A bill to address patent thickets.

S 3583 (A bill to address patent thickets) limits patent holders from asserting multiple patents against generic drug and biosimilar manufacturers in infringement lawsuits. It restricts a plaintiff to one patent per "Patent Group" (defined as commonly owned patents that avoid double patenting) when suing companies developing generic drugs under FDA's 505(b)(2)/505(j) pathways or biosimilars under PHS Act 351(k). The bill prohibits filing additional lawsuits for the same Patent Group against the same generic or biosimilar company. This directly affects pharmaceutical companies developing affordable alternatives and patent holders seeking to enforce patents against them.