Inland Diamond won a Federal Circuit remand after a district court used issue preclusion to invalidate dependent patent claims following earlier IPR decisions.
The PTAB had found some related claims unpatentable but had not found the asserted dependent claims unpatentable. The district court treated the earlier Board rulings as enough to resolve obviousness against Inland.
The Federal Circuit vacated and remanded, making the case a useful boundary marker for how PTAB results carry into district-court invalidity disputes.
For litigants, the message is granular: an IPR loss can be powerful, but preclusion still depends on what was actually decided and whether the same issue is being relitigated.