GSK subsidiary TESARO starts legal action over Jemperli licence dispute

GSK

GSK plc (LON/NYSE:GSK) subsidiary, TESARO, Inc., has confirmed it has initiated litigation against AnaptysBio, Inc. in the Delaware Chancery Court. This action contends that recent conduct by AnaptysBio is in material breach of the existing license agreement with TESARO regarding the oncology treatment Jemperli (dostarlimab). The breach entitles TESARO to terminate the current license agreement, obtain a perpetual and irrevocable license to dostarlimab, and to reduce the royalties and milestone payments due by TESARO to AnaptysBio by 50%. 

TESARO has initiated this litigation following allegations made by AnaptysBio that TESARO has not fulfilled certain requirements of the license agreement entered in March 2014 and that AnaptysBio intends to revoke TESARO’s licence for dostarlimab. GSK and TESARO are firmly of the view that these allegations are entirely without merit.

Jemperli is currently approved in over 35 countries for use in certain endometrial cancers, the most common gynaecologic cancer in the United States. GSK and TESARO have reported significant growth for Jemperli driven by label expansions in endometrial cancer, including in the US and EU. A robust and ambitious clinical trial programme to evaluate the potential use of dostarlimab in additional cancers, including rectal, colon and head and neck, is ongoing.

Share on:

Latest Company News

GSK subsidiary TESARO starts legal action over Jemperli licence dispute

TESARO, part of GSK, has filed a case in the Delaware Chancery Court claiming AnaptysBio has breached its licence agreement for the cancer treatment Jemperli.

GSK Plc lifts 2025 guidance after strong Q3 sales and profit growth

GSK reported Q3 2025 sales of £8.5 billion, up 8% at constant exchange rates, driven by strong performances across Specialty Medicines, Vaccines and General Medicines.

GSK receives EMA Orphan Drug Designation for GSK5764227 in Pulmonary NEC

GSK has announced that its B7-H3-targeted antibody-drug conjugate, GSK5764227 (GSK'227), has been granted Orphan Drug Designation by the European Medicines Agency for treating pulmonary neuroendocrine carcinoma, including small-cell lung cancer.

GSK Plc gains FDA approval for Blenrep combination in multiple myeloma

GSK has received FDA approval for Blenrep (belantamab mafodotin-blmf) with bortezomib and dexamethasone to treat adults with relapsed or refractory multiple myeloma after at least two prior therapies.

GSK Plc names Luke Miels as CEO Designate, effective January 2026

GSK has announced the appointment of Luke Miels as CEO Designate, with full responsibilities and a Board position from 1 January 2026. Currently Chief Commercial Officer, Luke has been key in expanding GSK’s specialty medicines and vaccines portfolio, bringing senior experience from AstraZeneca, Roche and Sanofi-Aventis.

GSK’s Gepotidacin receives US FDA Priority Review for gonorrhoea treatment

GSK has announced that the US FDA has accepted for priority review a supplemental New Drug Application for gepotidacin as an oral treatment for uncomplicated urogenital gonorrhoea in patients aged 12 and over.

    Search

    Search