Akeso, Inc. (HKEX: 9926) has enrolled the first patient in COMPASSION-37, a global Phase 3 trial testing its cancer drug cadonilimab against today’s first-line standard of care for advanced stomach cancer. The Hong Kong-listed drugmaker announced the milestone in a press release dated Sunday, September 27, 2026.

There are no results yet. The trial just opened. What makes it worth watching is the target. Akeso is going after the patients who get the least out of current immunotherapy, and its comparator arm includes nivolumab, sold by Bristol Myers Squibb (NYSE: BMY) as Opdivo. The release never names Bristol Myers.

What COMPASSION-37 Will Test

The study (AK104-311; ClinicalTrials.gov NCT07700979) enrolls previously untreated adults with HER2-negative gastric or gastroesophageal junction (G/GEJ) adenocarcinoma that can’t be removed surgically or has spread. HER2-negative means the tumor lacks the HER2 protein some targeted drugs attack. The GEJ is where the esophagus meets the stomach.

Patients get cadonilimab plus chemotherapy, or chemotherapy with or without nivolumab. That last phrase matters. Akeso bills the study as head-to-head against nivolumab, but by the release’s own description the control arm also allows chemotherapy alone. How that choice gets made isn’t explained.

Other gaps: no enrollment target, no primary endpoint, no country count, no timeline for data. The FDA cleared the trial to begin in December 2025, according to an earlier Akeso release.

The investigator roster carries weight. Dr. Yelena Janjigian of Memorial Sloan Kettering Cancer Center, a global principal investigator here, led CheckMate 649, the Bristol Myers trial that made nivolumab plus chemotherapy a first-line standard. Professor Markus Möhler of Johannes Gutenberg University Mainz and Professors Jiafu Ji and Lin Shen of Peking University Cancer Hospital round out the group.

Two Brakes, One Molecule

Immune checkpoints work like brakes on T cells, the immune cells that kill tumors. PD-1 and CTLA-4 are two separate brakes. Nivolumab releases PD-1 only. Cadonilimab is a bispecific antibody, a single engineered molecule that binds both targets at once. Akeso describes it as first-in-class.

Hitting both brakes isn’t new in this disease. CheckMate 649 also tested nivolumab plus Bristol Myers’ CTLA-4 drug ipilimumab, given without chemotherapy. That arm failed to significantly improve overall survival over chemotherapy in patients with higher PD-L1 levels (hazard ratio 0.89).

Cadonilimab takes a different route: both targets in one molecule, paired with chemotherapy. Whether that holds up outside China is what COMPASSION-37 has to show.

The PD-L1 Gap

PD-L1 is a protein measured on a tumor biopsy and reported as a combined positive score, or CPS. Higher scores tend to mean more benefit from PD-1 drugs. At the low end, the benefit gets thin.

Regulators noticed. In June 2025, the FDA narrowed the gastric cancer labels for Opdivo and Merck’s (NYSE: MRK) Keytruda to patients with a CPS of 1 or higher, after an advisory committee voted against the broader use in September 2024. In a CheckMate 649 subgroup the agency highlighted, PD-L1-low patients lived a median 13.1 months on nivolumab plus chemotherapy versus 12.5 months on chemotherapy alone.

Akeso’s release adds that NCCN and ESMO treatment guidelines preferentially recommend nivolumab-based regimens at CPS 5 or above. That leaves a big group of patients with weaker options. Akeso wants cadonilimab to be the answer for them.

What the China Trial Actually Showed

The case rests on COMPASSION-15, a 610-patient, double-blind, placebo-controlled Phase 3 run in China. The release says cadonilimab plus chemotherapy reduced the risk of death regardless of PD-L1 status. It gives no numbers.

Here they are. In the final analysis presented at ESMO 2025, median overall survival was 13.9 months with cadonilimab versus 11.1 months with placebo plus chemotherapy (HR 0.61; 95% CI, 0.51-0.73). In patients with a CPS of 5 or more, it was 16.8 versus 10.8 months (HR 0.49). Below CPS 5, it was 13.2 versus 11.3 months (HR 0.76; 95% CI, 0.59-0.99).

So the low-PD-L1 benefit exists, but it’s smaller, and the upper end of its confidence interval sits just under 1.0. Professor Ji, one of the trial’s own investigators, calls it a “favorable survival trend” in the release.

Side effects ran heavier, too. Grade 3 or worse treatment-related adverse events hit 66.9% of cadonilimab patients versus 53.6% on placebo. Treatment-related discontinuations were 23.9% versus 6.6%.

One more caution. COMPASSION-15 compared cadonilimab with placebo, not nivolumab, and enrolled only patients in China. Janjigian herself has warned that its results are hard to line up against CheckMate 649, given differences in chemotherapy duration and follow-on treatment. Cross-trial comparisons like that are suggestive, not proof. COMPASSION-37 will be the first test against an active immunotherapy comparator.

A “First” That Doesn’t Hold Up

The release calls cadonilimab the first approved bispecific antibody for cancer treatment. As written, that’s wrong. Amgen’s (Nasdaq: AMGN) blinatumomab, sold as Blincyto, won FDA approval in leukemia in December 2014, and catumaxomab was approved in Europe in 2009. Cadonilimab’s first approval came in China in June 2022. Akeso’s own corporate profile uses narrower wording: the first dual immune checkpoint bispecific approved for tumors.

A name check, while we’re here. Cadonilimab is not ivonescimab, Akeso’s PD-1/VEGF bispecific licensed to Summit Therapeutics (Nasdaq: SMMT) for the U.S., Europe, Canada and Japan. The Summit deal covers ivonescimab only. Neither this release nor Akeso’s December 2025 announcement names an outside commercial partner for cadonilimab.

Where Things Stand

Cadonilimab is approved only in China: for previously treated cervical cancer (June 2022), first-line gastric/GEJ cancer (September 2024) and first-line cervical cancer (May 2025). It has no FDA or European approval for any use. A separate U.S. Phase 2 study (NCT07631000), also led by Janjigian, is testing it around surgery in earlier-stage, operable gastric cancer.

Akeso hasn’t said when COMPASSION-37 might read out, or whether it plans a U.S. filing. For now this is an enrollment milestone. The data that matter are still to come.

Sources

• Akeso: Akeso Announces First Patient Enrolled in Global Phase III Trial of Cadonilimab Versus Nivolumab in First-Line Gastric Cancer, PRNewswire, September 27, 2026. Primary source release.
• Akeso: Cadonilimab (PD-1/CTLA-4) Receives FDA Clearance for Global Phase III First-Line Gastric Cancer Trial Versus Nivolumab, December 11, 2025, cited for the FDA clearance to begin COMPASSION-37.
• ClinicalTrials.gov: NCT07700979 (AK104-311), cited for the COMPASSION-37 registry number, which the release did not give.
• OncLive: Cadonilimab Plus Chemo Retains Clinically Meaningful Survival Advantage in Frontline Gastric/GEJ Adenocarcinoma, cited for final COMPASSION-15 overall survival, PD-L1 subgroup and safety figures (ESMO 2025), none of which appeared in the release.
• Nature Medicine: First-line cadonilimab plus chemotherapy in HER2-negative advanced gastric or gastroesophageal junction adenocarcinoma, cited for the peer-reviewed COMPASSION-15 trial design.
• MDedge: Combo Therapy Prolongs Survival in Gastric Cancer Patients, Regardless of PD-L1 Expression, cited for Dr. Janjigian’s caution on comparing COMPASSION-15 with CheckMate 649.
• The ASCO Post: CheckMate 649 Long-Term Data Support Nivolumab Plus Chemotherapy but Not Nivolumab Plus Ipilimumab in Gastric Cancer, cited for the failed nivolumab-plus-ipilimumab arm of CheckMate 649.
• Avalere Health: FDA Restrictions on PD-L1-Negative Gastric Cancer Treatments, cited for the June 2025 Opdivo and Keytruda label changes and the September 2024 advisory committee vote.
• Oncology News Central: FDA Limits Pembrolizumab and Nivolumab in PD-L1-Low Stomach Cancers, cited for the CheckMate 649 PD-L1-low subgroup survival figures highlighted by the FDA.
• Nature Reviews Drug Discovery: FDA Approves First Bispecific, cited for blinatumomab’s December 2014 FDA approval, used to check the release’s “first approved bispecific” claim.
• Clinical and Translational Science (PMC): Biologic Drug Combinations and Bispecifics, cited for catumaxomab’s 2009 approval as the first bispecific antibody.
• Akeso: Corporate Profile, cited for Akeso’s own narrower “first dual immune checkpoint bispecific” framing.
• Summit Therapeutics Form 10-Q (SEC EDGAR), cited to distinguish Summit’s ivonescimab license from cadonilimab.

Editorial Disclosure

This article reports on a press release issued by Akeso, Inc. on September 27, 2026, announcing enrollment of the first patient in COMPASSION-37, a global Phase 3 trial of cadonilimab. Securities and corporate structures discussed: Akeso, Inc. (Hong Kong Stock Exchange: 9926), Bristol Myers Squibb Company (NYSE: BMY), Merck & Co., Inc. (NYSE: MRK), Amgen Inc. (Nasdaq: AMGN), and Summit Therapeutics Inc. (Nasdaq: SMMT). BioTech Stocks Daily has not received, nor will it accept, any compensation, direct or indirect, from Akeso, Bristol Myers Squibb, Merck, Amgen, Summit Therapeutics, or any other corporate or third-party sponsor for the preparation or publication of this coverage. No staff member, principal, or affiliate of BioTech Stocks Daily holds a position, option, or financial interest in any of the securities mentioned as of the date of publication. COMPASSION-15 results, CheckMate 649 data, FDA labeling actions, and the regulatory history of bispecific antibodies were drawn from the independent sources cited above, since the original release did not address them. Statements regarding trial enrollment, future data readouts, potential regulatory submissions outside China, the ability of cadonilimab to benefit patients with low PD-L1 expression, and competitive positioning against approved immunotherapies are forward-looking statements. They involve substantial risks, regulatory uncertainties, and scientific variables; actual clinical outcomes, development timelines, and commercial approvals may differ materially. Clinical-stage biotechnology investments carry an extreme degree of financial risk. Drug development is subject to high rates of clinical failure, regulatory rejection, and market competition, which can result in the total loss of invested capital. This article is published strictly for independent news reporting, market context, and educational purposes only. It does not constitute an investment recommendation, endorsement, or professional financial, legal, or tax advice. Furthermore, this content is not medical advice; patients and healthcare providers should consult appropriate clinical professionals for medical guidance.

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