AstraZeneca is not alone in the race to bring a claudin 18.2 antibody-drug conjugate to stomach cancer patients. The AstraZeneca stomach cancer drug trial of sonesitatug vedotin (Sone-Ve) reported a 53% lower risk of death in third-line-and-later patients and 42% in the second-line-and-later population, while Takeda announced positive Phase 3 data for a rival conjugate two days earlier. This article looks at the competitive and regulatory picture. Both drugs are investigational.
Key takeaways: competition after the AstraZeneca stomach cancer drug trial
- Sone-Ve: third-line-and-later survival 10.0 versus 5.0 months (hazard ratio 0.47); second-line-and-later 10.6 versus 6.4 months (hazard ratio 0.58).
- Progression-free survival by blinded review was 4.2 versus 3.8 months (p=0.053), not statistically significant.
- AstraZeneca licensed Sone-Ve from KYM Biosciences in March 2023 and holds global exclusive rights.
- Sone-Ve has Orphan Drug Designation from the US FDA and the European Commission and Breakthrough Designation in China, per the company.
- Takeda’s rival conjugate was tested in Japan and China only.
The numbers in the AstraZeneca stomach cancer drug trial, corrected
The brief for this story described 532 patients with at least two prior treatments and gave the 53% figure for them. The company data show that 532 patients (267 versus 265) is the second-line-and-later population, with a 42% reduction in risk of death and 10.6 versus 6.4 months median survival. The 53% reduction and the 10 versus 5 months belong to the third-line-and-later subgroup of 355 patients (178 versus 177, our sum). Both sets are reported here against the correct group.
Sone-Ve versus the rival claudin 18.2 conjugate
Takeda’s arcotatug tavatecan (TAK-921) reported median survival of 10.2 versus 6.9 months and progression-free survival of 7.1 versus 3.1 months in patients in Japan and China after two to four prior regimens, as we reported in our article on that trial. The two programmes cannot be compared directly. They used different comparators, different populations, different lines of therapy and different regions, and the Takeda trial met its progression-free endpoint while Sone-Ve missed it at p=0.053. Sone-Ve’s trial was global, across 175 centres in 19 countries, which may matter for Western regulators.
AstraZeneca’s investigator said Sone-Ve is the first claudin 18.2-targeted conjugate to show a survival benefit in this setting. Given the Takeda announcement two days earlier, we treat that as the investigator’s characterisation and note that a rival has since reported survival data in a different population.
The regulatory position after the AstraZeneca stomach cancer drug trial
AstraZeneca says it will share the data with global regulators; it has not given filing dates. The Orphan Drug designations in the US and Europe and the Breakthrough designation in China for second-line gastric cancer are existing regulatory advantages. The registry entry for the trial is at ClinicalTrials.gov. A missed progression-free survival endpoint is a point regulators may raise, and the company’s case will rest on the survival results.
The patient pool for the AstraZeneca stomach cancer drug trial
According to AstraZeneca, about 60% of gastric and junction cancers express claudin 18.2 in at least 25% of tumour cells, and roughly 183,500 patients a year across the US, EU, China and Japan receive second-line-and-later treatment for advanced or metastatic claudin 18.2-positive, non-HER2-positive disease. Median survival with second-line-and-later treatment is 5 to 9 months, the company says. These are company estimates and not independently verified.
Timeline of the AstraZeneca stomach cancer drug trial
- March 2023: licence agreement with KYM Biosciences.
- 31 May 2026: data cutoff.
- 23 October 2026: Takeda announces its rival trial results.
- 25 October 2026: AstraZeneca announces and presents at ESMO (LBA7).
Antibody-drug conjugate market data and the AstraZeneca stomach cancer drug trial
Acumen Research and Consulting’s report Antibody Drug Conjugate Market Size, Share, Analysis, Trends and Forecast 2024 to 2032 values the global antibody-drug conjugate market at USD 10.3 billion in 2023 and projects USD 30.9 billion by 2032, a CAGR of 13.2% from 2024 to 2032. It describes HER2 as the long-standing leading target and says breast cancer held 48% of the 2023 market, so claudin 18.2 and gastric cancer would be a new segment. The page’s updated date is inconsistent with its forecast period, so treat the figures as estimates. More in our pharmaceuticals coverage.
General background: how big pharma builds ADC franchises
Large drugmakers have been licensing or acquiring antibody-drug conjugates because they combine a targeted antibody with potent chemotherapy. AstraZeneca’s Sone-Ve came through a licence from KYM Biosciences, and the company’s head of oncology research said it has the potential to reshape gastric cancer treatment, which is the company’s view.
Our analysis of the AstraZeneca stomach cancer drug trial: commercial implications
In our assessment, the AstraZeneca stomach cancer drug trial gives AstraZeneca a credible late-stage asset with a global dataset, and the survival result in a patient population with few options is clinically significant. The missed progression endpoint and the rival’s earlier announcement lessen the sense of exclusivity. The commercial outcome will depend on approvals, labels, testing uptake and any head-to-head perceptions that clinicians form. We make no sales forecasts and give no investment advice.
What is not disclosed about the AstraZeneca stomach cancer drug trial
- Filing dates and review timelines.
- Financial terms of the KYM Biosciences licence.
- Response rates and specific adverse events.
- Pricing.
Risks and caveats of the AstraZeneca stomach cancer drug trial
Both drugs are investigational. The data are from company announcements as reported, and the Sone-Ve progression-free survival endpoint was not met. Company patient-pool estimates are unverified. Acumen figures are broad estimates. This article is news reporting and not investment or medical advice.
What to watch next after the AstraZeneca stomach cancer drug trial
- Regulatory filings in the US, Europe and China.
- Publication of full data, including side effects.
- Takeda’s own filing plans.
- Trials of both drugs in earlier lines.
FAQ
How does the AstraZeneca stomach cancer drug trial compare with Takeda’s?
They differ in populations, comparators and regions, so they cannot be compared directly.
Who owns Sone-Ve?
AstraZeneca has global exclusive rights under a March 2023 licence from KYM Biosciences.
Is Sone-Ve approved?
No. It is investigational.
How we reported this: we relied on the AstraZeneca announcement and ESMO presentation as reported, the trial registry and the Acumen Research and Consulting report cited above, and attributed every claim. Last updated 26 October 2026. This is news reporting and not advice.
