Jazz Pharmaceuticals has announced a definitive agreement to acquire Chimerix, a US-based biotech firm, for approximately $935m in cash.
The deal, disclosed on Wednesday 5 March, will see Jazz pay $8.55 per share, representing a 72.4% premium to Chimerix’s 4 March closing price of $4.96. Both companies have approved the transaction, which is expected to close in Q2 2025. Chimerix’s shares were up 69% when the markets opened, approaching Jazz’s offer price.
The acquisition will give Jazz access to Chimerix’s lead investigational candidate dordaviprone, which is under review by the US Food and Drug Administration (FDA) for the treatment of recurrent H3 K27M-mutant diffuse glioma, a rare and aggressive brain tumour that primarily affects children and young adults. Currently, there are no FDA-approved therapies for this condition, and patients typically face a poor prognosis with limited treatment options beyond radiotherapy and palliative care.
The FDA is expected to issue a decision on dordaviprone by 18 August 2025. The drug is also being evaluated in the Phase III ACTION trial (NCT05580562), which has enrolled newly diagnosed patients with non-recurrent H3 K27M-mutant diffuse glioma following radiation treatment. If the trial proves successful, dordaviprone could be used as a front-line therapy.
Dordaviprone is designed to activate stress responses in cancer cells, pushing them into apoptosis by acting on the mitochondrial protease ClpP and dopamine receptor D2 (DRD2). According to GlobalData’s Pharma Intelligence Center, dordaviprone is forecast to generate up to $385m in global sales by 2030.
GlobalData is the parent company of Pharmaceutical Technology.
The acquisition of Chimerix follows Jazz’s November 2024 FDA approval of Ziihera (zanidatamab), a HER2-directed bispecific antibody for biliary tract cancer. Jazz has also been developing Ziihera for HER2-positive breast and gastric cancers. In 2021, the company acquired GW Pharmaceuticals for $7.2bn, gaining the seizure medication Epidiolex (cannabidiol). In February 2024, it licensed a KRAS inhibitor programme from UK-based Redx Pharma in a deal worth up to $880m.
Chimerix originally acquired dordaviprone in 2021 through its purchase of Oncoceutics, in a deal that could be worth over $400m if all milestones are met. If ONC201 receives FDA approval, Chimerix could be eligible for a priority review voucher, a programme designed to incentivise drug development for rare paediatric diseases.
In the announcement accompanying the deal, Jazz stated that dordaviprone has patent protection extending to 2037. “If approved, dordaviprone has the potential to rapidly become a standard of care for a rare oncology disease and also contribute durable revenue beginning in the near-term,” added Jazz’s CEO Bruce Cozadd.
The acquisition follows a broader trend of significant M&A activity in the pharmaceutical sector since the start of 2025, with major deals from companies such as Johnson & Johnson, Eli Lilly, and GSK, each valued at over $1bn.
