Amgen makes progress with its Horizon prize Tepezza, but there's much work left to do

After Amgen completed its $27.8 billion buyout of Horizon Therapeutics in October, executives at the California biotech made it a priority to right the course of thyroid eye disease treatment Tepezza—an instant blockbuster which saw a perplexing slide in just its third full year on the market.

Fourth-quarter sales of Tepezza show that Amgen is making progress but the company has lots of work ahead to get the drug back on its previous trajectory.

Sales of Tepezza came in at $467 million during the period, down from $493 million in the fourth quarter of 2022 but a 3% sequential increase. It was the third straight quarter in which sales had risen, up from $405 million in the first quarter of 2023 to $445 million in the second and $453 million in the third.

“We saw a number of positive leading indicators, including a record number of unique Tepezza prescribers, total patient enrollment forms and patient starts in 2023,” Vikram Karnani, who leads Amgen’s rare disease business, said on a conference call.

Karnani added that there is an untapped market of approximately 100,000 patients in the U.S. with moderate to severe disease who could benefit from Tepezza.

Tepezza, the lone approved treatment for the condition, garnered sales of $1.66 billion in its first full year on the market (2021) and $1.97 billion in 2022 before stalling out. More recently, Horizon had reported sales declines for the drug.

“Given positive leading indicators and high unmet need, we see a long-term growth opportunity for Tepezza in the U.S., while also recognizing there is some time lag between our execution efforts and the realization of increased patient numbers,” said Karnani, who added that it can take up to 90 days for patients to receive treatment once they have been identified.

In the longer term, Amgen also sees an international opportunity with Tepezza. The drug is under review in Japan and the company will file this year for approval in Europe. A subcutaneous version of the treatment also is in development.

Overall, Amgen reported fourth-quarter revenue of $8.2 billion, which included $954 million in sales of new products from the acquisition of Horizon, which was completed on Oct. 6. It was a 20% hike year over year. Amgen was quick to point out that excluding contributions from the Horizon acquisition, sales of existing products grew by 5% in the period.

For the year, Amgen’s revenue came in at $28.2 billion, which was up from $26.3 billion in 2022. In 2024, the company expects revenue to fall between $32.4 billion and $33.8 billion. While the projection brackets the analyst consensus of $32.5 billion, it does leave room “for potentially some upside move to the number,” Salim Syed of Mizuho Securities wrote in a note to investors.  

Some of Amgen’s largest year-over-year gainers in the quarter were leukemia therapy Blincyto, which was up 47% to $241 million; postmenopausal drug Evenity, which gained 41% to $318 million; Humira biosimilar Amjevita, which was up 34% to $160 million; and cholesterol treatment Repatha, which saw a 25% increase to $417 million.

As for the company’s familiar blockbusters, osteoporosis drug Prolia was up 12% in the quarter to $1.1 billion, another osteoporosis treatment Xgeva was up 9% to $527 million; psoriasis drug Otezla gained 2% to $629 million; and arthritis drug Enbrel was down 8% to $1 billion.