ExpreS2ion Biotech's Early-stage Immunotherapy Trial Clears Safety Review

04:09 AM EDT, 08/12/2026 (MT Newswires) -- ExpreS2ion Biotech Holding (EXPRS2.ST) said Wednesday an independent safety monitoring board found no dose-limiting toxicities in a phase 1 trial of its ES2B-C001 immunotherapy targeting HER2-expressing cancers. The board recommended expanding the highest-dose cohort of 450 micrograms by three patients, booting the safety and immunogenicity dataset ahead of the study's primary readout, expected by the end of 2026. Preliminary data showed anti-HER2 antibody responses in 12 of 13 evaluable patients, including all five who completed the five-dose regimen. The biotechnology company now expects to begin phase 2 testing in the second half of 2027, compared with a previous target of mid-2027, to allow regulatory discussions in Europe and the US.