Immatics N.v. · NASDAQ:IMTX
Immatics — 2025 ESMO Immuno-Oncology Congress
16 slides from Immatics's conference presentation, Dec 11, 2025
Slide 1: A Phase 1 Trial of IMA203CD8, a PRAME-directed TCR T-cell Therapy in PRAME-positive Solid Tumors
Copies of this presentation obtained through QR, AR and/or text key codes are for personal use only and may not be reproduced without written permission of the authors. A Phase 1 Trial of IMA203CD8, a PRAME-directed TCR T-cell Therapy in PRAME-positive Solid Tumors Antonia Busse1, Dejka M. Araujo2,
Slide 2: Declaration of Interests
Declaration of Interests Employment or leadership position: None Consultancy / advisory activities: None Ownership of shares, stocks or investment funds: None Patents, copyrights, licensing rights or royalties: None Honoraria (e.g., for lectures, advisory boards, consultancy): Novartis; Gilead; Hexa
Slide 3: IMA203CD8: Precision Targeting of PRAME Across Tumor Types with Both CD8+ and CD4+ T Cells
IMA203CD8: Precision Targeting of PRAME Across Tumor Types with Both CD8+ and CD4+ T Cells PRAME is expressed in >50 cancers Mechanism of action of IMA203CD8 % PRAME+ Indication Patients1 Cutaneous melanoma 95% Uterine carcinoma 95% Uterine carcinosarcoma 95% Synovial sarcoma 95% Uveal melanoma2 90%
Slide 4: Study Schema: IMA203CD8 in Solid Tumors Expressing PRAME
Study Schema: IMA203CD8 in Solid Tumors Expressing PRAME Ongoing Phase 1a Dose Escalation Study Patient Journey SCREENING / MANUFACTURING TREATMENT / OBSERVATION FU Lymphodepletion ± Low Dose IL-2c Key Eligibility Criteria Fludarabine 30mg/m2 1M IU SUBQ QD x 5 days, then HLA-A*02:01 Testing Cyclopho
Slide 5: Demographics: Baseline Characteristics
Demographics: Baseline Characteristics Safety Population1 Efficacy-evaluable Population2 All Indications Melanoma3 Ovarian Carcinoma Synovial Sarcoma Other4 N=78 n=42 n=11 n=11 n=5 Age, median (range) 60 (20, 85) 62 (23, 85) 60 (35, 75) 40 (20, 66) 54 (38, 71) Female, n (%) 46 (59) 21 (50) 11 (100)
Slide 6: Demographics: Treatment Experience
Demographics: Treatment Experience Safety Efficacy-evaluable Population2 Population1 Prior Therapy All Indications Melanoma3 Ovarian Carcinoma Synovial Sarcoma Other4 N=78 n=42 n=11 n=11 n=5 Treatment, n (%) Radiation 47 (60) 27 (64) 3 (27) 8 (73) 5 (100) Systemic treatment 77 (99) 41 (98) 11 (100)
Slide 7: IMA203CD8: Tolerability in Advanced Solid Tumors
IMA203CD8: Tolerability in Advanced Solid Tumors Overall Manageable Tolerability Profile TEAEs in ≥20% of patients Adverse events of special interest N=78a N=78a • Most frequent TEAEs were cytopenias Preferred term, n (%) Any grade Grade ≥3 CRS, any grade, n (%) 74 (95) Neutropenia 67 (86) 66 (85) G
Slide 8: IMA203CD8: Tumor Reduction During Dose Escalation
IMA203CD8: Tumor Reduction During Dose Escalation All Dose Levels Across Various PRAME-expressing Indications Melanoma Ovarian Synovial Otherc (n=42a) Carcinoma (n=11b) Sarcoma (n=11) (n=5) Median dose [x109] TCR T cells 1.6 2.3 1.6 DCR (at week 6) 83% (35/42) 73% (8/11) 100% (11/11) All n=69 n=69 a
Slide 9: IMA203CD8: Changes in Tumor Size Over Time During Dose Escalation
IMA203CD8: Changes in Tumor Size Over Time During Dose Escalation Deep and Durable Responses for up to 3+ Years Months Post IMA203CD8 Infusion 5 patients without post-baseline scan not depicted in plot: n=2 with melanoma deceased prior to first scan, n=1 with melanoma had non-evaluable measurements
Slide 10: Conclusions
Conclusions • PRAME is an intracellular cancer antigen that is targetable across multiple cancers • IMA203CD8 PRAME-directed TCR T-cell therapy harnesses collaborative antitumor activity of both CD8 and CD4 T-cells • One-time infusion of IMA203CD8 demonstrates tolerability at increasing dose-levels
Slide 11: Thank You – Study Participants & Caregivers
Thank You – Study Participants & Caregivers United States Germany Massachusetts General Hospital University Hospital Hamburg University of Pittsburgh Medical Center Charité Berlin Fox Chase Cancer Center University Hospital Dresden University Hospital Bonn MD Anderson Cancer University Hospital Cent
Slide 12: Appendix
Appendix 12
Slide 13: Phase 1a Dose Escalation Study Design
Phase 1a Dose Escalation Study Design Safety Population (N=78*) Data Supplement to Busse et al., ESMO-IO 2025 DL31 (n=7) NCT03686124 ~0.36 - 0.86 x 109 total TCR T cells DL4a2 (n=38) ~0.87 - 1.44 x 109 total TCR T cells DL4b3 (n=4) ~1.45 - 2.16 x 109 total TCR T cells Cohort without IL-2 Cohort with
Slide 14: Patient Populations
Patient Populations Various PRAME-Expressing Indications Across All Dose Levels Data Supplement to Busse et al., ESMO-IO 2025 NCT03686124 Safety Population1 n=1 started lymphodepletion but pending infusion (N=78) n=8 pending first post-baseline scan: • n=1 at DL3 • n=1 at DL4c • n=1 at DL5- • n=1 at
Slide 15: IMA203CD8 in Patients with Ovarian Carcinoma
IMA203CD8 in Patients with Ovarian Carcinoma Dose Escalation at Higher Doses Ongoing to Unlock full Potential of IMA203CD8 Data Supplement to Busse et al., ESMO-IO 2025 Dose-dependent promising signal at Deep confirmed objective responses NCT03686124 higher doses ≥DL5 with 2 cPRs and 1 PR at higher
Slide 16: IMA203CD8 in Patients with Synovial Sarcoma
IMA203CD8 in Patients with Synovial Sarcoma Promising Clinical Activity with Deep and Durable Responses at Low Doses (DL1-DL4a) Data Supplement to Busse et al., ESMO-IO 2025 NCT03686124 n=11 Ongoing response until month 16 post infusion* Months Post IMA203CD8 Infusion Tolerability in synovial sarcom