Other PharmaceuticalNarrow moat

Merck & Co. (MRK) — moat facet

Merck's other human medicines sell $21 billion a year, and each launch is racing an exclusivity loss elsewhere in the portfolio.

1. Moat Explorer calcAfter Keytruda and Gardasil, Merck's human medicines and vaccines sold $21,228 million in 2025, about 32.7% of total sales.
   Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - revenue mix, concentration and geography. — 2015-2026 · publ. September 2026 · source ↗
   Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
2. Moat Explorer calcAfter Keytruda and Gardasil, Merck's human medicines and vaccines sold $21,228 million in 2025, about 32.7% of total sales.
   Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - revenue mix, concentration and geography. — 2015-2026 · publ. September 2026 · source ↗
   Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
3. Moat Explorer calcIn the second quarter of 2026 this portion sold about $5,225 million, up about 5.2%.
   Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - growth rates and changes. — 2015-2026 · publ. September 2026 · source ↗
   Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
4. ReportedGrowing: Winrevair $1,443 million, Welireg $716 million, Prevymis $978 million, Capvaxive $759 million and Vaxneuvance $825 million in 2025.
   Merck & Co. Form 10-K for fiscal 2025 - vaccines and China: Gardasil, the childhood and pneumococcal vaccines, and sales in China. — FY2025 · publ. 24 February 2026 · source ↗
5. ReportedSteady: Bridion $1,841 million, the childhood vaccines $2,451 million, RotaTeq $673 million.
   Merck & Co. Form 10-K for fiscal 2025 - vaccines and China: Gardasil, the childhood and pneumococcal vaccines, and sales in China. — FY2025 · publ. 24 February 2026 · source ↗
6. ReportedFading: Januvia $1,604 million and Janumet $940 million, Lagevrio $380 million, Pneumovax 23 $166 million.
   Merck & Co. Form 10-K for fiscal 2025 - vaccines and China: Gardasil, the childhood and pneumococcal vaccines, and sales in China. — FY2025 · publ. 24 February 2026 · source ↗
7. ReportedAlliance revenue from Lynparza, $1,450 million, and Lenvima, $1,053 million, and royalties on Reblozyl, $525 million, are also here.
   Merck & Co. Form 10-K for fiscal 2025 - patents, exclusivity dates, biosimilar competition and royalties. — FY2025 · publ. 24 February 2026 · source ↗
8. ReportedThis portion was $19,895 million in 2021, rose to $24,171 million in 2022 on the COVID antiviral Lagevrio, which sold $5,684 million that year, and fell to $19,686 million in 2023.
   Merck & Co. Form 10-K for fiscal 2023 - product sales for 2021-2023, the Prometheus, Daiichi Sankyo and Imago charges, impairments, receivables concentration and the Zhifei distribution arrangement in China. — FY2023 · publ. February 2024 · source ↗
9. Moat Explorer calcThis portion was $19,895 million in 2021, rose to $24,171 million in 2022 on the COVID antiviral Lagevrio, which sold $5,684 million that year, and fell to $19,686 million in 2023.
   Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - growth rates and changes. — 2015-2026 · publ. September 2026 · source ↗
   Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
10. ReportedSimponi and Remicade, which sold $710 million and $187 million in 2023, went back to Johnson & Johnson when their marketing rights in former Merck territories returned on 1 October 2024.
    Merck & Co. Form 10-K for fiscal 2025 - financial statements and notes: earnings, cash flow, balance sheet, acquisitions, research and segment profit. — FY2025 · publ. 24 February 2026 · source ↗
11. ReportedSimponi and Remicade, which sold $710 million and $187 million in 2023, went back to Johnson & Johnson when their marketing rights in former Merck territories returned on 1 October 2024.
    Merck & Co. Form 10-K for fiscal 2025 - financial statements and notes: earnings, cash flow, balance sheet, acquisitions, research and segment profit. — FY2025 · publ. 24 February 2026 · source ↗
12. ReportedHow it is paid varies by product, but the channels are the same wholesalers, hospitals, government agencies and benefit managers as for Keytruda; alliance products book only Merck's share of profits.
    Merck & Co. Form 10-K for fiscal 2025 - Item 1 business: products, customers, segments and people. — FY2025 · publ. 24 February 2026 · source ↗
13. ReportedHow it is paid varies by product, but the channels are the same wholesalers, hospitals, government agencies and benefit managers as for Keytruda; alliance products book only Merck's share of profits.
    Merck & Co. Form 10-K for fiscal 2025 - Item 1 business: products, customers, segments and people. — FY2025 · publ. 24 February 2026 · source ↗
14. Moat Explorer calcProfitability is not disclosed by product; the segment margin was about 78.7% in 2025.
    Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - product and segment totals, growth and royalties. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
15. ReportedSeveral products are not wholly Merck's: it pays a 22% royalty on Winrevair to Bristol Myers Squibb.
    Merck & Co. Form 10-K for fiscal 2025 - patents, exclusivity dates, biosimilar competition and royalties. — FY2025 · publ. 24 February 2026 · source ↗
16. ReportedJanuvia and Janumet lost American exclusivity in 2026 and fell 31% in the second quarter; Bridion lost it in July 2026; Lynparza and Bravecto follow in 2027.
    Merck & Co. Form 10-Q for the quarter ended 30 June 2026 - segment profits on the recast basis, the Cidara and Terns acquisitions, the Halozyme litigation, China shipments, loss of exclusivity events and the balance sheet. — Q2 2026 · publ. 7 August 2026 · source ↗
17. ReportedJanuvia and Janumet lost American exclusivity in 2026 and fell 31% in the second quarter; Bridion lost it in July 2026; Lynparza and Bravecto follow in 2027.
    Merck second-quarter 2026 results release, Form 8-K exhibit 99.1 - vaccine and Animal Health sales. — Q2 2026 · publ. 4 August 2026 · source ↗
18. ReportedJanuvia and Janumet lost American exclusivity in 2026 and fell 31% in the second quarter; Bridion lost it in July 2026; Lynparza and Bravecto follow in 2027.
    Merck & Co. Form 10-Q for the quarter ended 30 June 2026 - segment profits on the recast basis, the Cidara and Terns acquisitions, the Halozyme litigation, China shipments, loss of exclusivity events and the balance sheet. — Q2 2026 · publ. 7 August 2026 · source ↗
19. ReportedJanuvia and Janumet lost American exclusivity in 2026 and fell 31% in the second quarter; Bridion lost it in July 2026; Lynparza and Bravecto follow in 2027.
    Merck & Co. Form 10-K for fiscal 2025 - patents, exclusivity dates, biosimilar competition and royalties. — FY2025 · publ. 24 February 2026 · source ↗
20. ReportedLagevrio, the COVID antiviral, sold $952 million in 2021, $5,684 million in 2022 and $380 million in 2025, so the line's 2022 peak was a pandemic rather than a franchise.
    Merck & Co. Form 10-K for fiscal 2023 - product sales for 2021-2023, the Prometheus, Daiichi Sankyo and Imago charges, impairments, receivables concentration and the Zhifei distribution arrangement in China. — FY2023 · publ. February 2024 · source ↗
21. ReportedLagevrio, the COVID antiviral, sold $952 million in 2021, $5,684 million in 2022 and $380 million in 2025, so the line's 2022 peak was a pandemic rather than a franchise.
    Merck & Co. Form 10-K for fiscal 2025 - Item 7 MD&A and product sales note: sales by product, segment and country. — FY2025 · publ. 24 February 2026 · source ↗
22. ReportedWelireg, a kidney cancer drug, went from $13 million in 2021 to $716 million in 2025, and grew 67% to $271 million in the second quarter of 2026: the kind of product that must multiply for this line to matter after 2028.
    Merck & Co. Form 10-K for fiscal 2023 - product sales for 2021-2023, the Prometheus, Daiichi Sankyo and Imago charges, impairments, receivables concentration and the Zhifei distribution arrangement in China. — FY2023 · publ. February 2024 · source ↗
23. ReportedWelireg, a kidney cancer drug, went from $13 million in 2021 to $716 million in 2025, and grew 67% to $271 million in the second quarter of 2026: the kind of product that must multiply for this line to matter after 2028.
    Merck & Co. Form 10-K for fiscal 2025 - Item 1 business: products, customers, segments and people. — FY2025 · publ. 24 February 2026 · source ↗
24. ReportedWelireg, a kidney cancer drug, went from $13 million in 2021 to $716 million in 2025, and grew 67% to $271 million in the second quarter of 2026: the kind of product that must multiply for this line to matter after 2028.
    Merck second-quarter 2026 results release, Form 8-K exhibit 99.1 - sales by product and pipeline highlights. — Q2 2026 · publ. 4 August 2026 · source ↗
25. ReportedMerck books only its share of profits on Lynparza with AstraZeneca and Lenvima with Eisai, which makes their reported figures smaller and more profitable than an owned product of the same size.
    Merck & Co. Form 10-K for fiscal 2025 - Item 1 business: products, customers, segments and people. — FY2025 · publ. 24 February 2026 · source ↗
26. ReportedLenvima has been selected for a Medicare price effective in 2028, and Lynparza's American protection ends in 2027, so two of the line's larger pieces face their own dates before Keytruda's.
    Merck & Co. Form 10-K for fiscal 2025 - Item 1A risk factors, patents and exclusivity, government pricing, vaccine policy and legal proceedings. — FY2025 · publ. 24 February 2026 · source ↗
27. ReportedLenvima has been selected for a Medicare price effective in 2028, and Lynparza's American protection ends in 2027, so two of the line's larger pieces face their own dates before Keytruda's.
    Merck & Co. Form 10-K for fiscal 2025 - Item 1A risk factors, patents and exclusivity, government pricing, vaccine policy and legal proceedings. — FY2025 · publ. 24 February 2026 · source ↗
28. Moat Explorer calcThe quarterly sales of this portion, about $5.2 billion in the second quarter of 2026, are the figure to hold it to; growth that turns negative in 2027 as Bridion and the diabetes drugs fade would mean the launches are not yet large enough to carry the portfolio, let alone Keytruda.
    Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - growth rates and changes. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.

• Merck Form 10-K, FY2025