The all-stock deal gives Summit Therapeutics enough money to see through Phase 3 trials for the PD-1/VEGF bispecific ivonescimab—but keeps the asset fully in-house without giving up licensing rights.
AstraZeneca is making a $2 billion equity investment into Summit Therapeutics, an agreement that could help clear what Stifel called the biotech’s “financing overhang” and fund development of the PD-1/VEGF bispecific antibody ivonescimab.
Under the terms of the equity investment, Summit’s shares are “directly sold to AstraZeneca,” Stifel explained in a Tuesday morning note, meaning the full $2 billion value will go to the biotech. “There is no license, nothing else sold but stock, so SMMT keeps full ivonescimab economics in its territories,” the firm said.
AstraZeneca’s moves creates “a meaningful strategic position without acquiring the company or licensing ivonescimab outright at this stage,” BMO Capital Markets wrote.
Summit’s shares climbed more than 16% to $17.96 as the markets opened Tuesday.
AstraZeneca has agreed to purchase around 109,000 shares of Summit’s preferred stock, each of which is convertible to 1,000 shares of the biotech’s common stock—an arrangement that will put roughly 12% of the biotech’s common shares under AstraZeneca’s ownership. The investment represents a common stock price of $18.36 per Summit share, which corresponds to a 10% premium on the biotech’s five-day weighted average price from last week, Stifel wrote on Monday evening.
The partners expect to close the agreement within a week, subject to certain regulatory clearances, according to a Monday afternoon release.
The transaction, which brings Summit’s cash to an estimated $2.5 billion, should give the biotech the money to fund all ongoing global Phase 3 readouts, Stifel said. The biotech in July said that it had just over $690 million in cash, equivalents and short-term investments left, limiting its runway to under a year.
“We don’t have formal guidance on this yet,” Stifel wrote, but with “some back-of-envelope math,” the analysts figure the cash should carry the biotech between two to four years from the end of this year’s third quarter.
Aside from the equity investment, AstraZeneca and Summit have entered into a clinical collaboration to combine the pharma’s anti-CLDN18.2 antibody-drug conjugate sonesitatug vedotin (sone-ve) with ivonescimab.
The partners are planning to study sone-ve plus ivonescimab in gastrointestinal cancers, with trials set to start “imminently,” according to the Monday announcement. AstraZeneca will take the lead as sponsor, with development costs shared between the partners. Development and commercial rights over the individual assets will remain with their respective owners. The agreement also allows the partners to potentially test ivonescimab with AstraZeneca’s other cancer medicines, according to the Monday release.
For AstraZeneca, the timing of the investment is “interesting,” Stifel added, noting that Summit and Chinese partner Akeso will present more detailed data from the Phase 3 HARMONi-GI1 trial at the upcoming European Society of Medical Oncology congress next month. A topline readout last month showed that ivonescimab plus chemotherapy outperformed AstraZeneca’s PD-L1 therapy durvalumab with chemotherapy as a first-line intervention for patients with advanced biliary tract cancer.
“More broadly, the transaction is another clear signal that the PD-1/VEGF field is heating up,” BMO Capital Markets analysts wrote to investors Tuesday morning. “AstraZeneca is committing $2 billion before gaining direct commercial rights, underscoring the strategic value large pharma now places on securing exposure to the class and shaping future combination strategies.”
Summit and Akeso are primarily studying ivonescimab for non-small cell lung cancer (NSCLC). China’s medicines regulator in May 2024 first approved the antibody in combination with chemotherapy for the second-line treatment of patients with NSCLC carrying EGFR mutations.
Another approval came in China last month, pushing the regimen up to first-line NSCLC. However, the Chinese regulator posted data with that approval that pointed to declining progression-free survival benefits associated with ivonescimab.
Summit is currently working on FDA approval for ivonescimab, but it may be an uphill battle. An interim readout from the Phase 3 HARMONi-3 study in May suggested that the antibody missed an early survival threshold. May 2025 delivered a similar disappointment, with the late-stage HARMONi study finding no significant benefit on overall survival, one of the study’s primary endpoints. A readout from HARMONi in July, however, showed that ivonescimab’s survival benefit appears to be comparable between Western and Chinese patients, potentially helping Summit and Akeso sharpen their case for a U.S. approval.
Summit filed a biologics license application (BLA) for the drug earlier this year, with a decision expected on or before Nov. 14.
