1849–1950: Early history Pfizer was founded in 1849 as
Charles Pfizer & Company by
Charles Pfizer and
Charles F. Erhart, two cousins who had immigrated to the United States from
Ludwigsburg, Germany. The business produced chemical compounds, and was headquartered on Bartlett Street in
Williamsburg, Brooklyn, where it produced an
antiparasitic called
santonin. This was an immediate success, although it was production of
citric acid that led to Pfizer's growth in the 1880s. Pfizer continued to buy property in the area (by now the Williamsburg district of the city of
Brooklyn, New York and beginning in 1898, the
City of Greater New York) to expand its lab and factory, retaining offices on Flushing Avenue until the 1960s; the Brooklyn plant ultimately closed in 2009. Following its success with citric acid, Pfizer (at the now-demolished 295 Washington Avenue) and Erhart (at 280 Washington Avenue) established their main residences in the nearby
Clinton Hill district, known for its concentration of
Gilded Age wealth. In 1881, Pfizer moved its administrative headquarters to 81 Maiden Lane in
Manhattan, presaging the company's expansion to
Chicago, Illinois, a year later.
World War I caused a shortage of
calcium citrate. Pfizer imported the compound from Italy for the manufacture of citric acid, and due to the disruption in supply, the company began a search for an alternative. They found this in the form of a
fungus capable of fermenting sugar to citric acid. By 1919, the company was able to commercialize production of citric acid from this source. The company also embarked on a global
soil collection program related to improving production yields of penicillin which ultimately resulted in 135,000 samples. On June 2, 1942, the company incorporated under the
Delaware General Corporation Law. In 1972,
Edmund T. Pratt Jr. became CEO of the company, succeeding John Powers, Jr. In 1986, Pfizer acquired the worldwide rights to Zithromax (
azithromycin), a macrolide antibiotic that is recommended by the
Infectious Disease Society of America as a first line treatment for certain cases of community-acquired pneumonia, from
Pliva. In 1989, Pfizer scientists Peter Dunn and Albert Wood created Viagra (
sildenafil) for treating
high blood pressure and
angina, a chest pain associated with
coronary artery disease. In 1991, it was patented in the United Kingdom as a heart medication. Early trials for the medication showed that it did not work for the treatment of heart disease, but volunteers in the clinical trials had increased
erections several days after taking the drug. It was patented in the United States in 1996 and received approval by the
Food and Drug Administration in March 1998. In December 1998, Pfizer hired
Bob Dole as a spokesperson for the drug. The patents for Viagra expired in 2020. In 1991,
William C. Steere, Jr. became CEO, succeeding
Edmund T. Pratt Jr. In 1991 Pfizer also began marketing Zoloft (
sertraline), an
antidepressant of the
selective serotonin reuptake inhibitor (SSRI) class developed nine years earlier by Pfizer chemists
Kenneth Koe and Willard Welch. Sertraline is primarily prescribed for
major depressive disorder in adult
outpatients as well as
obsessive-compulsive disorder,
panic disorder, and
social anxiety disorder in both adults and children. In 2005, the year before it became a generic drug, sales were over $3billion and over 100million people had been treated with the drug. The patent for Zoloft expired in the summer of 2006. In 1996,
Eisai, in partnership with Pfizer, received
approval from the
Food and Drug Administration for
donepezil under the brand Aricept for treatment of
Alzheimer's disease; Pfizer also received approval for Norvasc (
amlodipine), an
antihypertensive drug of the dihydropyridine calcium channel blocker class. ), an
antidepressant In 1997, the company entered into a co-marketing agreement with
Warner–Lambert for Lipitor (
atorvastatin), a
statin for the treatment of
hypercholesterolemia. Although atorvastatin was the fifth
statin to be developed, clinical trials showed that atorvastatin caused a more dramatic reduction in
low-density lipoprotein pattern C (LDL-C) than the other statin drugs. Upon its patent expiration in 2011, Lipitor was the best-selling drug ever, with approximately $125billion in sales over 14.5 years.
2000–2010: Further expansion In 2001,
Henry McKinnell became CEO, replacing
William C. Steere, Jr. In 2002, The
Bill & Melinda Gates Foundation purchased stock in Pfizer. In 2004, the company received approval for Lyrica (
pregabalin), an
anticonvulsant and
anxiolytic medication used to treat
epilepsy,
neuropathic pain,
fibromyalgia,
restless leg syndrome, and
generalized anxiety disorder. The United States patent on Lyrica was challenged by generic manufacturers and was upheld in 2014, extending the expiration date to 2018. In July 2006,
Jeff Kindler was named CEO, replacing
Henry McKinnell. On December 3, 2006, Pfizer ceased development of
torcetrapib, a drug that increases production of
HDL, which reduces
LDL thought to be correlated to heart disease. During a
Phase III clinical trial involving 15,000 patients, more deaths than expected occurred in the group that took the medicine, and the
mortality rate of patients taking the combination of torcetrapib and Lipitor (82 deaths during the study) was 60% higher than those taking Lipitor alone (52 deaths during the study). Lipitor alone was not implicated in the results, but Pfizer lost nearly $1billion developing the failed drug and its stock price dropped 11% on the day of the announcement. Between 2007 and 2010, Pfizer spent $3.3million on investigations and legal fees and recovered about $5.1million, and had another $5million of pending recoveries from civil lawsuits against makers of
counterfeit prescription drugs. Pfizer has hired customs and narcotics experts worldwide to track down fakes and assemble evidence that can be used to pursue civil suits for
trademark infringement. In July 2008, Pfizer announced 275 job cuts at its manufacturing facility in
Portage, Michigan. Portage was previously the world headquarters of
Upjohn Company, which had been acquired as part of Pharmacia.
Acquisitions and mergers In June 2000, Pfizer acquired Warner-Lambert outright for $116billion. To satisfy conditions imposed by antitrust regulators at the
Federal Trade Commission, Pfizer sold off or transferred stakes in several minor products, including RID (a shampoo for treatment of
head lice, sold to
Bayer) and Warner-Lambert's antidepressant
Celexa (which competes with Zoloft). The acquisition created what was, at the time, the second-largest pharmaceutical company worldwide. In 2003, Pfizer merged with
Pharmacia, and in the process acquired
Searle and
SUGEN. Searle had developed Flagyl (
metronidazole), a
nitroimidazole antibiotic medication used particularly for
anaerobic bacteria and
protozoa. Searle also developed
celecoxib (Celebrex) a
COX-2 inhibitor and
nonsteroidal anti-inflammatory drug (NSAID) used to treat the
pain and
inflammation in
osteoarthritis,
acute pain in adults,
rheumatoid arthritis,
ankylosing spondylitis,
painful menstruation, and
juvenile rheumatoid arthritis.
SUGEN, a company focused on
protein kinase inhibitors, had pioneered the use of ATP-mimetic small molecules to block
signal transduction. The
SUGEN facility was shut down in 2003 by Pfizer, with the loss of more than 300 jobs, and several programs were transferred to Pfizer. These included
sunitinib (Sutent), a cancer medication which was approved for human use by the FDA in January 2006. A related compound, SU11654 (
Toceranib), was also approved for
cancer in dogs, and the
ALK inhibitor Crizotinib also grew out of a SUGEN program. In October 2006, the company announced it would acquire PowerMed. On October 15, 2009, Pfizer acquired
Wyeth for $68billion in cash and stock, including the assumption of debt, making Pfizer the largest pharmaceutical company in the world. The acquisition of Wyeth provided Pfizer with a
pneumococcal conjugate vaccine, trademarked
Prevnar 13; this is used for the prevention of invasive pneumococcal infections. The introduction of the original, 7-valent version of the vaccine, developed by
Wyeth in February 2000, led to a 75% reduction in the incidence of invasive pneumococcal infections among children under age5 in the United States. Pfizer introduced an improved version of the vaccine in 2010, for which it was granted a patent in India in 2017. Prevnar 13 provides coverage of 13 bacterial variants, expanding beyond the original 7-valent version.
2010–2020: Further discoveries and acquisitions In 2010,
Ian Read was named CEO. In February 2011, Pfizer announced the closure of its UK research and development facility (formerly also a manufacturing plant) in
Sandwich, Kent, which at the time employed 2,400 people. In March 2011, Pfizer acquired
King Pharmaceuticals for $3.6billion in cash. King produced emergency injectables such as the
EpiPen. On September 4, 2012, the FDA approved
bosutinib (Bosulif) for
chronic myelogenous leukemia (CML), a rare type of
leukemia and a blood and
bone marrow disease that affects primarily older adults. In November 2012, Pfizer received approval from the
Food and Drug Administration for Xeljanz, a
tofacitinib, for
rheumatoid arthritis and
ulcerative colitis. The drug had sales of $1.77billion in 2018, and in January 2019, it was the top drug in the United States for
direct-to-consumer advertising, passing
adalimumab (Humira). In 2023, the Institute for Clinical and Economic Review (ICER) identified Xeljanz (tofacitinib) as one of five high-expenditure drugs that experienced significant net price increases without new clinical evidence to justify the hikes. Specifically, Xeljanz's wholesale acquisition cost rose by 6%, leading to an additional $72 million in costs to U.S. payers. On February 1, 2013,
Zoetis, the Agriculture Division of Pfizer and later Pfizer Animal Health, became a
public company via an
initial public offering, raising $2.2billion. Later in 2013, Pfizer completed the
corporate spin-off of its remaining stake in
Zoetis. In September 2014, the company acquired Innopharma for $225million, plus up to $135million in milestone payments, in a deal that expanded Pfizer's range of generic and injectable drugs. On January 5, 2015, the company announced it would acquire a controlling interest in Redvax, expanding its vaccine portfolio targeting human
cytomegalovirus. In February 2015, the company received approval from the
Food and Drug Administration for
palbociclib (Ibrance) for treatment of certain types of
breast cancer. In March 2015, the company announced it would restart its collaboration with
Eli Lilly and Company surrounding the
Phase III trial of
Tanezumab. In May 2015, Pfizer and a
Bar-Ilan University laboratory announced a partnership based on the development of medical
DNA nanotechnology. In June 2015, the company acquired Nimenrix and Mencevax,
meningococcal vaccines, from GlaxoSmithKline for around $130million. In September 2015, Pfizer acquired
Hospira for $17billion, including the assumption of debt.
Hospira was the largest producer of generic injectable pharmaceuticals in the world. On November 23, 2015, Pfizer and
Allergan announced a planned $160billion merger, in the largest pharmaceutical deal ever and the third largest corporate merger in history. The proposed transaction contemplated that the merged company maintain Allergan's
Republic of Ireland domicile, resulting in the new company being subject to
corporation tax at the relatively low rate of 12.5%. The deal was to constitute a
reverse merger, whereby Allergan acquired Pfizer, with the new company then changing its name to "Pfizer, plc". On April 6, 2016, Pfizer and Allergan terminated the merger agreement after the
Obama administration and the
United States Department of the Treasury introduced new laws intended to limit
corporate inversions (the extent to which companies could move their headquarters overseas in order to reduce the amount of taxes they pay). In June 2016, the company acquired Anacor Pharmaceuticals for $5.2billion, expanding its portfolio in both inflammation and immunology drugs areas. In August 2016, the company made a $40million bid for the assets of BIND Therapeutics, which was in
bankruptcy. The same month, the company acquired Bamboo Therapeutics for $645million, expanding its gene therapy offerings. In September 2016, the company acquired cancer drug-maker
Medivation for $14billion. In October 2016, the company licensed the anti-
CTLA4 monoclonal antibody, ONC-392, from OncoImmune. In November 2016, Pfizer funded a $3,435,600 study with the
CDC Foundation to research "screen-and-treat" strategies for
cryptococcal disease in
Botswana. In December 2016, Pfizer acquired
AstraZeneca's small-molecule antibiotics business for $1.575 billion. In January 2018, Pfizer announced that it would end its work on research into treatments for
Alzheimer's disease and
Parkinsonism (a symptom of
Parkinson's disease and other conditions). The company said about 300 researchers would lose their jobs. In July 2018, the
Food and Drug Administration approved
enzalutamide, developed by Pfizer and
Astellas Pharma for patients with
castration-resistant
prostate cancer. In August 2018, Pfizer signed an agreement with
BioNTech to conduct joint research and development activities regarding
mRNA-based
influenza vaccines. In October 2018, effective January 1, 2019,
Albert Bourla was promoted to CEO, succeeding
Ian Read, his mentor. In July 2019, the company acquired Therachon for up to $810million, expanding its rare disease portfolio through Therachon's recombinant human fibroblast growth factor receptor 3 compound, aimed at treating conditions such as
achondroplasia. Also in July, Pfizer acquired
Array Biopharma for $10.6billion, boosting its oncology pipeline. In August 2019, Pfizer merged its consumer health business with that of GlaxoSmithKline, into a
joint venture owned 68% by GlaxoSmithKline and 32% by Pfizer, with plans to make it a
public company. The transaction built on a 2018 transaction where GlaxoSmithKline acquired
Novartis' stake in the GSK-Novartis consumer healthcare joint business. The transaction followed negotiations with other companies including
Reckitt Benckiser,
Sanofi,
Johnson & Johnson, and
Procter & Gamble. In September 2019, Pfizer initiated a study with the
CDC Foundation to investigate the tracking of
healthcare-associated infections, scheduled to run through to June 2023. The $125 million initiative was launched by the
Bill & Melinda Gates Foundation in partnership with
Mastercard and
Wellcome Trust, with additional funding announced shortly after from
Chan Zuckerberg Initiative,
UK Foreign, Commonwealth and Development Office and
Madonna. The following month, the
Foundation for the National Institutes of Health announced the Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV) public-private partnership to develop a coordinated research strategy for prioritizing and speeding up development of COVID-19 vaccines and pharmaceutical products. Pfizer joined the partnership as an industry "leadership organization", and participated as a collaborator in ACTIV-led clinical trials. CEO
Albert Bourla attended the
GAVI COVAX AMC 2021 Investment Opportunity Launch Event, otherwise named One World Protected, on April 15, 2021. In Canada, Pfizer endorsed the use of a
vaccine passport mobile app developed by CANImmunize in order to record and track status of COVID-19 vaccination. As the scale of the
COVID-19 pandemic became apparent, Pfizer partnered with BioNTech to study and develop
COVID-19 mRNA vaccine candidates. Unlike many of its competitors, Pfizer took no initial research funds from the United States'
Operation Warp Speed vaccine development program, instead choosing to invest roughly $2 billion of its own funds. Pfizer CEO Albert Bourla has said that he declined money from Operation Warp Speed to avoid government intervention, stating later that "when you get money from someone that always comes with strings. They want to see how we are going to progress, what type of moves you are going to do. They want reports. And also, I wanted to keep Pfizer out of politics, by the way." In May 2020, Pfizer began testing four different
COVID-19 vaccine variations using
lipid nanoparticle technology provided by Canadian biotechnology company
Acuitas Therapeutics. Vaccines were injected into the first human participants in the U.S. in early May. In July 2020, Pfizer and BioNTech announced that two of the partners' four
mRNA vaccine candidates had won fast track designation from the
FDA. The company began PhaseII-III testing on 30,000 people in the last week of July 2020 and was slated to be paid $1.95billion for 100million doses of the vaccine by the US government. In September 2020, Pfizer and BioNTech announced that they had completed talks with the European Commission to provide an initial 200million vaccine doses to the EU, with the option to supply another 100million doses at a later date. On November 9, 2020, Pfizer announced that BioNTech's COVID-19 vaccine, tested on 43,500 people, was found to be 90% effective at preventing symptomatic COVID-19. The efficacy was updated to 95% a week later, described as a "really a spectacular number" and made Pfizer and BioNTech the first companies to develop and test a working vaccine for COVID-19. In November and December 2020, regulators in various countries approved Pfizer's vaccine for emergency use.
Development of oral antivirals In November 2021, Pfizer launched a new COVID-19 oral antivirus treatment known as
Paxlovid. In January 2022, the Pfizer CEO
Albert Bourla confirmed that the trial results of a fourth dose were pending until March 2022. He said that the firm was setting up a collaboration to develop an anti-COVID pill treatment along with a French company,
Novasep. He also said the COVID vaccine was "safe and efficient" for children. In May 2022, reports emerged of patients experiencing "rebound" symptoms after completing a five-day course of Paxlovid. The FDA responded by announcing they had performed additional analyses of the drug's clinical trial data, and decided against changing its recommendations. U.S. President
Joe Biden and Dr.
Anthony Fauci were both reported to experience this rebound syndrome in the months that followed, while continuing to recommend the drug for those who may benefit from it.
Corporate developments and acquisitions In September 2020, the company acquired a 9.9% stake in CStone Pharmaceuticals for $200million (HK$1.55billion), helping to commercialise its anti-
PD-L1 monoclonal antibody, CS1001. In October 2020, the company acquired Arixa Pharmaceuticals. In November 2020, using a
Reverse Morris Trust structure, Pfizer merged its off-patent branded and
generic drug business, known as Upjohn, with
Mylan to form
Viatris, owned 57% by Pfizer shareholders. On January 5, 2021, Pfizer introduced a new
logo. In April 2021, Pfizer acquired Amplyx Pharmaceuticals and its anti-fungal compound
fosmanogepix (APX001). In August, the company announced it would acquire Trillium Therapeutics Inc and its immuno-oncology portfolio for $2.3 billion. In March 2022, the company acquired
Arena Pharmaceuticals for $6.7 billion in cash. In June 2022, the company acquired ReViral Ltd, for up to $525 million, gaining access to experimental drugs used to combat
respiratory syncytial virus infections. In October 2022, the company acquired Biohaven Pharma and its
calcitonin gene-related peptide programs for $11.6 billion. It also acquired Global Blood Therapeutics for $5.4 billion, boosting Pfizer's rare disease business. In April 2023, Pfizer moved its world headquarters from
42nd Street in
Midtown Manhattan to the Spiral at
Hudson Yards. In December 2023, the company acquired
Seagen, a pioneer of
antibody–drug conjugates for the treatment of cancer, for $43billion. In March 2025, the company sold its entire stake in Haleon for $3.24 billion to institutional investors.
Tariffs In October 2025, Pfizer entered an agreement with the
Trump administration to voluntarily lower US drug prices, which included a three-year exemption from pharmaceutical-specific tariffs, as long as the firm further invests in domestic manufacturing. Pfizer pledged to put $70 billion into US manufacturing and research.
Partnership with Flagship Pioneering In July 2024, Pfizer and Flagship Pioneering announced an "Innovation Supply Chain" partnership to co-develop 10 drug candidates. Each party committed $50 million upfront, leveraging Flagship's ecosystem of over 40 startups to align with Pfizer's priorities. Pfizer will fund the selected programs and has the option to license or acquire assets, with potential success milestones and royalties reaching up to $700 million per commercialized drug. Two programs, focused on
obesity and
cardiovascular diseases, have already been initiated. The partnership represents a new model in pharmaceutical R&D, focusing on early collaboration with startups to streamline drug development. For startups, the model provides an opportunity for early engagement with pharmaceutical companies, offering potential funding and reduced uncertainty in development programs.
Expanding AI Collaboration for Clinical Trials with Saama Saama and Pfizer reached an expanded multi-year agreement to integrate AI-driven solutions across Pfizer's R&D portfolio, building on their 2020 partnership. Initially the partnership focused on automating data review processes with the Smart Data Quality (SDQ) platform — developed during Pfizer's COVID-19 vaccine trials — the partnership as of 2024 scales to streamline data review and accelerate regulatory submissions across global studies. The expanded collaboration introduces Saama's Biometrics Research and Analysis Information Network, enabling faster statistical programming, biostatistics workflows, and submission-ready outputs. == Acquisitions ==