ASCO 2025 | MATTERHORN: EFS outcomes of durvalumab plus FLOT in GC/GEJC

MATTERHORN is a large phase three global study of recurrent patients from all over the world, including Asia. And the purpose of the study was to test the hypothesis that the combination of immunotherapy plus chemotherapy will help suppress micrometastases and treat patients with early-stage gastric and esophageal adenocarcinoma. We enrolled close to 940 patients in one-to-one randomization to receive FLOT plus durvalumab versus placebo and durvalumab. Patients were enrolled irrespective of PD-L1 status, and we allowed patients with T2 or T4A disease, and patients were stratified by PD-L1 using IHC score and presence of lymph node metastasis clinically, and also by location geographically, Asia versus non-Asia. Everyone received four doses of FLOT before surgery and two doses of durvalumab before surgery, and then four doses of FLOT after surgery with durvalumab, and then followed by 10 more doses of durvalumab. So overall, one year of therapy. The primary endpoint was event-free survival, and we already presented data from the pathologic complete response, because that was a key secondary endpoint. And another data that will be presented at ASCO is a secondary endpoint of overall survival. So what we demonstrated is that, as we’ve shown before, pathologic complete response is improved in this cohort. And what we’re now showing at ASCO is that this improvement in pathologic response translates to also event-free survival benefit. What we will show you is the data from the event-free survival, which is a primary endpoint. And as you know, from the press release and from the fact that it’s presented at ASCO Plenary, is that it’s a strongly positive study.