TEPEZZA and KRYSTEXXA: No Direct CompetitorWide moat

Amgen (AMGN) — moat facet

TEPEZZA and KRYSTEXXA sold $3.2 billion in 2025 with no direct competitor in America, Europe or Japan, which is why Amgen paid for Horizon.

TEPEZZA and KRYSTEXXA are the heart of the Horizon purchase, and their value lies in one sentence of Amgen's 10-K: they currently do not face any direct competitors in the United States, Europe or Japan1. For a company whose other drugs pay ever larger rebates, that is the scarce asset.

Rare-disease sales without a direct competitor, 2025 ($M)TEPEZZA1,903KRYSTEXXA1,340Amgen FY2025 results release; competitive position per Form 10-K FY2025
$3.2 billion with no direct rival.

TEPEZZA treats thyroid eye disease, a condition that can push the eyes forward and cause double vision. It sold $448 million in the months after the acquisition in 2023, $1,851 million in 2024 and $1,903 million in 202523, and $576 million in the second quarter of 20264. KRYSTEXXA treats chronic gout that has not responded to other drugs; it sold $1,185 million in 2024 and $1,340 million in 20255, and $400 million in the second quarter of 20266.

Here, unusually for Amgen, price rises. In the second quarter of 2026 KRYSTEXXA's sales grew 15%, driven by 23% higher net selling price, and TEPEZZA's 14%, on 6% higher net selling price and 6% volume growth7. The 10-K calls KRYSTEXXA the first and only FDA-approved medicine for the treatment of chronic refractory gout8. For the full year 2025, KRYSTEXXA grew about 13% and TEPEZZA about 3%9. TEPEZZA's growth now depends on reaching patients outside the United States, and its protection is long: antibody patents to March 2029, treatment patents to December 2039, and American biologic exclusivity to 203210.

A drug with no direct competitor still has competitors in the broader sense: surgery and steroids for thyroid eye disease, cheaper gout drugs for patients who respond to them. Its pricing power depends on doctors deciding that a patient needs it.

The combination sold $3,243 million in 202511. If their combined growth falls below 5% a year while Amgen reports no new competitor, the absence of rivals will have turned out to mean a small market rather than a strong franchise.

Moat trajectory: Holding steady

KRYSTEXXA growing double digits; TEPEZZA growing slowly.

The number that tests this moat
Reported
TEPEZZA and KRYSTEXXA sales, latest quarter
$976M (Q2 2026: 576 and 400)

The core of the Horizon price; growth below 5% a year would mean no rivals but no growth either.

Source: Amgen Q2 2026 results release ↗
⚠ Threats to the moat
⚠ THREAT 01
KRYSTEXXA Molecule Patent Ended in April 2026
The patent on KRYSTEXXA's molecule ended in April 2026, leaving a treatment patent to 2040 as the main defence.
References
  1. ReportedTEPEZZA and KRYSTEXXA are the heart of the Horizon purchase, and their value lies in one sentence of Amgen's 10-K: they currently do not face any direct competitors in the United States, Europe or Japan.
    Amgen Form 10-K for fiscal 2025 - Item 1 patents, biosimilars and competitors. — FY2025 · publ. 13 February 2026 · source ↗
  2. ReportedIt sold $448 million in the months after the acquisition in 2023, $1,851 million in 2024 and $1,903 million in 2025, and $576 million in the second quarter of 2026.
    Amgen fourth-quarter and full-year 2023 results release, Form 8-K exhibit 99.1 - product sales for 2022-2023. — FY2023 · publ. February 2024 · source ↗
  3. ReportedIt sold $448 million in the months after the acquisition in 2023, $1,851 million in 2024 and $1,903 million in 2025, and $576 million in the second quarter of 2026.
    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 ↗
  4. ReportedIt sold $448 million in the months after the acquisition in 2023, $1,851 million in 2024 and $1,903 million in 2025, and $576 million in the second quarter of 2026.
    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 ↗
  5. ReportedKRYSTEXXA treats chronic gout that has not responded to other drugs; it sold $1,185 million in 2024 and $1,340 million in 2025, and $400 million in the second quarter of 2026.
    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. ReportedKRYSTEXXA treats chronic gout that has not responded to other drugs; it sold $1,185 million in 2024 and $1,340 million in 2025, and $400 million in the second quarter of 2026.
    Amgen second-quarter 2026 results release, Form 8-K exhibit 99.1 - product sales performance: inflammation, rare disease and established products, and sales by region. — Q2 2026 · publ. 4 August 2026 · source ↗
  7. ReportedIn the second quarter of 2026 KRYSTEXXA's sales grew 15%, driven by 23% higher net selling price, and TEPEZZA's 14%, on 6% higher net selling price and 6% volume growth.
    Amgen second-quarter 2026 results release, Form 8-K exhibit 99.1 - product sales performance: inflammation, rare disease and established products, and sales by region. — Q2 2026 · publ. 4 August 2026 · source ↗
  8. ReportedThe 10-K calls KRYSTEXXA the first and only FDA-approved medicine for the treatment of chronic refractory gout.
    Amgen Form 10-K for fiscal 2025 - Item 1 business: products, collaborations, staff and pipeline. — FY2025 · publ. 13 February 2026 · source ↗
  9. Moat Explorer calcFor the full year 2025, KRYSTEXXA grew about 13% and TEPEZZA about 3%.
    Moat Explorer calculation from Amgen's reported product sales and financial statements ($ millions unless stated). Sales deductions: 2019 rebates 6,825 + chargebacks 7,090 + other 1,292 = 15,207; 2025 21,697 + 16,988 + 3,298 = 41,983; 41,983 / 35,148 = 1.19 times net product sales; implied gross product sales 35,148 + 41,983 = 77,131. Growth 2019-2025: deductions 41,983 / 15,207 = 2.76 times; net product sales 35,148 / 22,204 = 1.58 times (up 58%); rebates 21,697 / 6,825 = 3.18 times; chargebacks 16,988 / 7,090 = 2.4 times. Wholesalers 2025 gross: 26,253 + 20,986 + 12,562 = 59,801; 59,801 / 36,751 = 1.63 times total revenues; McKesson 26,253 / 36,751 = 71%. ENBREL: 2,226 / 5,433 - 1 = -59%; share of product sales 5,226 / 22,204 = 23.5% (2019), 2,226 / 35,148 = 6.3% (2025). ENBREL + Otezla 2025: 2,226 + 2,265 = 4,491; 4,491 / 36,751 = 12%. Otezla sales 2020-2025: 2,195 + 2,249 + 2,288 + 2,188 + 2,126 + 2,265 = 13,311; impairment 1,200 / 13,400 = 9%. Horizon products: 2023 448 + 272 + 65 + 164 = 949; 2024 1,851 + 1,185 + 379 + 758 = 4,173; 2025 1,903 + 1,340 + 655 + 719 = 4,617, 4,617 / 27,800 = 16.6%; Q2 2026 576 + 400 + 335 + 149 = 1,460, x4 = 5,840. TEPEZZA + KRYSTEXXA 2025 1,903 + 1,340 = 3,243; KRYSTEXXA 1,340 / 1,185 - 1 = 13.1%; TEPEZZA 1,903 / 1,851 - 1 = 2.8%; UPLIZNA 655 / 379 - 1 = 72.8%; H1 2026 262 + 335 = 597; ultra-rare 719 / 758 - 1 = -5.1%; UPLIZNA + ultra-rare 655 + 719 = 1,374. TAVNEOS H1 2026 119 + 150 = 269. Acquisitions: 13.4 + 3.9 + 27.8 = 45.1 bn; acquired products 2025 2,265 + 459 + 4,617 = 7,341, 7,341 / 36,751 = 20%. Interest 2,755 / 9,080 = 30%. Net debt 30 June 2026: 57.3 - 13.989 = 43.3 bn. Goodwill + intangibles 18,680 + 22,276 = 40,956, 40,956 / 90,586 = 45%. EPS gap 21.84 - 14.23 = 7.61. R&D 7,272 / 4,784 - 1 = 52%; 7,272 / 36,751 = 19.8%. Growth drivers 2025: Repatha 3,016 + EVENITY 2,100 + TEZSPIRE 1,478 + BLINCYTO 1,559 = 8,153 (2024: 2,222 + 1,563 + 972 + 1,216 = 5,973; 2023: 1,635 + 1,160 + 567 + 861 = 4,223; 2021: 1,117 + 530 + 0 + 472 = 2,119; 2019: 661 + 189 + 0 + 312 = 1,162); 8,153 / 5,973 - 1 = 36.5%, about 37%; 8,153 / 36,751 = 22%. Repatha 3,016 / 661 = 4.6 times, 3,016 / 2,222 - 1 = 36%; EVENITY 2,100 / 189 = 11 times; BLINCYTO 1,559 / 312 = 5.0 times. KYPROLIS 1,412 / 1,503 - 1 = -6%; KYPROLIS + Nplate 1,412 + 1,524 = 2,936, 2,936 / 6,660 = 44%; BLINCYTO + IMDELLTRA 1,559 + 627 = 2,186; Q2 2026 472 + 288 = 760. IMDELLTRA run rate 288 x 4 = 1,152, 1,152 / 6,498 = 18%. Biosimilars: 2025 AMJEVITA 597 + PAVBLU 700 + WEZLANA 273 + MVASI 771 + in other products 683 = 3,024; 3,024 / 35,148 = 8.6% of product sales; 3,024 / 36,751 = 8.2% of total revenues; PAVBLU 700 / 3,024 = 23%; AMJEVITA 597 / 761 - 1 = -22%; band 2022 1,831 / 2,177 - 1 = -16%; in other products 683 / 667 - 1 = 2%; WEZLANA and other biosimilars added (273 - 27) + (683 - 667) = 262; Q2 2026 155 + 287 + 61 + 153 + 199 = 855; Q2 2025 133 + 130 + 35 + 191 + 172 = 661; 855 / 661 - 1 = 29%; shares of total revenues 568 / 23,362 = 2.4% (2019), 2,177 / 25,979 = 8.4% (2021), 1,916 / 28,190 = 6.8% (2023). Bands 2025: general medicine and bone 3,016 + 2,100 + 4,414 + 2,084 = 11,614 (31.6%); inflammation and rare disease 2,226 + 2,265 + 1,478 + 1,903 + 1,340 + 655 + 459 + 719 = 11,045 (30.1%); oncology 1,559 + 627 + 1,175 + 1,412 + 363 + 1,524 = 6,660 (18.1%); biosimilars 3,024 (8.2%); established and other 1,389 + 435 + 353 + (1,311 - 683 = 628) + 1,603 = 4,408 (12.0%); total 36,751. 2019 bands 5,457; 5,404; 2,895; 568; 9,038; total 23,362. General medicine 11,614 / 5,457 = 2.1 times, 11,614 / 10,384 - 1 = 11.8%; inflammation 2020 7,191, 2024 10,870 / 7,535 - 1 = 44%, 2025 11,045 / 10,870 - 1 = 1.6%, non-ENBREL-Otezla 11,045 - 4,491 = 6,554; oncology 6,660 / 2,895 = 2.3 times, 6,660 / 5,685 - 1 = 17.2%; established 4,408 / 9,038 = 0.49. Q2 bands 2026 vs 2025: general medicine 953 + 714 + 759 + 352 = 2,778 vs 696 + 518 + 1,122 + 532 = 2,868, down 3%; Repatha + EVENITY 1,667 vs 1,214; denosumab 1,111 vs 1,654, down 33%; inflammation 3,167 vs 604 + 618 + 342 + 505 + 349 + 176 + 110 + 183 = 2,887, up 9.7%; oncology 1,953 vs 384 + 134 + 305 + 378 + 90 + 369 = 1,660, up 17.7%; established and other 632 + (351 - 199) + 517 = 1,301 vs 359 + 82 + 92 + (334 - 172) + 408 = 1,103, up 18%. Denosumab 2025 4,414 + 2,084 = 6,498, 6,498 / 36,751 = 17.7%; Q1 2026 727 + 411 = 1,138; H1 2026 1,486 + 763 = 2,249 vs 2,221 + 1,098 = 3,319. Neulasta 435 / 4,534 - 1 = -90%. Geography: US 25,656 / 35,148 = 73%; rest of world 9,492 / 35,148 = 27.0%; Q2 2026 2,547 / 9,537 = 26.7%; AMJEVITA 129 / 155 = 83.2%; Aranesp 258 / 352 = 73.3%; ENBREL 6 / 580 = 1.0%. Novartis-facing 2025 3,016 + 2,265 + 2,226 + 1,524 + 1,478 = 10,509, 10,509 / 36,751 = 29%. Other revenues 1,603 / 36,751 = 4.4%. Receivables 9,570 / 6,782 - 1 = 41%. Guidance midpoints: (37.0 + 38.4) / 2 = 37.7; (37.1 + 38.5) / 2 = 37.8; (38.2 + 39.4) / 2 = 38.8; non-GAAP EPS (22.30 + 23.50) / 2 = 22.90. IRS: 3.6 + 5.1 + 2.0 = 10.7 bn before interest; offsets 0.9 + 2.2 = 3.1 bn; 10.7 / 7.711 = 1.4 times 2025 net income; 10.7 / 224.15 = 4.8% of market value. Trailing free cash flow 8,100 - 2,891 + 4,966 = 10,175; 10,175 / 224,150 = 4.5%. Shares 538.8 / 629.6 - 1 = -14%. Gross margin (total revenues - cost of sales) / total revenues: (28,190 - 8,451) / 28,190 = 70.0% (2023); (33,424 - 12,858) / 33,424 = 61.5% (2024); (36,751 - 12,037) / 36,751 = 67.2% (2025). Pre-tax income 2025 7,711 + 1,265 = 8,976. Total revenues 36,751 / 21,662 = 1.70 times 2015. Market value 224.15 / 176.25 - 1 = 27% in 2026; added 224.15 - 176.25 = 47.9 bn against 176.25 - 122.45 = 53.8 bn in 2015-2025. Trailing net income 7,711 - 3,162 + 4,194 = 8,743; trailing revenue 36,751 - 17,328 + 18,672 = 38,095 - product and band totals, growth and sales deductions. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in Amgen's Forms 10-K, 10-Q, results releases and market data; operands shown in the source line.
  10. ReportedTEPEZZA's growth now depends on reaching patients outside the United States, and its protection is long: antibody patents to March 2029, treatment patents to December 2039, and American biologic exclusivity to 2032.
    Amgen Form 10-K for fiscal 2025 - Item 1 patents, biosimilars and competitors. — FY2025 · publ. 13 February 2026 · source ↗
  11. Moat Explorer calcThe combination sold $3,243 million in 2025.
    Moat Explorer calculation from Amgen's reported product sales and financial statements ($ millions unless stated). Sales deductions: 2019 rebates 6,825 + chargebacks 7,090 + other 1,292 = 15,207; 2025 21,697 + 16,988 + 3,298 = 41,983; 41,983 / 35,148 = 1.19 times net product sales; implied gross product sales 35,148 + 41,983 = 77,131. Growth 2019-2025: deductions 41,983 / 15,207 = 2.76 times; net product sales 35,148 / 22,204 = 1.58 times (up 58%); rebates 21,697 / 6,825 = 3.18 times; chargebacks 16,988 / 7,090 = 2.4 times. Wholesalers 2025 gross: 26,253 + 20,986 + 12,562 = 59,801; 59,801 / 36,751 = 1.63 times total revenues; McKesson 26,253 / 36,751 = 71%. ENBREL: 2,226 / 5,433 - 1 = -59%; share of product sales 5,226 / 22,204 = 23.5% (2019), 2,226 / 35,148 = 6.3% (2025). ENBREL + Otezla 2025: 2,226 + 2,265 = 4,491; 4,491 / 36,751 = 12%. Otezla sales 2020-2025: 2,195 + 2,249 + 2,288 + 2,188 + 2,126 + 2,265 = 13,311; impairment 1,200 / 13,400 = 9%. Horizon products: 2023 448 + 272 + 65 + 164 = 949; 2024 1,851 + 1,185 + 379 + 758 = 4,173; 2025 1,903 + 1,340 + 655 + 719 = 4,617, 4,617 / 27,800 = 16.6%; Q2 2026 576 + 400 + 335 + 149 = 1,460, x4 = 5,840. TEPEZZA + KRYSTEXXA 2025 1,903 + 1,340 = 3,243; KRYSTEXXA 1,340 / 1,185 - 1 = 13.1%; TEPEZZA 1,903 / 1,851 - 1 = 2.8%; UPLIZNA 655 / 379 - 1 = 72.8%; H1 2026 262 + 335 = 597; ultra-rare 719 / 758 - 1 = -5.1%; UPLIZNA + ultra-rare 655 + 719 = 1,374. TAVNEOS H1 2026 119 + 150 = 269. Acquisitions: 13.4 + 3.9 + 27.8 = 45.1 bn; acquired products 2025 2,265 + 459 + 4,617 = 7,341, 7,341 / 36,751 = 20%. Interest 2,755 / 9,080 = 30%. Net debt 30 June 2026: 57.3 - 13.989 = 43.3 bn. Goodwill + intangibles 18,680 + 22,276 = 40,956, 40,956 / 90,586 = 45%. EPS gap 21.84 - 14.23 = 7.61. R&D 7,272 / 4,784 - 1 = 52%; 7,272 / 36,751 = 19.8%. Growth drivers 2025: Repatha 3,016 + EVENITY 2,100 + TEZSPIRE 1,478 + BLINCYTO 1,559 = 8,153 (2024: 2,222 + 1,563 + 972 + 1,216 = 5,973; 2023: 1,635 + 1,160 + 567 + 861 = 4,223; 2021: 1,117 + 530 + 0 + 472 = 2,119; 2019: 661 + 189 + 0 + 312 = 1,162); 8,153 / 5,973 - 1 = 36.5%, about 37%; 8,153 / 36,751 = 22%. Repatha 3,016 / 661 = 4.6 times, 3,016 / 2,222 - 1 = 36%; EVENITY 2,100 / 189 = 11 times; BLINCYTO 1,559 / 312 = 5.0 times. KYPROLIS 1,412 / 1,503 - 1 = -6%; KYPROLIS + Nplate 1,412 + 1,524 = 2,936, 2,936 / 6,660 = 44%; BLINCYTO + IMDELLTRA 1,559 + 627 = 2,186; Q2 2026 472 + 288 = 760. IMDELLTRA run rate 288 x 4 = 1,152, 1,152 / 6,498 = 18%. Biosimilars: 2025 AMJEVITA 597 + PAVBLU 700 + WEZLANA 273 + MVASI 771 + in other products 683 = 3,024; 3,024 / 35,148 = 8.6% of product sales; 3,024 / 36,751 = 8.2% of total revenues; PAVBLU 700 / 3,024 = 23%; AMJEVITA 597 / 761 - 1 = -22%; band 2022 1,831 / 2,177 - 1 = -16%; in other products 683 / 667 - 1 = 2%; WEZLANA and other biosimilars added (273 - 27) + (683 - 667) = 262; Q2 2026 155 + 287 + 61 + 153 + 199 = 855; Q2 2025 133 + 130 + 35 + 191 + 172 = 661; 855 / 661 - 1 = 29%; shares of total revenues 568 / 23,362 = 2.4% (2019), 2,177 / 25,979 = 8.4% (2021), 1,916 / 28,190 = 6.8% (2023). Bands 2025: general medicine and bone 3,016 + 2,100 + 4,414 + 2,084 = 11,614 (31.6%); inflammation and rare disease 2,226 + 2,265 + 1,478 + 1,903 + 1,340 + 655 + 459 + 719 = 11,045 (30.1%); oncology 1,559 + 627 + 1,175 + 1,412 + 363 + 1,524 = 6,660 (18.1%); biosimilars 3,024 (8.2%); established and other 1,389 + 435 + 353 + (1,311 - 683 = 628) + 1,603 = 4,408 (12.0%); total 36,751. 2019 bands 5,457; 5,404; 2,895; 568; 9,038; total 23,362. General medicine 11,614 / 5,457 = 2.1 times, 11,614 / 10,384 - 1 = 11.8%; inflammation 2020 7,191, 2024 10,870 / 7,535 - 1 = 44%, 2025 11,045 / 10,870 - 1 = 1.6%, non-ENBREL-Otezla 11,045 - 4,491 = 6,554; oncology 6,660 / 2,895 = 2.3 times, 6,660 / 5,685 - 1 = 17.2%; established 4,408 / 9,038 = 0.49. Q2 bands 2026 vs 2025: general medicine 953 + 714 + 759 + 352 = 2,778 vs 696 + 518 + 1,122 + 532 = 2,868, down 3%; Repatha + EVENITY 1,667 vs 1,214; denosumab 1,111 vs 1,654, down 33%; inflammation 3,167 vs 604 + 618 + 342 + 505 + 349 + 176 + 110 + 183 = 2,887, up 9.7%; oncology 1,953 vs 384 + 134 + 305 + 378 + 90 + 369 = 1,660, up 17.7%; established and other 632 + (351 - 199) + 517 = 1,301 vs 359 + 82 + 92 + (334 - 172) + 408 = 1,103, up 18%. Denosumab 2025 4,414 + 2,084 = 6,498, 6,498 / 36,751 = 17.7%; Q1 2026 727 + 411 = 1,138; H1 2026 1,486 + 763 = 2,249 vs 2,221 + 1,098 = 3,319. Neulasta 435 / 4,534 - 1 = -90%. Geography: US 25,656 / 35,148 = 73%; rest of world 9,492 / 35,148 = 27.0%; Q2 2026 2,547 / 9,537 = 26.7%; AMJEVITA 129 / 155 = 83.2%; Aranesp 258 / 352 = 73.3%; ENBREL 6 / 580 = 1.0%. Novartis-facing 2025 3,016 + 2,265 + 2,226 + 1,524 + 1,478 = 10,509, 10,509 / 36,751 = 29%. Other revenues 1,603 / 36,751 = 4.4%. Receivables 9,570 / 6,782 - 1 = 41%. Guidance midpoints: (37.0 + 38.4) / 2 = 37.7; (37.1 + 38.5) / 2 = 37.8; (38.2 + 39.4) / 2 = 38.8; non-GAAP EPS (22.30 + 23.50) / 2 = 22.90. IRS: 3.6 + 5.1 + 2.0 = 10.7 bn before interest; offsets 0.9 + 2.2 = 3.1 bn; 10.7 / 7.711 = 1.4 times 2025 net income; 10.7 / 224.15 = 4.8% of market value. Trailing free cash flow 8,100 - 2,891 + 4,966 = 10,175; 10,175 / 224,150 = 4.5%. Shares 538.8 / 629.6 - 1 = -14%. Gross margin (total revenues - cost of sales) / total revenues: (28,190 - 8,451) / 28,190 = 70.0% (2023); (33,424 - 12,858) / 33,424 = 61.5% (2024); (36,751 - 12,037) / 36,751 = 67.2% (2025). Pre-tax income 2025 7,711 + 1,265 = 8,976. Total revenues 36,751 / 21,662 = 1.70 times 2015. Market value 224.15 / 176.25 - 1 = 27% in 2026; added 224.15 - 176.25 = 47.9 bn against 176.25 - 122.45 = 53.8 bn in 2015-2025. Trailing net income 7,711 - 3,162 + 4,194 = 8,743; trailing revenue 36,751 - 17,328 + 18,672 = 38,095 - product and band totals, growth and sales deductions. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in Amgen's Forms 10-K, 10-Q, results releases and market data; operands shown in the source line.
Sources
Generated September 28, 2026