Chimeric Therapeutics (CHM) Study Update summary

Study design and objectives

• Phase 1/2 trial aims to determine the recommended Phase 2 dose and evaluate safety and response rate of CHM CDH17 in advanced colorectal, gastric, and intestinal neuroendocrine tumors.

• Phase 1 will enroll up to 15 patients, leading to dose selection and expansion into indication-specific Phase 2 cohorts.

• CHM CDH17 is a 3rd generation CAR-T cell therapy targeting CDH17, a biomarker linked to poor prognosis in GI tumors.

Study progress and interim results

• Advanced to dose level 2 (150 million cells) after no safety concerns at dose level 1.

• Dose level 2 patient showed stable disease and ~12% tumor shrinkage at first scan post-treatment.

• No off-target effects or gastrointestinal toxicity observed, allowing further patient enrollment at dose level 2.

• Dose level 1 patient remains with stable disease at month 8, with ~18% tumor shrinkage and no other treatments.

Safety and efficacy signals

• No new safety findings or off-target effects reported at either dose level.

• Early anti-tumor activity observed, with RECIST criteria confirming stable disease and measurable tumor shrinkage.

• Durability of response suggested by ongoing stable disease in dose level 1 patient over 8 months.