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— CH. 1 · THE MOLECULAR GENESIS —

Amgen

~5 min read · Ch. 1 of 5
5 sections
  • In April 1980, a small group of venture capitalists gathered in Thousand Oaks to establish Applied Molecular Genetics. This entity would soon change its name to Amgen and become a titan of the biopharmaceutical industry. The founders focused their early efforts on recombinant DNA technology and human insulin production. By October 1980, they appointed George Rathmann as their first president and chief executive officer. A scientific advisory board formed around key figures like Norman Davidson and Leroy Hood. These experts guided the company through its initial years of research and development.

    On the 17th of June 1983, the company went public via an initial public offering. They sold two million common shares and raised nearly $40 million for future operations. That same year, Fu-Kuen Lin led a research team that cloned the erythropoietin gene. This protein stimulates red blood cell production within the kidney. Their work resulted in Epogen, which became the company's first major commercial product. In June 1984, Amgen partnered with Kirin Brewery Company to distribute Epogen in Japan while retaining United States rights. This joint venture later evolved into Kirin-Amgen in 2017.

    The company received FDA approval for Neupogen in February 1991. This drug prevented infections in patients whose immune systems were suppressed by cancer chemotherapy. Larry Souza and his team subsequently cloned granulocyte colony-stimulating factor. In March 1993, Amgen opened a new manufacturing facility in Puerto Rico. It eventually became the company's flagship site. By 1994, Amgen received the National Medal of Technology and Innovation from the Department of Commerce.

  • Amgen generates billions in annual revenue through specific therapeutic drugs targeting distinct medical conditions. Prolia and XGEVA combined brought in $6.7 billion in total revenues during 2024. These proteins treat osteoporosis and bone diseases affecting post-menopausal women and cancer patients. Enbrel generated $3.3 billion in 2024 revenues alone. It treats various forms of autoimmune diseases including rheumatoid arthritis. Repatha contributed $2.3 billion to 2024 revenues as a treatment for hyperlipidemia or high cholesterol levels.

    Otezla produced $2.1 billion in 2024 revenues while treating psoriasis and psoriatic arthritis. Tepezza added $1.8 billion to the portfolio by treating Graves' ophthalmopathy. Evenity generated $1.5 billion in 2024 revenues to address osteoporosis cases. Kyprolis also contributed $1.5 billion annually to treat certain types of cancer. Nplate generated $1.4 billion in 2024 revenues to regulate platelet production. Aranesp brought in $1.3 billion last year to stimulate erythropoiesis or red blood cell formation.

    The company receives approximately 80% of its revenues from sales to three large U.S. drug wholesalers. McKesson Corporation, Cencora, and Cardinal Health handle these massive distribution channels. Amgen currently maintains seventeen clinical programs underway in Phase III trials. Eight additional programs exist in Phase II stages while nineteen others remain in Phase I testing. A pipeline candidate named MariTide aims to serve as an anti-obesity medication administered once per month.

  • Amgen expanded its market share through aggressive acquisition strategies targeting competitors in rare diseases. In October 2022, the company acquired ChemoCentryx for $3.7 billion in an all-cash deal. This purchase included Tavneos, a drug treatment for rare autoimmune vasculitis conditions. The following year, Amgen purchased Horizon Therapeutics for $27.8 billion. This specialized firm developed drugs specifically designed for rare disease populations.

    Earlier acquisitions shaped the company's trajectory significantly over two decades. Immunex Corporation joined Amgen in 2002 bringing valuable assets into the portfolio. Onyx Pharmaceuticals was acquired in 2013 to strengthen cancer research capabilities. BioVex Group Inc became part of the organization in 2011 after being purchased outright. Micromet Inc entered the fold in 2012 alongside deCODE genetics and KAI Pharmaceuticals.

    In April 2021, Amgen acquired Five Prime Therapeutics and its lead candidate bemarituzumab for $1.9 billion. Rodeo Therapeutics followed in March 2021 with a $720 million acquisition price. These purchases allowed Amgen to diversify its pipeline beyond established blockbuster drugs. The strategy focused on acquiring companies with promising late-stage candidates rather than early-stage research projects.

  • Amgen constructed new biomanufacturing facilities across multiple continents to support growing production needs. Construction began on a plant in West Greenwich, Rhode Island during July 2018. Another facility opened near Dublin, Ireland in March 2011 to serve European markets. Next-generation biomanufacturing construction completed in Singapore later that same year. These sites handle complex protein drug synthesis and purification processes required for global distribution.

    New Albany, Ohio received a $900 million expansion announced in April 2025. Holly Springs, North Carolina broke ground on a new manufacturing facility in March 2022. A $600 million research center planned for Thousand Oaks, California was scheduled for September 2025 completion. The Puerto Rico site established in 1993 remains the company's flagship manufacturing location today.

    These facilities enable Amgen to produce billions of doses annually while maintaining strict quality standards. The company utilizes advanced technologies including machine learning services provided by Amazon Web Services. This partnership helps discover medicines and optimize the manufacturing process through data analysis. Global operations now span dozens of countries with headquarters remaining in Thousand Oaks, California.

Up Next

Common questions

When was Amgen founded and by whom?

Amgen was established in April 1980 by a small group of venture capitalists who initially named the entity Applied Molecular Genetics. George Rathmann became the first president and chief executive officer in October 1980.

What were the major financial results for Amgen products in 2024?

Prolia and XGEVA combined generated $6.7 billion in total revenues during 2024 while Enbrel brought in $3.3 billion alone. Repatha contributed $2.3 billion to 2024 revenues as a treatment for hyperlipidemia or high cholesterol levels.

Which companies did Amgen acquire between 2021 and 2025?

In October 2022, the company acquired ChemoCentryx for $3.7 billion and purchased Horizon Therapeutics for $27.8 billion the following year. Earlier acquisitions included Five Prime Therapeutics in April 2021 and Rodeo Therapeutics in March 2021.

Where is the headquarters of Amgen located today?

The global operations of Amgen span dozens of countries with headquarters remaining in Thousand Oaks, California. The Puerto Rico site established in 1993 remains the company's flagship manufacturing location today.

Why did Amgen face legal challenges regarding Aranesp in December 2012?

Amgen pleaded guilty and agreed to pay $150 million in criminal penalties because it sold the drug for off-label uses at dosages rejected by regulators. An additional $612 million resolved eleven related whistleblower complaints concerning improper marketing of Aranesp.

All sources

139 references cited across the entry

  1. 1web2025 Annual Report (Form 10-K)U.S. Securities and Exchange Commission — February 13, 2026
  2. 3webFortune: AmgenFortune
  3. 6newsAmgen's troubles loom large over hometownDaniel Costello — August 9, 2007
  4. 7webA history of: AmgenRobin Walsh — October 27, 2010
  5. 8journalGeorge Rathmann 1927–2012June 7, 2012
  6. 9newsGeorge Rathmann, Amgen Chief, Dies at 84Andrew Pollack — April 24, 2012
  7. 11newsAmgen: This Beaten Down Blue Chip Is Priced To OwnNicholas Ward — April 21, 2019
  8. 17newsSouza to Run Research at Biotech King AmgenBarbara Murphy — May 20, 1997
  9. 18journalG-CSF: From granulopoietic stimulant to bone marrow stem cell mobilizing agentLinda J. Bendall et al. — August 2014
  10. 21newsAn F.D.A. Approval for AmgenAndrew Pollack — February 22, 1991
  11. 23newsAmgen, Phone Entrepreneur Win Medal of TechnologyAaron Nathans — September 16, 1994
  12. 24newsA Biotech Wonder Grows UpSeptember 3, 2001
  13. 25newsAmgen names new CEOCNN — May 11, 2000
  14. 27webDrug Approval PackageFood and Drug Administration
  15. 28webHIGHLIGHTS OF PRESCRIBING INFORMATION – Prolia (denosumab)Food and Drug Administration — June 2010
  16. 29press releaseFDA Approves Xgeva to Help Prevent Cancer-Related Bone InjuryPR Newswire — November 19, 2010
  17. 30newsAmgen to buy Pfizer plantMarch 11, 2011
  18. 35newsAmgen launches $200m biomanufacturing facility in SingaporeZachary Brennan — November 21, 2014
  19. 36journalFDA Approval: BlinatumomabDonna Przepiorka et al. — September 15, 2015
  20. 41newsAmgen's Humira biosim, Amjevita, passes FDA milestone on long road to marketTracy Staton — Questex — September 23, 2016
  21. 42newsAmgen secures FDA approval for hormone drugJacob Bell — Informa — February 8, 2017
  22. 44newsAmgen breaks ground on $200M next-gen biopharma plant in Rhode IslandJoseph Keenan — Questex — August 1, 2018
  23. 51newsFDA Grants AMG 510 Fast Track Designation for KRAS G12C+ NSCLCLisa Astor — targetedonc.com — September 9, 2019
  24. 56newsEli Lilly, Amgen join forces to scale production of COVID-19 antibody cocktailsKyle Blankenship — Questex — September 17, 2020
  25. 59newsCOVID R&D Alliance launches trial of Amgen, UCB, Takeda drugsDeena Beasley — November 30, 2020
  26. 60newsAmgen cuts Cytokinetics loose after heart drug disappointmentJonathan Gardner — November 23, 2020
  27. 62newsAmgen plans 2020 filing for FDA approval of KRAS drug sotorasibNick Paul Taylor — December 8, 2020
  28. 65press releaseAmgen Successfully Completes Acquisition Of Five Prime TherapeuticsPR Newswire — April 16, 2021
  29. 70press releaseAmgen to Acquire Rodeo Therapeutics CorporationPR Newswire — March 30, 2021
  30. 73newsSotorasib Earns Approval in Japan for KRAS G12C+ NSCLCAudrey Sternberg — cancernetwork.com — January 20, 2022
  31. 76newsAmgen to invest $100 million in SoftBank-backed NeumoraManas Mishra — October 7, 2021
  32. 78newsAmgen, AstraZeneca score FDA nod for blockbuster hopeful asthma drug TezspireKevin Dunleavy — Questex — December 20, 2021
  33. 79newsU.S. FDA approves expanded use of Amgen's psoriasis drugDania Nadeem — December 20, 2021
  34. 83newsAmgen partners with Arrakis to develop drugs aimed at RNANed Pagliarulo — Informa — January 11, 2022
  35. 86newsAmgen Issues 'Green Bond'Antonio Pequeño IV — February 23, 2022
  36. 87newsAmgen Mulls More Green Bonds After 'Robust Interest' in DebutDavid Caleb Mutua — March 29, 2022
  37. 89newsAmgen Breaks Ground on NC Biomanufacturing FacilityJohn Sterling — March 11, 2022
  38. 90newsNew Cancer Drug Beats Chemotherapy in StudyJoseph Walker — September 12, 2022
  39. 91newsAmgen to Buy ChemoCentryx for $3.7 BillionJoseph Walker — August 4, 2022
  40. 92press releaseAMGEN SUCCESSFULLY COMPLETES ACQUISITION OF CHEMOCENTRYXPR Newswire — October 20, 2022
  41. 93newsAmgen completes purchase of ChemoCentryx for $3.7 billionI-Chun Chen — October 21, 2022
  42. 95newsAmgen dives deeper into rare disease drugs with $27.8 BLN Horizon dealManas Mishra et al. — December 12, 2022
  43. 97newsAmgen, AZ Tezspire sinusitis data invite 'best-in-disease' talkAngus Liu — Questex — March 3, 2025
  44. 103newsAmgen to build $600M research center in Thousand OaksTony Biasotti — September 3, 2025
  45. 104newsAmgen to Acquire Synergen in $239-Million Biotech DealDavid Olmos — November 19, 1994
  46. 105newsAmgen Agrees to Buy Drug Maker KinetixBarbara Murphy — October 24, 2000
  47. 110newsAmgen to buy Celgene psoriasis drug Otezla for $13.4 billionMichael Erman et al. — August 26, 2019
  48. 114newsHorizon acquires Viela Bio for $3B in a windfall for AstraZenecaJacob Bell et al. — Informa — February 1, 2021
  49. 126newsF.D.A. Approves New Version of Amgen DrugAndrew Pollack — September 19, 2001
  50. 128newsFDA approves Amgen's injected immunotherapy for melanomaBill Berkrot — October 27, 2015
  51. 130newsU.S. FDA approves Amgen's blood platelet boosterSusan Heavey — August 22, 2008
  52. 131journalRomiplostim for the treatment of chronic immune (idiopathic) thrombocytopenic purpuraFaranak Jamali et al. — July 2009
  53. 133newsNew FDA ApprovalsMay 1, 2004
  54. 135journalFDA drug approval summary: panitumumab (Vectibix)Ruthann M. Giusti et al. — May 2007
  55. 136press releaseBiovitrum and Amgen Announce Close of Product Acquisition DealGlobeNewswire — December 16, 2008