The FDA on Friday approved the first U.S. biosimilar of Humira (adalimumab), AbbVie’s best-selling biologic for treatment of inflammatory conditions. The biosimilar, Amgen’s Amjevita (adalimumab-atto), received approval for all of the indications requested by Amgen: in adults, moderately to severely active rheumatoid arthritis, active psoriatic arthritis, active ankylosing spondylitis, moderately to severely active Crohn’s disease, moderately to severely active ulcerative colitis, and moderate to severe plaque psoriasis, and in patients four years of age and older, moderately to severely active polyarticular juvenile idiopathic arthritis. Amjevita is the fourth FDA-approved biosimilar in the U.S. As noted by the FDA, Amjevita has been approved as a biosimilar of Humira, not an interchangeable product. Amgen also submitted its Humira biosimilar for review by the European Medicines Agency in December 2015, but the EMA has yet to issue a decision.

Amgen’s product is the subject of recently filed biosimilar litigation in the District Court of Delaware. In its August 4 complaint, AbbVie seeks to enjoin Amgen from manufacturing and marketing Amjevita, and asserts infringement of ten patents in its Humira patent estate. AbbVie states that scores of other patents are infringed but that it was limited by Amgen to asserting only ten of its patents in the immediate patent litigation phase of the Biologics Price Competition and Innovation Act of 2009 (BPCIA). In addition to its infringement claims, AbbVie seeks an order compelling Amgen to comply with the notice of commercial marketing provision of the BPCIA. Amgen answered and asserted counterclaims of noninfringement and invalidity for the ten asserted patents. Amgen also states that, contrary to the allegations in AbbVie’s complaint, it will follow the BPCIA by providing a 180 days’ notice of commercial marketing after its product is approved and that it therefore will not enter the market for at least 180 days after FDA approval. Amgen also accuses AbbVie of not abiding by the pre-suit litigation provisions of the BPCIA. The parties are scheduled to appear before Judge Robinson for a scheduling conference on October 27.