• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
Health

Pfizer, Allergan Confirm $160 Billion Merger Deal

By
Geoffrey Smith
Geoffrey Smith
and
Claire Groden
Claire Groden
Down Arrow Button Icon
By
Geoffrey Smith
Geoffrey Smith
and
Claire Groden
Claire Groden
Down Arrow Button Icon
November 23, 2015, 8:00 AM ET
Pfizer In Merger Talks With Allergan PLC
NEW YORK, NY - OCTOBER 29: The Pfizer headquarters in New York City stands in the heart of Manhattans business district on October 29, 2015 in New York City. Ireland-based Allergan confirmed October 29, that it has been approached by the U.S. drug company Pfizer and is in talks regarding a potential deal. These are just the latest two pharmaceutical companies to start early dealmaking talks. (Photo by Spencer Platt/Getty Images)Photograph by Spencer Platt—Getty Images

Pharmaceutical giants Pfizer and Allergan confirmed Monday they will merge to form the world’s biggest drug company by sales, in a deal that is mostly, if not exclusively, about tax.

The deal values the combined company at $160 billion (including debt), and, as expected, is structured in such a way as to reduce Pfizer’s tax bill by moving its domicile out of the U.S. to Ireland. The companies said they expect the company to have an effective tax rate of 17% to 18% in the first full year after closing, compared to around 25% for Pfizer at present.

The deal is the largest so-called inversion deal ever. An inversion occurs when a U.S. company merges with a foreign company and reincorporates overseas in order to avoid American corporate taxes. Allergan is based in Dublin, and analysts say that the lower tax rate available is one of the most powerful forces underpinning the merger.

Despite the big valuation, not much cash will change hands. Pfizer (PFE) shareholders will get one share in the new company for every one they currently hold, while Allergan (AGN) shareholders will get 11.3 shares for each Allergan share. That gives the owners of Pfizer an effective 56% stake in the combined entity, and Allergan holders 44%. Pfizer shareholders can elect to receive cash instead of new shares, but only up to a combined value of $12 billion. (They’ll have to accept the remainder in shares.)

The combined company will remain in all other aspects essentially an American one, with both its primary stock exchange listing and its corporate headquarters in New York City. Pfizer CEO Ian Read will lead the company, with Allergan CEO Brent Saunders assuming the titles of president and chief operating officer.

The portfolio of the new company will include Botox, Viagra, the Prevnar pneumonia vaccine, and treatments for ailments including Alzheimer’s and rheumatoid arthritis.

The combined company could initially have annual sales of over $65 billion, but there has been speculation that the merger could quickly be followed by a spinoff of some lower-margin businesses, including drugs that have lost patent protection. Allergan already agreed to spin off its generics division to Israel-based Teva Pharmaceuticals.

The two companies said they expect to wring over $2 billion a year worth of increased efficiencies out of the deal within three years. Although the deal will dilute Pfizer’s earnings per share in the first year, it will boost them by over 10% by 2019 and just under 20% by 2020, the companies said. That assumes continued share buybacks, funded from an estimated operating cash flow of over $25 billion a year by 2018.

[fortune-brightcove videoid=4616335766001]

About the Authors
By Geoffrey Smith
See full bioRight Arrow Button Icon
By Claire Groden
See full bioRight Arrow Button Icon

Latest in Health

HealthAffordable Care Act (ACA)
A Wisconsin couple was paying $2 a month for an ACA health plan. But as subsidies expire, it’s soaring to $1,600, forcing them to downgrade
By Ali Swenson and The Associated PressDecember 13, 2025
6 hours ago
Julian Braithwaite is the Director General of the International Alliance for Responsible Drinking
CommentaryProductivity
Gen Z is drinking 20% less than Millennials. Productivity is rising. Coincidence? Not quite
By Julian BraithwaiteDecember 13, 2025
7 hours ago
Nicholas Thompson
C-SuiteBook Excerpt
I took over one of the most prestigious media firms while training for an ultramarathon. Here’s what I learned becoming CEO of The Atlantic
By Nicholas ThompsonDecember 13, 2025
9 hours ago
Healthmeal delivery
Factor Meals Review 2025: Tester Approved
By Christina SnyderDecember 12, 2025
24 hours ago
Donald Trump
HealthHealth Insurance
‘Tragedy in the making’: Top healthcare exec on why insurance will spike to subsidize a tax cut to millionaires and billionaires
By Nick LichtenbergDecember 12, 2025
1 day ago
HelloFresh meal delivery service.
Healthmeal delivery
HelloFresh Review : We Tasted Everything so You Don’t Have To
By Christina SnyderDecember 12, 2025
1 day ago

Most Popular

placeholder alt text
Economy
Tariffs are taxes and they were used to finance the federal government until the 1913 income tax. A top economist breaks it down
By Kent JonesDecember 12, 2025
1 day ago
placeholder alt text
Success
Apple cofounder Ronald Wayne sold his 10% stake for $800 in 1976—today it’d be worth up to $400 billion
By Preston ForeDecember 12, 2025
1 day ago
placeholder alt text
Success
40% of Stanford undergrads receive disability accommodations—but it’s become a college-wide phenomenon as Gen Z try to succeed in the current climate
By Preston ForeDecember 12, 2025
1 day ago
placeholder alt text
Economy
The Fed just ‘Trump-proofed’ itself with a unanimous move to preempt a potential leadership shake-up
By Jason MaDecember 12, 2025
24 hours ago
placeholder alt text
Economy
For the first time since Trump’s tariff rollout, import tax revenue has fallen, threatening his lofty plans to slash the $38 trillion national debt
By Sasha RogelbergDecember 12, 2025
1 day ago
placeholder alt text
Success
Apple CEO Tim Cook out-earns the average American’s salary in just 7 hours—to put that into context, he could buy a new $439,000 home in just 2 days
By Emma BurleighDecember 12, 2025
1 day ago
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • Future 50
  • World’s Most Admired Companies
  • See All Rankings
Sections
  • Finance
  • Leadership
  • Success
  • Tech
  • Asia
  • Europe
  • Environment
  • Fortune Crypto
  • Health
  • Retail
  • Lifestyle
  • Politics
  • Newsletters
  • Magazine
  • Features
  • Commentary
  • Mpw
  • CEO Initiative
  • Conferences
  • Personal Finance
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
About Us
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map

© 2025 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.