DISCLAIMER

The contents of the presentation are designed for educational and scientific exchange purposes and are not promotional. They may contain information on investigational products or investigational uses of approved products. No conclusions regarding safety and/or efficacy for such investigational products or uses may be made.

SUMMARY

This exploratory post hoc safety analysis of the ongoing phase 3 HERIZON-GEA-01 trial evaluated treatment-emergent adverse events (TEAEs) adjusted for treatment exposure in patients with HER2-positive metastatic gastric or gastroesophageal adenocarcinoma who received zanidatamab (zani) plus chemotherapy (CT) with or without tislelizumab (tis) or trastuzumab (tras) plus CT. Safety was assessed in 901 patients who received at least one treatment dose (zani+tis+CT, n=294; zani+CT, n=305; tras+CT, n=302). Median treatment duration was 9.9 months, 7.1 months, and 6.9 months, respectively. Exposure-adjusted event rates (EAERs) per 100 patient-months for any-grade TEAEs were 187.8 (95% CI, 183.3–192.3), 189.2 (95% CI, 184.5–194.0), and 190.2 (95% CI, 185.0–195.4), respectively; corresponding grade ≥3 TEAE EAERs were 24.0 (95% CI, 22.4–25.6), 22.1 (95% CI, 20.5–23.8), and 24.1 (95% CI, 22.3–26.0). Exposure-adjusted diarrhea rates per 100 patient-months were 22.8 (95% CI, 21.3-24.5), 23.4 (95% CI, 21.8-25.2), and 14.0 (95% CI, 12.6-15.5) for any-grade events and 2.6 (95% CI, 2.1-3.2), 2.6 (95% CI, 2.1-3.2), and 1.7 (95% CI, 1.2-2.7) for grade ≥3 events, respectively. Within each treatment arm, TEAE incidence decreased from cycles 1–3, 4-6, and 7–9.

ClinicalTrials.gov ID: NCT05152147