October 20, 2023
Imfizini plus chemotherapy showed promising results as neoadjuvant chemotherapy in patients with gastric cancers.
AstraZeneca's Imfinzi (durvalumab), combined with standard-of-care FLOT neoadjuvant chemotherapy, has delivered positive results in an interim MATTERHORN Phase III trial analysis. This combination treatment has demonstrated a significant and clinically relevant enhancement in the pathologic complete response (pCR) rate, a key secondary endpoint, in patients with resectable early-stage and locally advanced (Stages II, III, IVA) gastric and gastroesophageal junction (GEJ) cancers, when compared to neoadjuvant chemotherapy alone.
The data revealed that Imfinzi combined with neoadjuvant FLOT chemotherapy resulted in a pCR rate of 19%, while the rate for patients treated with neoadjuvant chemotherapy alone was 7%. The difference in pCR rate was 12%, with an odds ratio (OR) of 3.08, indicating the significant superiority of the Imfinzi combination.
Moreover, the rate of either complete or near-complete responses was 27% for the Imfinzi combination and 14% for neoadjuvant chemotherapy alone.
BICR assessed summary results
Imfinzi plus chemo
Patients who achieved pCR %
% achieved near or complete response
The MATTERHORN trial will proceed as planned to evaluate the primary endpoint of event-free survival (EFS) and overall survival, the key secondary endpoint.
October 20, 2023
Keytruda Plus Trastuzumab Combo Shows Promise in HER2-Positive Gastric Cancer Trial
Merck has unveiled the outcomes of the Phase 3 KEYNOTE-811 trial, which investigated the efficacy of Keytruda (pembrolizumab) when utilized alongside trastuzumab and chemotherapy as the primary treatment for patients afflicted by HER2-positive advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma. This study focused on individuals with locally advanced unresectable or metastatic disease cases.
Following a median follow-up of 28.4 months, the Keytruda regimen demonstrated a statistically significant advancement in progression-free survival (PFS) within the entire advanced HER2-positive study population, reducing the risk of disease progression or mortality by 28% when compared to trastuzumab and chemotherapy alone.
Notably, the Keytruda regimen also yielded a clinically significant enhancement in PFS for patients whose tumours expressed PD-L1, risk of disease progression or death reduced by 30% compared to trastuzumab and chemotherapy alone.
In a subsequent interim analysis (with a median follow-up of 38.5 months), a positive trend in overall survival (OS), the trial's second primary endpoint, was noted for the Keytruda regimen when compared to trastuzumab and chemotherapy alone in the entire study population and the PD-L1 subgroup. Among patients with tumours expressing PD-L1, the median OS for those receiving the Keytruda regimen was 20.0 months, whereas those receiving trastuzumab and chemotherapy alone had a median OS of 15.7 months. Although these OS results did not reach statistical significance in this interim analysis, further follow-up is planned for a future OS analysis within this trial.