As Summit Therapeutics’ Chinese partner prepares to reveal data for a key trial at ASCO, analysts consider the impact on rivals Merck, Bristol Myers Squibb and BioNTech.
Summit Therapeutics’ Chinese partner Akeso will present overall survival data for the pair’s PD-1/VEGF asset ivonescimab at the American Society of Clinical Oncology meeting this weekend. The long-awaited readout could help experts understand how the emerging modality will compete with anti-PD-(L)1 agents like Merck’s Keytruda in lung cancer.
BMO Capital Markets expects the plenary session—scheduled for Sunday—to steal the show, according to a Friday morning note. The readout is expected to have a ripple effect across the oncology space, as many rivals like Merck, Bristol Myers Squibb and BioNTech have similar assets in the clinic.
“Put simply, we will start to better understand how PD-(L)1xVEGF bispecifics stack up against anti-PD-(L)1 agents,” the analysts wrote.
Akeso already presented progression-free survival (PFS) data from the Phase 3 HARMONi-6 study, which features patients with first-line advanced squamous non-small cell lung cancer (NSCLC). The ivonescimab drug combo showed 11.14 months of PFS compared to 6.9 months in the comparator group. The ASCO update will provide a look at overall survival, comparing ivonescimab to BeOne’s Tevimbra and chemotherapy.
BMO is expecting HARMONi-6 to show statistically significant improved survival, with a hazard ratio—a marker of the risk of death during the trial—of around 0.65 to 0.72 in the firm’s bull case. A lower hazard ratio means better survival.
“While HARMONi-6 won’t dethrone King Keytruda, positive data could start to change the narrative around IO [immuno-oncology] in NSCLC,” BMO wrote.
The next big thing
PD-(L)1/VEGF therapies target two key cancer pathways, not only blocking checkpoint inhibition like classic IO agents such as Keytruda but also preventing the tumor from forming new blood vessels. Myriad companies have picked up these assets as a new wave of IO takes hold after the stunning success of Keytruda.
If the readout is as strong as BMO expects, Merck’s shares will likely decline. BMO explained that, while the company has a PD-L1/VEGF asset called MK-2010 in development, the oncology titan has focused much of its near-term strategy instead on the TROP2-directed antibody-drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT).
Merck has already reported early data in first-line NSCLC for MK-2010 but did so without much fanfare. The company also has not revealed Phase 3 plans, which leads BMO to believe the asset is not a high priority.
“Did Merck prioritize the right asset in looking for what’s next in solid tumor oncology?” the BMO team wondered. Merck will present data for sac-TMT at ASCO, which could help level out any share impact from the ivonescimab data, the firm added.
ADCs are a hot space in oncology as well, with Merck plunking down $4 billion upfront to partner with Daiichi Sankyo in 2023. Sac-TMT was brought into the fold through a massive licensing deal with China’s Kelun-Biotech worth up to $9.3 billion.
Also in the hunt for PD-L1/VEGF glory is BioNTech, which partnered with Bristol Myers Squibb in June 2025 in a deal valued at up to $11 billion to work on pumitamig. A strong readout for Akeso and Summit could drive the German biotech’s shares up, according to BMO, which dubbed BMS and BioNTech a “power couple.”
“We believe BioNTech’s decision to partner with Bristol on development across oncology indications was a savvy business move, as they can now leverage Bristol’s global commercialization expertise while balancing developmental expenses and risks,” the firm wrote.
BMS also made a smart move, according to BMO, with a successful result for pumitamig providing clarity as the New Jersey–based company faces critical loss of exclusivity on key products like the Pfizer-partnered blood thinner Eliquis in the coming years.
Data from the Phase 2/3 ROSETTA Lung-02 of pumitamig in first-line NSCLC will be showcased at ASCO on Saturday. BMO also expects to learn more about the therapy’s initial response in squamous and nonsquamous disease subtypes.
Summit is further ahead than BMS and BioNTech, having already submitted an FDA application for ivonescimab as a later line of treatment in NSCLC. The HARMONi-6 data could support a move to first-line therapy, representing an even greater NSCLC population segment.
Pfizer is also developing a PD-L1/VEGF bispecific called PFE-08634404, with data to come at ASCO. And AbbVie recently signed a deal with China’s RemeGen for a similar drug, dubbed ABBV-1480, with $650 million paid upfront plus up to $4.95 billion in milestones—underscoring the big money on the line for this emerging modality.
Lung cancer may just be the beginning for PD-L1/VEGFs, analysts and experts have predicted. BMO sees promise in colorectal cancer, where even Keytruda has struggled to gain traction in the clinic. With the VEGF interaction preventing the formation of new blood vessels that feed tumors, bispecifics could at the same time help more tumor-attacking immune cells enter to fight the cancer. VEGF is also known to drive PD-L1 resistance, so inhibiting the pathway could boost the efficacy of the treatment’s other side as well, BMO explained.
Whoever wins the PD-L1/VEGF race, the oncology world is about to confront a new paradigm: Keytruda will lose patent exclusivity in 2029, BMO noted. So newer agents will need to show strong efficacy to unseat a cheaper generic version of the drug.
“Bispecifics need to demonstrate significantly differentiated efficacy to succeed in a post-Keytruda market, as incrementally improved efficacy could limit uptake,” BMO wrote.
All eyes will be on ASCO this weekend to see if that differentiation will emerge for Akeso and Summit or any of their PD-L1/VEGF competitors.
