Slide 1: IMA203CD8 Cell Therapy in PRAME-positive Solid Tumors - Phase 1a Dose Escalation Clinical Data Update
© Immatics. Not for further reproduction or distribution. IMA203CD8 Cell Therapy in PRAME - positive Solid Tumors - Phase 1a Dose Escalation Clinical Data Update December 11, 2025
Slide 2: Disclaimer
Disclaimer This presentation (“Presentation”) is provided by Immatics N . V . (“Immatics” or the “Company”) for informational purposes only . The information contained herein does not purport to be all inclusive and none of Immatics, any of its affiliates, any of its or their respective control pers
Slide 3: PRAME is expressed in more than 50 cancers
nzu c el (I M A203) P R AME Cell Therapy 295 % 210 % Anzutresgene autoleucel (anzu - cel, formerly IMA203), 1 Data on file: PRAME target prevalence is based on a proprietary initial mass spec - guided expression threshold applied to RNAseq and/or IHC data (approximate values, values between 95 - 100
Slide 4: Study Schema: IMA203CD8 in Solid Tumors Expressing PRAME
Study Schema: IMA203CD8 in Solid Tumors Expressing PRAME Ongoing Phase 1a Dose Escalation Study 4 Busse et al., ESMO - IO 2025 PRAME Testing a Biopsy or archived tissue Inclusion of PRAME - positive patients IMA203CD8 manu f a cturing (~2 weeks) Lymphodepletion Fludarabine 30mg/m 2 Cyclophosphamide
Slide 5: Demographics: Baseline Characteristics
Demographics: Baseline Characteristics 5 Efficacy - evaluable Population 2 Safety Population 1 Other 4 n=5 Synovial Sarcoma n=11 Ovarian Carcinoma n=11 Melan o m a 3 n=42 All Indications N=78 54 (38, 71) 40 (20, 66) 60 (35, 75) 62 (23, 85) 60 (20, 85) Age, median (range) 3 (60) 4 (36) 11 (100) 21 (5
Slide 6: Demographics: Treatment Experience
Demographics: Treatment Experience 6 Efficacy - evaluable Population 2 Safety P o pu l at i o n 1 Prior Therapy O the r 4 n=5 Synovial Sarcoma n=11 Ovarian Carcinoma n=11 Melanoma 3 n=42 All Indications N=78 Treatment, n (%) 5 (100) 8 (73) 3 (27) 27 (64) 47 (60) Radiation 5 (100) 11 (100) 11 (100) 4
Slide 7: IMA203CD8: Tolerability in Advanced Solid Tumors
IMA203CD8: Tolerability in Advanced Solid Tumors Overall Manageable Tolerability Profile 7 • Most frequent TEAEs were anticipated cytopenias associated with lymphodepletion • Expected and manageable CRS, mostly Grade 1 - 2, consistent with mechanism of action • Previously reported DLTs in 2 patients
Slide 8: IMA203CD8: Tumor Reduction During Dose Escalation
8 n=69 a, b Me lanoma (n=42 a ) Ovarian Carcinoma (n=11 b ) Synovial Sarcoma (n=11) Othe r c (n=5) 1 . 6 2 . 3 1 . 6 All (n=69) 36% (23/64) cORR 46% (32/69) OR R 78% (54/69) Tumor reduction 84% (58/69) DCR (at week 6) 9.2 mo (1.5, 36.4+) mDOR, (range) 14 mo mFU IMA203CD8: Tumor Reduction During Dose
Slide 9: IMA203CD8: Changes in Tumor Size Over Time During Dose Escalation
IMA203CD8: Changes in Tumor Size Over Time During Dose Escalation 9 Data cutoff Oct 27, 2025 Busse et al., ESMO - IO 2025 Deep and Durable Responses for up to 3+ Years 5 patients without post - baseline scan not depicted in plot: n=2 with melanoma deceased prior to first scan, n=1 with melanoma had
Slide 10: IMA203CD8 in Patients with Ovarian Carcinoma
IMA203CD8 in Patients with Ovarian Carcinoma Dose Escalation at Higher Doses ( ೦ DLS) Ongoing to Unlock Full Potential of IMA203CD8 10 Dose - dependent promising signal at higher doses ೦ DLS with 2 cPRs and 1 PR (all DL shown) Deep confirmed objective responses at higher doses ೦ DLS (all DL shown) n
Slide 11: Conclusions
Conclusions Towards Proof - of - concept for Tumor - agnostic Targeting of PRAME cancers with IMA203CD8 • M n bd hfd bedehy h ent oen ;fo d e do eh - mfoh f qa nh 2 ; 3 ho b en nhete h ; tyhf ne • Encouraging clinical anti - tumor activity after one - time infusion of IMA203CD8 already at a low medi
Slide 12: Thank You – Study Participants & Caregivers
University Hospital Dresden University Hospital Bonn University Hospital Würzburg University Hospital Hamburg Charité Berlin University Hospital Heidelberg University Medicine Mainz TUM University Hospital Munich IMA203CD8 Phase 1 Study Sponsor: Immatics Massachusetts General Hospital University of
Slide 13: Appendix
aoe Immatics Appendix
Slide 14: Phase 1a Dose Escalation Study Design
Phase 1a Dose Escalation Study Design Safety Population (N=78 * ) DL3 1 (n=7) DL4c (n=5) ~1.45 - 2.16 x 10 9 total TCR T cells DL5 (n=0) ~2.17 - 3.6 x 10 9 total TCR T cells DL6 (n=4) ~3.6 - 7.2 x 10 9 total TCR T cells DL7 (n=1) ~7.2 - 10 x 10 9 total TCR T cells DL4c - (n=3) ~1.45 - 2.16 x 10 9 to
Slide 15: Patient Populations Across All Dose Levels
Other (n=5) 15 Safety Population 1 (N=78) n=1 started lymphodepletion but pending infusion n=8 pending first post - baseline scan, thereof n=1 on DL5, n=2 on DL6, n=3 on DL7 E ffi c acy - e v aluable Population 2 (n=69) Melanoma (n=42) Ovarian Carcinoma (n=11, thereof n=5 at 2b,5} Synovial Sarcoma (
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) 16 Data cutoff Oct 27, 2025 Tolerability in synovial sarcoma was generally consistent with full IMA203CD8 tolerability profile n=11 Ongoing response until month 16 post i
Slide 17: Opportunity of IMA203CD8 across Broad Range of PRAME Expressing Indications
Opportunity of IMA203CD8 across Broad Range of PRAME Expressing Indications 17 Data on file; PRAME expression: evaluated biopsies (FFPE tissue) prior to treatment with anzutresgene autoleucel (anzu - cel, formerly IMA203) or IMA203CD8, melanoma: cutaneous melanoma, uveal melanoma, acral melanoma, me
Slide 18: IMA203CD8 and Anzu-cel (IMA203) in Cutaneous Melanoma
IMA203CD8 and Anzu - cel (IMA203) in Cutaneous Melanoma 18 • Promising IMA203CD8 dose escalation data at low median dose, but too early for conclusive comparison to anzu - cel • IMA203CD8 has entered higher dose levels at ~7.2 - 10 billion total TCR T cells outside melanoma to unlock its full clinic