Tesaro

Tesaro, Inc. was an American biopharmaceutical company headquartered in Waltham, Massachusetts, and focused on the development and commercialization of medicines for cancer. Founded in 2010, the company operated as an oncology specialist rather than as a diversified pharmaceutical group. Its work included therapies intended to address cancer treatment support needs as well as antineoplastic medicines designed around emerging molecular and immune-oncology approaches. Tesaro's first commercial product was Varubi, the brand name for rolapitant. The medicine was approved by the United States Food and Drug Administration in October 2015 for the prevention of chemotherapy-induced nausea and vomiting. This approval gave Tesaro an initial commercial presence while the company continued developing its more strategically important oncology pipeline. The company's best-known product was Zejula, the brand name for niraparib. Niraparib is a PARP inhibitor developed for ovarian cancer and other potential oncology applications. The FDA granted the medicine priority review during its regulatory process, and Tesaro received approval for Zejula in March 2017 for the treatment of ovarian cancer. Zejula became the central product associated with Tesaro and represented the company's effort to establish a commercially meaningful presence in targeted cancer treatment. Tesaro also maintained a development portfolio that included additional formulations and investigational medicines. Rolapitant was being studied in an intravenous form for chemotherapy-induced nausea and vomiting, while niraparib was investigated in other cancer settings, including breast cancer. The company also advanced the programs later associated with dostarlimab and other investigational oncology candidates. Dostarlimab, subsequently commercialized by GlaxoSmithKline as Jemperli, received United States FDA approval in 2023 for a specified population of adults with mismatch repair-deficient recurrent or advanced endometrial cancer after prior platinum-containing treatment, subject to the approved indication and diagnostic requirements. By 2016, Tesaro had 286 full-time employees, including 59 employees with a PhD or MD, reflecting its research-driven operating model. In 2017, reports indicated that the company was exploring a sale. GlaxoSmithKline announced an agreement to acquire Tesaro on December 3, 2018, for approximately $5.1 billion. The transaction was completed on January 22, 2019. Following the acquisition, Tesaro ceased to operate as an independent public biopharmaceutical company, while key assets such as Zejula and Jemperli became part of GSK's oncology portfolio. The Tesaro name therefore primarily refers to a former standalone oncology company and the business platform acquired by GSK.

Tesaro was established in 2010 in the United States as a biopharmaceutical company dedicated to oncology. Its business model was built around discovering, developing, and commercializing medicines for cancer, with an emphasis on products that could address both direct treatment needs and complications associated with chemotherapy. The company was based in Waltham, Massachusetts, a location within the biotechnology and pharmaceutical ecosystem of the greater Boston area. The company reached its first commercial milestone in October 2015, when the United States Food and Drug Administration approved Varubi, or rolapitant. The product was intended to prevent chemotherapy-induced nausea and vomiting. Although supportive care was not the same as direct tumor treatment, the approval provided Tesaro with a marketed medicine and demonstrated its ability to complete a regulatory development program. Tesaro's principal strategic focus subsequently shifted toward niraparib, a PARP inhibitor. The drug was reviewed through an FDA priority-review process, with a target action date set for June 2017. In March 2017, the FDA approved niraparib under the brand name Zejula for an ovarian-cancer indication. The approval established Tesaro as a notable specialist oncology company and made Zejula its most recognizable commercial asset. Tesaro continued to study niraparib in additional cancer settings, including breast and ovarian cancer applications beyond its initial approved use. The company also pursued other development programs. Rolapitant was studied in an intravenous formulation for chemotherapy-induced nausea and vomiting. Tesaro's pipeline included the investigational candidates TSR-042 and TSR-022. TSR-042 was later associated with dostarlimab, an immune-oncology medicine that became part of GSK's portfolio after the acquisition. In February 2023, the FDA approved dostarlimab-gxly, marketed by GSK as Jemperli, for a defined group of adults with mismatch repair-deficient recurrent or advanced endometrial cancer whose disease had progressed on or after a prior platinum-containing regimen and who were not candidates for curative surgery or radiation, as determined under the approved indication. Tesaro remained a relatively focused research organization. In 2016, it was reported to have 286 full-time employees, 59 of whom held a PhD or MD, indicating a substantial concentration of scientific and medical expertise for a company of its size. Its development-oriented structure also made it a potential acquisition target as larger pharmaceutical companies sought oncology assets with commercial and clinical potential. On May 31, 2017, reports indicated that Tesaro was exploring a sale. GlaxoSmithKline later announced on December 3, 2018, that it would acquire Tesaro for approximately $5.1 billion. The transaction closed on January 22, 2019. The acquisition transferred Tesaro's products, pipeline, and oncology capabilities to GSK and brought the independent Tesaro corporate brand to an end. Tesaro is consequently best understood as a former standalone American oncology biopharmaceutical company whose principal legacy is the development of Zejula and the oncology assets subsequently integrated into GSK.

• 2023

  Dostarlimab approved under GSK

  [1]Tesaroen.wikipedia.org

  The FDA approved dostarlimab-gxly, marketed as Jemperli by GSK, for a specified mismatch repair-deficient endometrial-cancer population.

• 2019

  Acquisition completed

  [1]Tesaroen.wikipedia.org

  GSK completed its acquisition of Tesaro on January 22, ending the company's independent operation.

• 2018

  GSK announces acquisition

  [1]Tesaroen.wikipedia.org

  GlaxoSmithKline announced an agreement to acquire Tesaro for approximately $5.1 billion.

• 2017

  Zejula approved for ovarian cancer

  [1]Tesaroen.wikipedia.org

  The FDA approved niraparib under the Zejula brand for an ovarian-cancer indication.

• 2017

  Sale exploration reported

  [1]Tesaroen.wikipedia.org

  Reports indicated that Tesaro was exploring a potential sale.

• 2016

  Workforce reaches 286 employees

  [1]Tesaroen.wikipedia.org

  Tesaro was reported to employ 286 full-time staff, including 59 people with a PhD or MD.

• 2015

  Varubi receives FDA approval

  [1]Tesaroen.wikipedia.org

  The FDA approved rolapitant, marketed by Tesaro as Varubi, for preventing chemotherapy-induced nausea and vomiting.

• 2010

  Tesaro founded

  [1]Tesaroen.wikipedia.org

  Tesaro was established as an American biopharmaceutical company focused on cancer medicines.

A research-focused oncology biopharmaceutical company whose commercial strategy centered on cancer therapeutics and supportive-care medicines.

• Chemotherapy supportive care · 2015

  Varubi

  Varubi is the brand name for rolapitant, a medicine developed to prevent chemotherapy-induced nausea and vomiting. It was Tesaro's first commercial product and received FDA approval in October 2015. The product addressed a supportive-care need associated with cancer treatment rather than functioning as a direct antitumor therapy.

• PARP inhibitor oncology medicine · 2017

  Zejula

  Zejula is the brand name for niraparib, an oral PARP inhibitor developed by Tesaro for oncology use. The FDA approved it in March 2017 for an ovarian-cancer indication after a priority-review process. Niraparib was also studied in additional cancer settings, including breast cancer. Zejula became Tesaro's principal commercial asset and was incorporated into GSK's oncology portfolio after the acquisition.

• Immune-oncology medicine · 2021

  Dostarlimab (Jemperli)

  Dostarlimab, associated with Tesaro development program TSR-042, is an oncology medicine later marketed by GSK as Jemperli. In February 2023, the FDA approved dostarlimab-gxly for a specified population of adults with mismatch repair-deficient recurrent or advanced endometrial cancer after prior platinum-containing treatment, subject to the approved indication and diagnostic criteria.

• Chemotherapy supportive care

  Intravenous rolapitant

  Tesaro investigated an intravenous formulation of rolapitant for the prevention of chemotherapy-induced nausea and vomiting. The formulation was described as being in Phase III clinical trials, representing an attempt to extend the company's supportive-care platform beyond the original Varubi product.

• Investigational oncology medicine

  TSR-022

  TSR-022 was one of Tesaro's named investigational oncology programs. The available reference material identifies the candidate as part of the company's development pipeline but does not provide sufficient detail here about its mechanism, clinical stage, indication, or subsequent disposition.

• 2018

  Agreement to sell Tesaro to GlaxoSmithKlineM&A

  Background

  Tesaro was a focused oncology company with commercial products and a developing cancer-medicine pipeline. Reports in 2017 had indicated that it was exploring a sale, and GSK subsequently announced an acquisition agreement.

  Action taken

  GlaxoSmithKline agreed to acquire Tesaro for approximately $5.1 billion.

  Aftermath

  The transaction closed on January 22, 2019. Tesaro ceased to operate as an independent company, while its products and pipeline were integrated into GSK's oncology business.

  Announced acquisition consideration. $5.1 billion (Announced December 3, 2018; completed January 22, 2019)

  Source

• 2023

  Dostarlimab receives FDA approval under GSK[1]Tesaroen.wikipedia.org

  Product launch · Regulation

  The FDA approved dostarlimab-gxly, marketed by GlaxoSmithKline as Jemperli, for a specified population of adults with mismatch repair-deficient recurrent or advanced endometrial cancer after prior platinum-containing treatment.

• 2019

  Tesaro acquisition completed[1]Tesaroen.wikipedia.org

  M&A · Leadership change

  The acquisition of Tesaro by GlaxoSmithKline was completed on January 22, 2019, ending Tesaro's independent corporate existence.

• 2018

  GlaxoSmithKline announces acquisition of Tesaro[1]Tesaroen.wikipedia.org

  M&A

  GlaxoSmithKline announced an agreement to acquire Tesaro for approximately $5.1 billion, bringing Tesaro's oncology portfolio into GSK.

• 2017

  FDA grants priority review to Tesaro's niraparib application[1]Tesaroen.wikipedia.org

  Regulation · Product launch

  Tesaro's application for niraparib received priority review, with a target FDA action date set for June 2017 during the regulatory process.

• 2017

  Zejula approved for ovarian cancer[1]Tesaroen.wikipedia.org

  Product launch · Regulation

  Tesaro received FDA approval for Zejula, the brand name for niraparib, for an ovarian-cancer indication.

• 2017

  Tesaro reportedly explores a sale[1]Tesaroen.wikipedia.org

  M&A · Other

  Reports stated that Tesaro was considering a sale, preceding the eventual acquisition announcement by GlaxoSmithKline.

• 2015

  Tesaro's Varubi receives FDA approval[1]Tesaroen.wikipedia.org

  Product launch · Regulation

  The FDA approved Varubi, Tesaro's rolapitant product, for the prevention of chemotherapy-induced nausea and vomiting. It became the company's first commercial product.

1. 1Tesaroen.wikipedia.org