Horizon Therapeutics plc Announces Short-Term TEPEZZA (teprotumumab-trbw) Supply Disruption Due to Government-Mandated (Operation Warp Speed) COVID-19 Vaccine Production

Horizon Therapeutics plc (Nasdaq: HZNP) announced that it expects a short-term disruption in TEPEZZA (teprotumumab-trbw) supply as a result of recent government-mandated COVID-19 vaccine production orders related to Operation Warp Speed that have dramatically restricted capacity available for the production of TEPEZZA at its drug product contract manufacturer, Catalent. Operation Warp Speed, per its authority provided through the Defense Production Act of 1950, recently ordered the prioritization of certain COVID-19 vaccine manufacturing at Catalent, resulting in the cancellation of previously guaranteed and contracted TEPEZZA drug product manufacturing slots in December, which were required to maintain TEPEZZA supply. To offset the reduced slots allowed by Operation Warp Speed and Catalent, the Company accelerated plans to increase the production scale of TEPEZZA drug product. The Company currently anticipates that this drug supply shortage will begin at the end of December and could last through the first quarter. The length of the TEPEZZA supply disruption will depend on whether future manufacturing slots are successfully completed as well as decisions by the U.S. Food and Drug Administration (FDA) regarding this increased scale manufacturing process of TEPEZZA. The Company expects to submit data in January from the first increased scale manufacturing lot to the FDA for its review and approval.

TEPEZZA is a biologic approved for the treatment of Thyroid Eye Disease (TED), which is a rare, serious, progressive and vision-threatening autoimmune disease.¹ There are no FDA-approved alternative treatments for TED.

“We appreciate the efforts Operation Warp Speed and the Administration are taking to accelerate the COVID-19 vaccine production to save lives and put an end to the pandemic,” said Tim Walbert, chairman, president and chief executive officer, Horizon. “We understand the impact that the TEPEZZA supply disruption will have on patients with TED and physicians who treat them. Our job is to support these patients and physicians and we will continue to work closely with the FDA and Operation Warp Speed to limit the length of this disruption and accelerate the availability of TEPEZZA drug product supply.”