ESMO data on innovative Chinese cancer drugs: Similar efficacy in gastric cancer, with differences in tolerability and patient populations

How do the two gastric cancer drugs differ?

In gastric and gastroesophageal junction cancer patients with high CLDN18.2 expression who had received at least two prior lines of therapy, Innovent Biologics’ IBI343 achieved median overall survival of 10.2 months, compared with 6.9 months in the control group; rates of grade 3 or higher nausea and vomiting were 0.9% and 2.6%, respectively. Morgan Stanley therefore has a more favorable view of its gastrointestinal tolerability relative to CMG901.
In patients receiving third-line or later treatment, Keymed Biosciences’ CMG901 achieved median overall survival of 10.0 months, compared with 5.0 months in the control group. The hazard ratio for death among patients with target expression of 25%–74% was 0.63, leading the bank to believe that the addressable market may be broader than it had forecast; however, the hazard ratio for death in second-line patients who had received only one prior line of therapy was 0.88, indicating a smaller survival advantage over standard treatment.

Akeso’s ivo combined with chemotherapy for first-line treatment of biliary tract cancer produced an overall survival hazard ratio for death of 0.75; as a cross-trial reference, the hazard ratio in IMbrave151 was 0.97. Morgan Stanley believes this provides a clinically meaningful survival benefit as ivo expands beyond lung cancer.
The rates of serious treatment-emergent adverse events in the two groups were 43.4% and 43.7%, respectively, easing the bank’s concerns about toxicity in the phase two trial and strengthening the possibility that ivo plus chemotherapy could replace durvalumab plus chemotherapy. However, median overall survival in the control group was 12.1 months, between the 9.1 months in the TOPAZ-1 China cohort and 12.8 months in its global cohort.

For previously treated patients with HR-positive, HER2-negative breast cancer, DualityBio’s DB-1310 achieved median progression-free survival of 11.6 months at a dose of 5 mg/kg; in a cross-trial comparison, HER3-DXd achieved 9.2 months. Morgan Stanley believes this demonstrates efficacy potential, but rates of grade 3 or higher treatment-related adverse events were 47.1% and 50%, respectively, providing limited evidence of a tolerability advantage.
Two other drugs, SHR-A1811 and TQB2102, achieved median progression-free survival of 16.5 and 16.4 months, respectively, in patients with HR-positive, HER2-low breast cancer before chemotherapy; interstitial lung disease rates were 2.5% and 2.2% respectively. The bank believes this raises the bar for DualityBio’s DB-1303 data in the fourth quarter of 2026: even if it outperforms chemotherapy, adoption could be affected if its efficacy or treatment-limiting adverse event profile is not competitive.

For first-line treatment of extensive-stage small-cell lung cancer, Zai Lab’s zoci plus atezolizumab had not reached median progression-free survival among 15 patients at a median follow-up of 10 months, showing potential to exceed Morgan Stanley’s original expectation of 8 months; among 33 patients, the rate of grade 3 or higher adverse events was 21.2%, supporting exploration of a platinum- and etoposide-free regimen.
In HUTCHMED’s SAFFRON study, savo plus osimertinib for MET-driven, EGFR-mutant non-small-cell lung cancer after osimertinib treatment achieved median progression-free survival of 7.6 months, compared with 8.3 months for the cross-trial reference drug sac-TMT; overall survival hazard ratios for death were 0.68 and 0.69, respectively. Together with a serious treatment-emergent adverse event rate of 41%, the bank believes its differentiation from similar regimens is limited.