AstraZeneca reports ‘positive’ results from interim analysis of MATTERHORN trial

AstraZeneca reports “positive” results from a planned interim analysis of the MATTERHORN Phase III trial showed treatment with AstraZeneca’s Imfinzi in combination with standard-of-care FLOT neoadjuvant chemotherapy demonstrated a statistically significant and clinically meaningful improvement in the key secondary endpoint of pathologic complete response, or pCR, versus neoadjuvant chemotherapy alone for patients with resectable, early-stage and locally advanced gastric and gastroesophageal junction, or GEJ, cancers. These results will be presented today at the European Society for Medical Oncology, or ESMO, Congress 2023 in Madrid, Spain, the company noted. Treatment with Imfinzi plus neoadjuvant FLOT chemotherapy resulted in a pCR rate of 19% versus 7% for patients treated with neoadjuvant chemotherapy alone as assessed by blinded independent central review. The rate of either complete or near-complete responses was 27% with the Imfinzi combination and 14% with neoadjuvant chemotherapy alone. The trial, which is assessing Imfinzi in combination with FLOT chemotherapy as a perioperative treatment, will continue as planned to assess the primary endpoint of event-free survival, or EFS, and the key secondary endpoint of overall survival, or OS, to which the trial team, investigators and participants remain blinded.