Imfinzi (durvalumab) + FLOT before and after surgery in resectable gastric and gastroesophageal junction cancer. What the MATTERHORN trial showed
The New England Journal of Medicine has published the results of the phase III MATTERHORN trial in patients with resectable adenocarcinoma of the stomach and gastroesophageal junction. The trial compared perioperative FLOT with the addition of Imfinzi (durvalumab) versus FLOT with placebo. The main benefit was achieved in event-free survival.
In brief: what happened
The trial enrolled 948 patients: 474 in the Imfinzi (durvalumab) group and 474 in the placebo group.
- Two-year event-free survival was 67.4% with the Imfinzi (durvalumab) regimen versus 58.5% with FLOT without immune therapy.
- The pathologic complete response rate was 19.2% versus 7.2%.
- The rate of grade 3-4 adverse events was almost identical: 71.6% versus 71.2%.
Key numbers from the trial
Adding Imfinzi (durvalumab) reduced the risk of an event or death by 29% (HR 0.71; 95% CI 0.58-0.86; p<0.001). Two-year overall survival was 75.7% versus 70.4%, but the formal statistical threshold was not reached at this interim analysis. Immunotherapy did not affect the timing of the surgical stage of treatment.
Why this matters in practice
For resectable gastric and gastroesophageal junction cancer, FLOT has long been the standard of perioperative treatment. MATTERHORN shows that immune therapy can be added to this standard, yielding a benefit in event-free survival without a clear worsening of tolerability and without losing the surgical window.
Limitations / what is not changing yet
If we are dealing with metastatic disease, a different histology, a different treatment strategy, or a situation in which the surgical route is not confirmed, the MATTERHORN results cannot be applied directly.
When a second opinion is especially useful
- you are offered surgery only, with no discussion of systemic treatment beforehand;
- it is unclear whether perioperative FLOT is right for you;
- different clinics offer different treatment routes;
- you want to understand whether it makes sense to discuss adding Imfinzi (durvalumab).
What to prepare for the consultation
So that the discussion is specific:
- gastroscopy and biopsy;
- histopathology report;
- CT of the chest, abdomen and pelvis;
- results of laparoscopy, if it was performed;
- discharge summary with the clinical stage and the proposed treatment plan;
- list of comorbidities and medications.
Frequently Asked Questions
Is this regimen suitable for all patients with gastric cancer?
No. This concerns resectable adenocarcinoma of the stomach and gastroesophageal junction in the perioperative setting.
Is this already a new standard for everyone?
The data on event-free survival are very strong, but for overall survival the formal statistical threshold was not reached. That is why the regimen should be discussed specifically, not applied automatically.
Is surgery still needed after this regimen?
Yes. In the trial, the surgical stage remained a mandatory part of treatment.
More answers on the FAQ page.