With companies including AstraZeneca, Pfizer and Revolution Medicines clamoring to get in on Summit Therapeutics’ Akeso-partnered PD-1xVEGF antibody, one analyst calls the asset “the next major backbone” of cancer treatment.
Summit Therapeutics’ Akeso-partnered PD-1xVEGF bispecific antibody ivonescimab finds itself at the center of a cancer collaboration craze, with some of biopharma’s biggest names lining up for a chance to hook their respective assets onto what could possibly be oncology’s next big thing.
After besting Merck’s mega-blockbuster Keytruda in a China-based head-to-head Phase 3 study in non-small cell lung cancer (NSCLC) in September 2024, “ivonescimab pretty much set the world on fire,” Graig Suvannavejh, managing director and senior biotech and biopharma analyst at Mizuho Securities, told BioSpace in an email interview.
Keytruda inhibits the PD-1 pathway, which prevents cancer cells from evading and weakening the immune system’s anticancer response. Adding a VEGF mechanism on top of this additionally stops the formation of new blood vessels, starving the tumor. The PD-1xVEGF market could exceed $30 billion by 2032, according to Vision Lifesciences.
A telling readout from a global Phase 3 trial testing ivonescimab versus Keytruda as a frontline treatment option for NSCLC is set to drop “any day now,” Suvannavejh noted.
“If ivonescimab ultimately lives up to its billing of being better than Keytruda,” he said, the asset “theoretically could stand to become the next major backbone of treatment in cancer in the future.”
This notion is not lost on other drugmakers. Many leading biopharma companies have entered into clinical trial collaborations with Summit, hoping to package their products into combo regimens with ivonescimab.
“Organizations have increasingly approached us about partnering on clinical studies evaluating ivonescimab in combination regimens,” Dave Gancarz, chief business and strategy officer at Summit, told BioSpace in an email. Other companies with active clinical trial collaborations to pair their drugs with ivonescimab include AstraZeneca and Revolution Medicines. Gancarz said that this activity reflects broad scientific interest in the drug’s potential as an immunotherapy backbone across multiple tumor types and treatment settings.
AstraZeneca in particular has bought into Summit and ivonescimab. Not only has the British-Swedish heavyweight struck two separate clinical trial collaborations with the biotech, it recently gave Summit a $2 billion equity investment.
“The completed equity investment gives AstraZeneca direct economic participation in Summit’s future value creation across the broader ivonescimab opportunity, not only potential combinations with AstraZeneca medicines,” a company spokesperson told BioSpace in an email.
Pharma powerhouses and rising stars
It’s too early to say how big ivonescimab could become in the cancer space, Dara Azar, associate vice president of Biotech Equity Research at Stifel, told BioSpace in an email interview, “but it looks like AstraZeneca didn’t want to wait.”
Most recently, the pharma and partner Daiichi Sankyo inked a clinical trial collaboration to evaluate their TROP2-targeting antibody-drug conjugate (ADC) Datroway alongside ivonescimab in multiple tumor types. The collaboration will kick off with a late-stage study in first-line triple-negative breast cancer, though the companies haven’t specified a start date.
And just days before the Datroway deal, AstraZeneca announced a separate clinical trial collaboration with Summit that will combine ivonescimab with its anti-CLDN18.2 ADC sonesitatug vedotin (sone-ve). The agreement focuses on gastrointestinal cancers, with studies set to begin “imminently,” the pharma said.
Part of why AstraZeneca has pushed so hard with ivonescimab combo deals, Azar said, could be because many of its peers were already in the PD-1xVEGF race. Merck in November 2024 paid $588 million upfront and put an additional $2.7 billion on the line to exclusively license LaNova Medicines’ PD-1xVEGF bispecific LM-299. Pfizer, meanwhile, has also started building out its PD-1xVEGF pipeline, betting up to $6 billion in May 2025 to advance 3SBio’s SSGJ-707, now named PF-08634404 and in multiple clinical trials across urothelial carcinoma, NSCLC and renal cell carcinoma, among other cancer types.
Already having a PD-1xVEGF doesn’t mean these pharmas aren’t also considering an ivonescimab combo. Three months before inking the 3SBio pact, Pfizer entered into a clinical trial collaboration with Summit to test ivonescimab with “several” of its ADCs for various solid tumor indications. Pfizer is putting forward its vedotin ADCs, most of which it obtained in the $43 billion acquisition of Seagen in 2023. This class includes its FDA-approved Padcev, indicated for urothelial cancer, and sigvotatug vedotin, in Phase 3 development for NSCLC.
Ivonescimab’s appeal also extends beyond Big Pharma. In June 2025, Revolution Medicines—which recently secured FDA approval for its pancreatic cancer drug Rasonque—offered its array of RAS(ON) inhibitors, including Rasonque, as potential combination partners for ivonescimab. This clinical trial tie-up also includes the investigational G12D-selective and G12C-selective inhibitors zoldonrasib and elironrasib, respectively.
Even more such deals are on the way, Gancarz told BioSpace, though he declined to provide specific details, as these potential partnerships are still under discussion.
The next Keytruda?
While the influx of interest in ivonescimab bodes well for the up-and-comer, the therapy still has a long way to go to dethrone Keytruda.
“Keytruda is the most successful cancer drug of all time, with the drug now approved to treat over 40 cancers, and global revenue topping $31bn in 2025,” Mizuho’s Suvannavejh told BioSpace.
But ivonescimab earned its “Keytruda killer” nickname for a reason. While an overall survival miss in a global Phase 3 study in May 2025 dampened sentiment surrounding the bispecific’s competitive value, many still believe that ivonescimab will ultimately be a more effective treatment than Merck’s.
“Investors expect this drug to ultimately be proven as the better checkpoint inhibitor,” Stifel’s Azar told BioSpace.
Ivonescimab is currently under FDA review as a second-line treatment for patients with advanced non-squamous NSCLC, with a decision expected Nov. 14. Looking at ivonescimab’s body of data so far, Azar doesn’t expect the drug to run into any major regulatory issues.
AstraZeneca is a bit more reserved when it comes to ivonescimab. “It is important to be balanced about the evidence,” the spokesperson said. “Much of the positive data to date comes from China-only trials, and we recognize that single-region data have more limited relevance to populations outside China.”
Indeed, ivonescimab’s current application is backed by the Phase 3 HARMONi trial, which hinted at slight differences in the drug’s efficacy between Asian and Western patients. Summit did not provide statistical analyses for the survival benefit seen in HARMONi, however. The AstraZeneca spokesperson said ivonescimab will need to show that it can significantly improve overall survival in global patient populations to credibly support an approval bid outside of China.
More Western data should be coming soon. Summit is anticipating final progression-free survival (PFS) data from the Phase 3 multiregional HARMONi-3 study testing ivonescimab versus Keytruda as a frontline treatment option for NSCLC before the end of the year.
“All eyes are focused on the announcement of Phase 3 HARMONi-3 study data,” Suvannavejh said.
“If the data do pan out,” he continued, “then simply put, ivonescimab has the potential to replace Keytruda as the next major backbone of treatment in cancer—and in turn, to become the next best-selling oncology drug of all time.”
