Amgen
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.
The company faced significant legal challenges regarding marketing practices and patent disputes throughout its history. In December 2012, Amgen pleaded guilty and agreed to pay $150 million in criminal penalties. An additional $612 million resolved eleven related whistleblower complaints concerning improper marketing of Aranesp. The United States Department Justice stated that Amgen sold the drug for off-label uses at dosages rejected by regulators.
Recent antitrust rulings have further complicated the company's financial landscape. A jury ruled in May 2025 that Amgen owes Regeneron $406 million for engaging in anticompetitive practices. This decision concerned sales tactics used to increase Repatha market share against Praluent competitors. The court found evidence suggesting Amgen manipulated pricing strategies to disadvantage rival cholesterol-reduction drugs.
Patent validity has also been a recurring battleground for the biopharmaceutical giant. In April 2020, the United States Court of Appeals upheld two Amgen patents describing Enbrel manufacturing methods. This affirmed an August 2019 decision rejecting Sandoz's attempt to invalidate those intellectual property rights. Such legal victories protect revenue streams from biosimilar competitors entering the market.
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
Continue Browsing
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.