One-time infusion of IMA203CD8 PRAME cell therapy in the ongoing Phase 1 dose escalation/dose expansion trial achieved anti-tumor activity in platinum-resistant ovarian cancer and in uterine cancer with a 63% objective response rate (ORR), 50% confirmed ORR (cORR), including four complete responses, and longest ongoing response at 12 months Additional Phase 1 data for IMA203CD8 in heavily pretreated patients with synovial sarcoma showed deep and durable responses with a 67% ORR and 64% cORR, including one complete response, and ongoing responses up to ~3 years IMA203CD8 demonstrated a manageable and consistent tolerability profile across patient populations Clinical anti-tumor activity observed across tumor types (ovarian carcinoma, uterine cancer, melanoma, synovial sarcoma) with distinct biology and differing levels of PRAME expression, including lower PRAME levels in ovarian carcinoma Clinical profile of IMA203CD8 supports continued development in gynecologic cancers and expansion into other PRAME-positive solid tumors Determination of recommended phase 2 dose (RP2D) remains expected in 2026 Houston, Texas and Tuebingen, Germany, May 30, 2026 – Immatics N.V. (NASDAQ: IMTX, “Immatics” or the “Company”), the global leader in precision targeting of PRAME with multiple clinical-stage programs spanning cell therapies and bispecifics, today announced updated Phase 1 data for its IMA203CD8 PRAME TCR T-cell therapy in gynecologic cancers and synovial sarcoma at the Annual Meeting of the American Society for Clinical Oncology (ASCO) in Chicago, IL, USA.