For two years, Amgen Inc. has argued that “shall means shall” – and that when the Biologics Price Competition and Innovation Act says biosimilar drug applicants “shall” engage in the so-called patent dance, failure to do so can be enforced by an injunction that blocks the launch of their product.

On Monday, Amgen finally found a court that agreed – kind of. The U.S. Supreme Court ruled that the patent dance might be mandatory, but that it’s up to state law to determine whether and how to enforce it. “The mandatory or conditional nature of the BPCIA’s requirements matters only for purposes of California’s unfair competition law, which penalizes ‘unlawful’ conduct,” Justice Clarence Thomas wrote for a unanimous court in Sandoz v. Amgen.