Volume Up 13%, Price Down 3%Narrow moat

Amgen (AMGN) — moat facet

Amgen grew 10% in 2025 by selling 13% more medicine at 3% lower prices, a volume business rather than a pricing one.

Amgen's growth is a volume business now. Total product sales increased 10% in 2025, driven by volume growth of 13%, partially offset by declines in net selling price of 3%1. In the first quarter of 2026 product sales grew 4% on 9% volume growth, offset by 2% lower net selling price and 2% from lower inventory levels2.

Drivers of product sales growth, 2025 (percentage points)+13Volume-3Net selling price+10Product salesAmgen Form 10-K FY2025, MD&A
Thirteen points of volume bought ten points of sales.

That is a different company from the one that built its reputation on EPOGEN and NEUPOGEN, whose sales, like Neulasta's, have since been taken by copies3. The shift shows in which products grow. The 10-K expects Repatha's net selling price to decline by approximately mid-single digits in 20264, even as its sales rose from $2,222 million in 2024 to $3,016 million in 20255.

Volume growth is not a weakness in itself. Seventeen products are annualizing at more than $1 billion, according to the second-quarter 2026 release6, and the chief executive said six key growth drivers grew 26% and generated nearly 70% of product sales7. A company whose products are prescribed more every year has a real franchise.

But volume at falling prices needs ever more patients to stand still. The 2025 arithmetic, 13 points of volume to produce 10 points of sales8, works while the drugs are young and the patient pools large. It works less well when a drug is mature and its price cut is set by Medicare.

The tell is the gap between volume and price in the annual report. A year in which price falls by more than volume rises would mean the moat is no longer carrying the business; that has not happened yet, and 2025's 13 against 39 is the reading to beat.

Moat trajectory: Holding steady

Volume growth still outruns price declines.

The number that tests this moat
Reported
Product sales growth, volume against net price
Volume +13%, net price -3% (2025); Q1 2026 volume +9%, price -2%

Whether patients or price carry growth; price falling faster than volume rises would end the model.

Source: Amgen Form 10-K, FY2025 ↗
⚠ Threats to the moat
⚠ THREAT 01
Most Favoured Nation and a Direct Price
Amgen agreed to meet the administration's most-favoured-nation requests, which puts a ceiling over the American prices that fund most of its profit.
References
  1. ReportedTotal product sales increased 10% in 2025, driven by volume growth of 13%, partially offset by declines in net selling price of 3%.
    Amgen Form 10-K for fiscal 2025 - Item 7 MD&A: product sales, sales deductions and customer concentration. — FY2025 · publ. 13 February 2026 · source ↗
  2. ReportedIn the first quarter of 2026 product sales grew 4% on 9% volume growth, offset by 2% lower net selling price and 2% from lower inventory levels.
    Amgen first-quarter 2026 results release, Form 8-K exhibit 99.1. — Q1 2026 · publ. 30 April 2026 · source ↗
  3. ReportedThat is a different company from the one that built its reputation on EPOGEN and NEUPOGEN, whose sales, like Neulasta's, have since been taken by copies.
    Amgen Form 10-K for fiscal 2025 - Item 1 patents, biosimilars and competitors. — FY2025 · publ. 13 February 2026 · source ↗
  4. ReportedThe 10-K expects Repatha's net selling price to decline by approximately mid-single digits in 2026, even as its sales rose from $2,222 million in 2024 to $3,016 million in 2025.
    Amgen Form 10-K for fiscal 2025 - Item 1 patents, biosimilars and competitors. — FY2025 · publ. 13 February 2026 · source ↗
  5. ReportedThe 10-K expects Repatha's net selling price to decline by approximately mid-single digits in 2026, even as its sales rose from $2,222 million in 2024 to $3,016 million in 2025.
    Amgen fourth-quarter and full-year 2025 results release, Form 8-K exhibit 99.1 - product sales for 2024-2025, non-GAAP EPS and 2026 guidance. — FY2025 · publ. 3 February 2026 · source ↗
  6. ReportedSeventeen products are annualizing at more than $1 billion, according to the second-quarter 2026 release, and the chief executive said six key growth drivers grew 26% and generated nearly 70% of product sales.
    Amgen second-quarter 2026 results release, Form 8-K exhibit 99.1 - product sales performance: inflammation, rare disease and established products, and sales by region. — Q2 2026 · publ. 4 August 2026 · source ↗
  7. ReportedSeventeen products are annualizing at more than $1 billion, according to the second-quarter 2026 release, and the chief executive said six key growth drivers grew 26% and generated nearly 70% of product sales.
    Amgen second-quarter 2026 results release, Form 8-K exhibit 99.1 - product sales performance: inflammation, rare disease and established products, and sales by region. — Q2 2026 · publ. 4 August 2026 · source ↗
  8. ReportedThe 2025 arithmetic, 13 points of volume to produce 10 points of sales, works while the drugs are young and the patient pools large.
    Amgen Form 10-K for fiscal 2025 - Item 7 MD&A: product sales, sales deductions and customer concentration. — FY2025 · publ. 13 February 2026 · source ↗
  9. ReportedA year in which price falls by more than volume rises would mean the moat is no longer carrying the business; that has not happened yet, and 2025's 13 against 3 is the reading to beat.
    Amgen Form 10-K for fiscal 2025 - Item 7 MD&A: product sales, sales deductions and customer concentration. — FY2025 · publ. 13 February 2026 · source ↗
Sources
Generated September 28, 2026