Amgen's newer drugs are growing faster than Prolia and Xgeva are shrinking

Prolia and Xgeva are two medicines built on the same molecule, denosumab, and in the same quarter a year earlier they brought Amgen about $1.7 billion of sales between them. Cheaper copies, known as biosimilars, have now launched around the world, and the September 2026 quarter showed what that costs: combined sales of the two fell 45% from a year earlier, a loss of $758 million. Amgen's total product sales still rose, because everything else it sells added about $1.5 billion.

The decline is getting steeper, as management said it would. The pair had fallen by about a third from a year earlier in each of the first two quarters, and at its April results the company said erosion would accelerate through the rest of the year. Lower volume accounted for just over half of Prolia's drop last quarter, and the rest was split equally between lower net prices and changes in estimated sales deductions.

What covered the gap was not one drug but a spread of them. Uplizna, for rare autoimmune diseases, and Repatha, a cholesterol-lowering injection, added the most sales from a year earlier, followed by the lung-cancer drug Imdelltra, the osteoporosis drug Evenity, the asthma drug Tezspire and the leukaemia drug Blincyto. Not all of the growth elsewhere in the portfolio came from higher volume: Enbrel's sales rose on changes in sales deductions and higher inventory while its net price fell.

That replacement is why the company's revenue guidance has moved one way all year. Amgen opened the year expecting total revenues of $37.0 billion to $38.4 billion, raised the range in April and again in August, and has now lifted it to $38.9 billion to $39.7 billion.

Reported profit makes the improvement look larger than it is. The operating margin shown in the tables below, operating income divided by total revenues, rose from 26.4% to 35.8%. About three-quarters of the rise in operating income, calculated from the company's reconciliation, came from smaller acquisition-related charges: lower amortisation of acquisition-related assets, and a $59 million impairment charge in place of the $400 million taken on Otezla a year earlier. These are non-cash charges tied to past deals. On the company's adjusted measure, which leaves them out, operating margin on product sales edged up from 47.1% to 47.3%.

The new range also says something about the last quarter of the year. With nine months of revenue reported, it leaves fourth-quarter revenue anywhere from flat to about 8% above a year earlier, calculated from the reported figures. Management expects operating expenses to rise noticeably in that quarter, its usual year-end pattern, and kept full-year adjusted operating margin guidance at roughly 45% to 46% of product sales, below the adjusted margin earned so far this year.

Thomas Dittrich, presenting his first results as chief financial officer, gave the company's first view of next year: "Looking ahead to 2027, we do not anticipate a step-down in operating margin compared with our 2026 guidance." The yardstick is the guided range rather than the higher margin Amgen has actually earned this year. Some of the cost of the newer growth already shows: on the adjusted measure, cost of sales rose as a share of product sales last quarter, which the company put down to higher profit-share expense and a changing sales mix.