Horizon's Tepezza supply dwindles as manufacturer Catalent pivots to Warp Speed vaccines

Horizon's thyroid eye disease med Tepezza will run scarce from the end of December into 2021, the company said Thursday, blaming COVID-19 vaccine orders that are dominating the agenda at contract manufacturer Catalent.

The Operation Warp Speed vaccine program recently ordered Catalent to prioritize pandemic vaccine manufacturing, citing the Defense Production Act of 1950, which allows the government to commandeer production in emergencies. Catalent then canceled Tepezza manufacturing slots this month, Horizon said in a release. 

Horizon has a contract for capacity at Catalent's Bloomington, Indiana site, which handles drug substance biomanufacturing, fill-finish services, device assembly, packaging and more, a Horizon spokesperson said over email. 

It's unclear which vaccine Catalent's been ordered to prioritize. Moderna, which is up for a vaccine nod as early as this week and recently doubled the size of its vaccine supply deal with the U.S., has a fill-finish deal with Catalent at the Bloomington site. Johnson & Johnson, still in phase 3 with its shot, also has an agreement with the CMO for capacity at the site. 

A Catalent spokesperson couldn’t confirm the specific vaccine at play. As the CMO works with clients, regulators and Operation Warp Speed to prioritize several pandemic drugs and shots, it's looked to ease manufacturing disruptions by revising plans and hammering out altered timelines with customers, the spokesperson said, adding, “Catalent and Horizon are working closely to alleviate scheduling issues.”

The Warp Speed move has "dramatically restricted capacity available for the production of Tepezza"—a drug with no FDA-approved alternatives, the company said.

To compensate, Horizon plans to move quickly on its plans to upsize each Tepezza manufacturing lot at Catalent, which would require FDA approval. The drugmaker plans to submit that data in January. Meanwhile, the company is working to recruit a second contract manufacturer, the Horizon spokesperson said.

The shortage is likely to begin later this month and last through 2021's first quarter, depending on the availability of future manufacturing slots and approval for Horizon's upsized production scale, the company said. 

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Beginning Dec. 17, the company is delaying new patient starts on the drug to preserve what supply is available for current Tepezza patients until it runs out. Horizon plans to keep in touch with those patients and their doctors, aiming to resume any interrupted therapy as soon as possible.

The shortage will force Horizon to postpone a Tepezza trial in chronic thyroid eye disease and an exploratory study in diffuse cutaneous systemic sclerosis until 2021's second quarter—assuming commercial supplies have leveled out by then. If Horizon is able to start its chronic TED trial then, it could still deliver data in the first quarter of 2022, the company said.

The Tepezza squeeze shouldn't throw a wrench into the company's full-year sales forecast, Horizon said. The drug is still expected to pull in more than $800 million in 2020 net sales. 

RELATED: Halozyme scores $190M Horizon deal to develop subQ Tepezza formula

As the pandemic progressed and the vaccine race heated up, Catalent became a manufacturing cornerstone in a slew of leading COVID-19 vaccine programs.

Johnson & Johnson initially tapped Catalent in April to reserve fill-finish capacity at its Bloomington, Indiana, plant—where Tepezza is made—before signing on the CDMO's Anagni, Italy facility for additional production work in July.

Plus, J&J isn't the only shot maker filling up space at Catalent's Bloomington plant: Moderna, for its part, enlisted Catalent in June to carry out fill-finish work on 100 million doses of its mRNA vaccine at Catalent's Indiana site. Moderna has since signed up to provide 100 million more doses of its shot to the U.S. in the first half of next year.

Meanwhile, Catalent in June struck a deal with AstraZeneca to perform fill-finish duties for hundreds of millions of doses at its site in Anagni, Italy. The partners added to their deal in August, roping in Catalent's Harmans, Maryland, gene therapy facility to crank out drug substance, including viral vectors, for AZ's vaccine. 

Editor's note: This story was updated with comments from Catalent.