Amgen's new Horizon products bolster top line despite continued Tepezza struggles

During the Q&A portion of Amgen’s quarterly conference call Thursday, eight of the first nine questions were about the company’s investigational efforts in obesity.

The buzz about Amgen’s pipeline—and specifically about its promising weight loss therapy MariTide—overshadowed the company’s solid work on the top line, where revenue came in at $7.4 billion. It was a 22% increase on the $6.1 billion in sales the company achieved in the first quarter of last year.

Much of the boost can be attributed to sales of products acquired in Amgen’s $27.8 billion buyout of Horizon Therapeutics, which was completed early in the fourth quarter of last year. Assets brought by Horizon accounted for sales of $914 million, a 10% increase on the $832 million the rare disease specialist generated in the first quarter of last year.  

The big gainers from Horizon were gout treatment Krystexxa, which was up 26% to $235 million, and neuromyelitis optica spectrum disorder drug Uplizna, which saw an increase of 48% year over year to $80 million.

Thyroid eye disease (TED) drug Tepezza was the top-selling Horizon import, generating $424 million in the quarter. While that represented a 5% increase year over year, sales were down sequentially, dropping from $467 million in the fourth quarter of 2023.

Tepezza has been on a curious roller coaster ride, raking in sales of $1.7 billion in 2021 in its first full year on the market, followed by $2 billion in 2022. Since then, however, Tepezza’s momentum has stalled, despite it being the world’s lone treatment for TED.

A phase 3 trial is underway, testing a more user-friendly subcutaneous version of Tepezza that the company believes will help it regain its traction. Amgen also has submitted for approval of the treatment in Europe.

"Tepezza came in slightly below consensus estimates, although in line with management guidance and our estimates," William Blair analyst Matt Phipps, Ph.D., wrote in a note to clients. "We continue to have reservations on the near-term growth of Tepezza prior to geographic expansion."

Without breaking them out individually, Amgen said that five other ultra-rare disease drugs from Horizon combined to generate $169 million in sales. In the first quarter of 2023, these treatments—Procysbi (nephropathic cystinosis), Quinsair (lung infection), Actimmune (chronic granulomatous disease) and Ravicti and Burhenyl (both for urea cycle disorder)—combined for revenue of $172 million.

As for Amgen’s stalwarts, osteoporosis treatment Prolia had an 8% increase year over year to $1 billion. Meanwhile, rheumatoid arthritis drug Enbrel—which is one of 10 products identified for Medicare negotiations under the Inflation Reduction Act—saw sales drop 2% compared to a year ago, to $567 million.

That decline was even starker on a sequential basis, plummeting from sales of $1 billion in the previous quarter. The company said the drop happens annually because of the impact of benefit plan changes, insurance reverifications and increased co-pay expenses as U.S. patients work through deductibles.

Amgen’s big gainers were asthma drug Tezspire, which was up 80% to $173 million; osteoporosis therapy Evenity, which grew $35% to $342 million; cholesterol treatment Repatha, which increased sales 33% to $517 million; and leukemia drug Blincyto, which was up 26% to $244 million.

Amgen CEO Robert Bradway cited the four products in affirming his confidence in the company’s ability to grow over the next several years, adding that Blincyto is on the verge of approval into an earlier treatment line and that the company will share data later this month that demonstrate Tezspire’s potential to treat chronic obstructive pulmonary disease.