Genentech filed a patent infringement suit against Eli Lilly just hours after Genentech was granted a patent for a drug that’s been on the market for nearly two years.

Genentech claims that Lilly’s drug Taltz, an injection designed to treat psoriatic arthritis, infringes on Genentech’s patent because its active ingredient is ixekizumab, a humanized monoclonal antibody that works by inhibiting the immunology pathway IL-17.

Genentech’s patent for ixekizumab took effect at midnight on July 3; the lawsuit was filed in federal court for the Southern District of California within hours. The suit demands royalties and damages from Lilly but doesn’t seek a permanent injunction.