoing reasons, we affirm the district court’s judgment that Sandoz has not shown that the patents-in-suit are invalid. “