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TESARO is an oncology-focused business within GlaxoSmithKline (GSK) with a highly qualified, international workforce that represents more than 20 nationalities. Our global headquarters are located in Waltham, Massachusetts, and our international headquarters are in Zug, Switzerland, with local offices serving countries across Europe.

North America

TESARO Global Headquarters

1000 Winter Street
Waltham, MA 02451 USA
+1 339 970 0900

TESARO US Medical Information

Click here to submit a Medical Inquiry
+1 844 4 TESARO (+1 844 483 7276)

TESARO Canada Medical Information

Click here to submit a Medical Inquiry
+1 800 387 7374
Map indicating the location of TESARO's global headquarters in Waltham, MA



In 2016, we founded our international headquarters in Zug, Switzerland, in the heart of Europe. A 30-kilometer (20-minute) train ride from Zurich, the Zug office is the hub of our international business, serving countries across Europe. Zug is recognized as a dynamic business location and is an international center for innovation and technology, especially in the life science sector.

In 2017, our international capabilities allowed us to successfully launch 2 medicines in Europe, and we continually strive to bring more cancer patients the therapies they need.

International Headquarters


Poststrasse 6
6300 Zug, Switzerland
+41 (0)41 588 08 55

TESARO International Medical Information

To request medical information or report an adverse event in Europe, please contact the relevant/appropriate office listed below.

Click here to submit a Medical Inquiry

European Offices

TESARO Bio Austria GmbH

Vienna, Austria

TESARO Bio Germany GmbH

Munich, Germany

TESARO Bio Spain S.L.U.

Madrid, Spain (Portugal)

TESARO Bio UK, Ireland, and Nordics

London, United Kingdom

TESARO Bio France & Benelux

Paris, France

TESARO Bio Italy S.r.l.

Rome, Italy

TESARO Bio Switzerland GmbH

Zug, Switzerland

Map indicating the locations of TESARO's international headquarters and European offices