GSK vs Sanofi: Founders, CEOs and History
GSK was founded in 1715 by Silvanus Bevan, Joseph Nathan, John K. Smith and is led by Luke Miels. Sanofi was founded in 2004 by Jean-François Dehecq, René Sautier and is led by Belén Garijo.
Company facts
Founders
GSK
Silvanus Bevan
Silvanus Bevan was a Quaker apothecary who opened a pharmacy at Plough Court in the City of London in 1715. The business later became Allen & Hanburys, a respiratory-medicine specialist that Glaxo acquired in 1958, which is why GSK dates its history to 1715.
Joseph Nathan
Joseph Nathan emigrated from London to New Zealand and founded a general trading business in Wellington. In 1904 the firm began producing dried milk at Bunnythorpe and sold it as baby food under the Glaxo name.
John K. Smith
John K. Smith opened a drugstore in Philadelphia in 1830. Mahlon Kline joined the business as a bookkeeper in 1865, it became Smith, Kline & Co. in 1875, and Smith, Kline & French after acquiring French, Richards & Co. in 1891.
Mahlon Kline
Mahlon Kline joined John K. Smith's Philadelphia drug business as a bookkeeper in 1865 and became a partner as it grew into a wholesale and manufacturing company, renamed Smith, Kline & Co. in 1875.
Henry Wellcome
Henry Wellcome was a US-born pharmacist who co-founded Burroughs Wellcome & Co. with Silas Burroughs in London in 1880. The company popularised compressed tablets under the 'Tabloid' trademark and later funded major research laboratories.
Sanofi
Jean-François Dehecq
Jean-François Dehecq led Sanofi from its creation as Elf Aquitaine's health subsidiary in 1973. He drove the 1999 merger with Synthélabo and the 2004 takeover of Aventis, served as CEO of Sanofi-Aventis until the end of 2006 and remained chairman until 2010.
René Sautier
René Sautier is credited alongside Jean-François Dehecq with setting up Sanofi as Elf Aquitaine's pharmaceutical arm in 1973. Public records on his later role are limited.
CEOs and their tenures
GSK
- Jean-Pierre Garnier2000–2008
Former Chief Executive Officer
Garnier executed one of the largest corporate mergers in pharmaceutical history, effectively creating the modern GSK conglomerate.
Source - Andrew Witty2008–2017
Former Chief Executive Officer
Witty provided steady leadership during a period of significant macroeconomic volatility following the 2008 financial crisis.
Source - Emma Walmsley2017–2025
Former Chief Executive Officer
Walmsley modernized a sprawling, inefficient corporate giant, transforming GSK into a focused, agile biopharmaceutical enterprise.
Source - Luke Miels2026–present
Chief Executive Officer
Joined GSK in 2017 as President of Global Pharmaceuticals and later served as Chief Commercial Officer before succeeding Emma Walmsley on January 1, 2026.
Source
Sanofi
- Paul Hudson2019–2026
Former Chief Executive Officer
Grew Dupixent into a ~$17.7B (EUR15.7B) product; the board did not renew his mandate in February 2026 amid concerns over pipeline productivity.
Source - Belén Garijo2026–present
Chief Executive Officer
The board hired her to strengthen execution discipline and capital allocation. She previously led Merck KGaA and worked at Sanofi for 15 years.
Source - Olivier Charmeil2026–2026
Interim Chief Executive Officer
Provided continuity during the leadership transition.
Source
Timeline: GSK and Sanofi side by side
1715GSK
Silvanus Bevan opens Plough Court pharmacy
Silvanus Bevan opens a pharmacy at Plough Court in London, the business that later became Allen & Hanburys and GSK's oldest root.
1830GSK
John K. Smith opens a Philadelphia drugstore
John K. Smith's Philadelphia drugstore is the start of the business that became Smith, Kline & French.
1880GSK
Burroughs Wellcome & Co. founded
Henry Wellcome and Silas Burroughs found Burroughs Wellcome & Co. in London.
1904GSK
Glaxo dried milk launched in New Zealand
Joseph Nathan & Co. begins producing dried milk at Bunnythorpe, New Zealand, sold under the Glaxo name.
1958GSK
Glaxo acquires Allen & Hanburys
Glaxo buys Allen & Hanburys, bringing the Plough Court lineage and a respiratory business into the group.
1973Sanofi
Sanofi created inside Elf Aquitaine
The French oil group sets up Sanofi as its healthcare subsidiary.
1995GSK
Glaxo merges with Wellcome
Glaxo acquires Wellcome plc to form Glaxo Wellcome.
1999Sanofi
Sanofi-Synthélabo formed
Sanofi merges with L'Oréal's pharmaceutical unit Synthélabo.
2000GSK
GlaxoSmithKline formed
Glaxo Wellcome and SmithKline Beecham merge in December 2000 to create GlaxoSmithKline, headquartered in the UK.
2004Sanofi
Aventis takeover
Sanofi-Synthélabo wins a hostile bid for the larger Aventis, creating Sanofi-Aventis.
2011Sanofi
Genzyme acquired
Sanofi buys Genzyme for about $20.1 billion, adding rare disease therapies.
2015GSK
Consumer healthcare joint venture with Novartis
GSK and Novartis combine their consumer health businesses in a joint venture majority-owned by GSK, as part of an asset swap in which GSK sold its oncology portfolio to Novartis.
2017GSK
Shingrix approved; Emma Walmsley becomes CEO
Emma Walmsley becomes CEO in April 2017, and the FDA approves the Shingrix shingles vaccine in October 2017.
2017Sanofi
Dupixent approved
The FDA approves Dupixent for atopic dermatitis, starting Sanofi's largest growth franchise.
2019Sanofi
'Play to Win' strategy
New CEO Paul Hudson refocuses Sanofi on immunology, vaccines and specialty care.
2022GSK
Haleon demerged
GSK demerges its consumer health business as Haleon plc in July 2022 and shortens its name to GSK plc.
2023GSK
Arexvy approved
The FDA approves Arexvy in May 2023 as the first RSV vaccine for adults aged 60 and older.
2025GSK
Exdensur and Blenrep approved in the US
GSK wins US approvals including Blujepa (March), Blenrep (October) and the twice-yearly asthma biologic Exdensur (December 2025).
2025Sanofi
Opella control sold; Blueprint acquired
Sanofi sells a 50% controlling stake in Opella to CD&R in April and completes the Blueprint Medicines acquisition in July.
2026GSK
Luke Miels becomes CEO
Luke Miels succeeds Emma Walmsley as Chief Executive Officer on January 1, 2026.
2026GSK
Nuvalent acquisition completed
GSK completes its $10.6 billion acquisition of Nuvalent in July 2026, adding the lung-cancer drugs Jideytro and neladalkib.
2026Sanofi
Belén Garijo becomes CEO
The board ends Paul Hudson's tenure in February; Garijo takes over after the April 29 AGM.
Acquisitions
GSK
- Nuvalent2026$10.6B
- efimosfermin alfa (from Boston Pharmaceuticals)2025$1.2B
- IDRx2025$1B
- Sierra Oncology2022$1.9B
Sanofi
- Blueprint Medicines2025$9.1B
- Provention Bio2023$2.9B
- Genzyme2011$20.1B
- Aventis2004Undisclosed
Questions about GSK vs Sanofi
Who is the CEO of GSK plc and Sanofi S.A.?
GSK plc is led by Luke Miels and Sanofi S.A. is led by Belén Garijo. Both serve as the top executive responsible for the company's strategy, operations, and financial performance.
When was GSK plc founded vs Sanofi S.A.?
GSK plc was founded in 1715 — 289 years before Sanofi S.A., which was founded in 2004. GSK plc's longer operating history gives it a deeper track record but also potentially more institutional inertia compared to the younger Sanofi S.A..
How many employees does GSK plc have compared to Sanofi S.A.?
GSK plc employs approximately 66,800 people, while Sanofi S.A. employs approximately 74,846. Sanofi S.A. has the larger workforce at 74,846 employees, compared to GSK plc's 66,800. A higher headcount does not necessarily imply greater efficiency — it often reflects differences in business model (e.g., manufacturing vs. software).
Where are GSK plc and Sanofi S.A. headquartered?
GSK plc is headquartered in United Kingdom and Sanofi S.A. is headquartered in France. Their different home markets mean they may face different regulatory frameworks, tax regimes, and currency exposure.
Who founded GSK plc and Sanofi S.A.?
GSK plc was founded by Silvanus Bevan, Joseph Nathan, John K. Smith, Mahlon Kline, Henry Wellcome. Sanofi S.A. was founded by Jean-François Dehecq, René Sautier.
Which company has a longer operating history — GSK plc or Sanofi S.A.?
GSK plc has been operating for approximately 311 years, making it the more established of the two companies. Sanofi S.A. has been in operation for around 22 years. A longer operating history often signals greater institutional resilience and brand recognition, though it can also mean slower adaptation to new market conditions.
Figures come from each company's filings and the sources linked beside them. Amounts reported in another currency are shown in US dollars at an approximate rate and marked with ~. Back to the GSK vs Sanofi overview