AstraZeneca to invest $2.0 billion in Summit Therapeutics via preferred stock
The purchase agreement, signed September 28, 2026, is expected to close within five business days, subject to customary conditions
Published
AstraZeneca Holdings B.V. will buy about 108,955 newly designated shares of Class A Convertible Preferred Stock in Summit Therapeutics for $2.0 billion, at $18,356.14 a share. Each preferred share converts into common stock at a ratio of 1 to 1,000, putting the conversion price at $18.36 a common share.
Alongside the equity purchase, a Summit subsidiary has signed a separate clinical trial collaboration with AstraZeneca to study sonesitatug vedotin in combination with ivonescimab. The two companies have also signed a non-binding memorandum of understanding to explore pairing ivonescimab with other AstraZeneca cancer medicines.
The deal marks a shift from AstraZeneca's recent oncology partnerships, which have mostly involved sharing clinical data, such as the DeLLphi-305 readout with Amgen on September 8, toward a direct capital stake in a partner company. The conversion price sits well above where Summit shares have recently traded, a sign that AstraZeneca is pricing in ivonescimab's long-term value rather than striking an opportunistic or distressed deal.
Taken together, the equity investment, the formal trial collaboration and the broader memorandum point to an alignment stretching over several years rather than a single transaction. For Summit, the deal brings the backing of a major pharmaceutical balance sheet to its lead drug and eases pressure on its financing. It is a clearly favourable outcome for Summit and adds another piece to AstraZeneca's expansion in oncology.