As Sandoz gears up to launch one of the most anticipated biosimilars of the year, the company could face near-term competition thanks to a new agreement between Amgen and Celltrion.
Late last week, Amgen said it had reached a settlement with Celltrion, putting a bout of patent litigation to bed and allowing the South Korean company to launch its biosimilar versions of Amgen’s bone blockbusters Prolia and Xgeva (denosumab) as early as June 1.
As part of the agreement, Celltrion acknowledged that the denosumab patents it challenged were valid and infringed by the company’s biosimilar candidates in the U.S.
The settlement appears to mark the second of its kind following a similar accord between Amgen and Sandoz last spring. Under that prior agreement, Sandoz received the all-clear to launch copycats of Prolia and Xgeva in the U.S. on May 31 of this year, or earlier “under certain limited conditions.”
Sandoz won FDA approval for its Prolia and Xgeva biosimilars—dubbed Jubbonti and Wyost—last March. Aside from being the first U.S.-approved biosimilars to Amgen’s denosumab franchise, Sandoz’s Jubbonti and Wyost are also interchangeable, which means they can be subbed in for their reference products without prescriber approval, much like the process for dispending small molecule generics.
As for Celltrion, the company has yet to win an FDA green light for its Prolia and Xgeva copycats, which go by the names Stoboclo and Osenvelt, respectively. The company said in Nov. 2023 that it had submitted its biosimilar application to the FDA, according to a Business Korea report at the time.
Elsewhere, Stoboclo and Osenvelt have received regulatory endorsements in the European Union and Korea.
Amgen’s Prolia and Xgeva were initially approved in 2010 to treat osteoporosis and skeletal weakening in patients with bone metastases from solid tumors, respectively. Both therapies leverage the RANK ligand inhibitor denosumab but diverge in terms of indications, strengths and dosing intervals.
Prolia generated $2.1 billion in the U.S. during the first three quarters of 2024, while Xgeva brought home around $1.1 billion over that same stretch. Both drugs are set to lose protection from a key U.S. patent in February, according to Amgen’s most recent annual report.
While Sandoz appears poised to hit the scene with its biosimilars first, the fact that Celltrion holds claim to the next launch window while lacking an FDA approval somewhat muddies the waters in terms of overall launch staging for off-brand denosumab.
Apart from Sandoz and Celltrion, Organon, Teva, Fresenius Kabi and Samsung Bioepis have also filed applications for Prolia and Xgeva biosimilars with the FDA. As of October, Amgen had filed patent infringement lawsuits against Sandoz, Celltrion, Samsung Bioepis and Fresenius Kabi over their proposed copycats, online sources show.
Should Celltrion ultimately win approval for Stoboclo and Osenvelt in the U.S., the company may launch with a marketing edge thanks to a prior tie-up with retailer juggernaut Costco.
Last summer, Celltrion revealed that its approved biosimilar to Humira had been added to the Costco Member Prescription Program—a drug discount card program that helps eligible Costco members and their dependents access certain drugs.