Slide 1: IMA203 PRAME Cell Therapy in Advanced Melanoma - Phase 1b Dose Expansion Clinical Data Update
IMA203 PRAME Cell Therapy in Advanced Melanoma - Phase 1b Dose Expansion Clinical Data Update May 31, 2025 Data cut - off April 7, 2025 Delivering the Power of T cells to Cancer Patients © Immatics. Not for further reproduction or distribution.
Slide 2: Background and Key Takeaways
Background and Key Takeaways • Frequent recurrence and limited long - term survival with unresectable or metastatic melanoma highlight the critical need for new treatments that deliver deeper, more durable responses 1 - 3 • IMA203 is a PRAME - directed TCR T - cell therapy engineered to recognize an
Slide 3: PRAME Is Expressed in More Than 50 Cancers
PRAME Is Expressed in More Than 50 Cancers PRAME prevalence in selected indications % PRAME+ patients 1 Indication 95% Cutaneous Melanoma 95% Uterine Carcinoma 95% Uterine Carcinosarcoma 95% Synovial Sarcoma 90% Uveal Melanoma 90% Mucosal Melanoma 85% Ovarian Carcinoma Subtypes 70% Squamous Cell NSC
Slide 4: Phase 1 Study Design: IMA203 in Advanced Solid Tumors Expressing PRAME
Phase 1 Study Design: IMA203 in Advanced Solid Tumors Expressing PRAME Key Objectives Primary: • Tolerability • Determination of RP2D (Phase 1a) Secondary: • IMA203 T cell engraftment, persistence • Efficacy Key Eligibility Criteria • Confirmed advanced and/or metastatic solid tumor • Patients ≥ 18
Slide 5: IMA203 Phase 1 Study: Patient Disposition
IMA203 Phase 1 Study: Patient Disposition 5 1 Melanoma efficacy population excludes 1 patient with uveal melanoma with ongoing unconfirmed PR from cORR; 2 Mucosal melanoma n=2, melanoma of unknown primary n=1; RP2D: 1 - 10x10 9 TCR T cells; DL4: 0.2 - 1.2x10 9 TCR T cells/m 2 BSA; DL: dose level. To
Slide 6: IMA203 Phase 1 Study: Baseline Characteristics & Treatment Experience
IMA203 Phase 1 Study: Baseline Characteristics & Treatment Experience CM, cutaneous melanoma; ECOG, Eastern Cooperative Oncology Group; ICI, immune checkpoint inhibitor; LDH, lactate dehydrogenase; MM, mucosal melanoma; TCR, T - cell receptor; UkM, melanoma of unknown primary; UM, uveal melanoma. 6
Slide 7: IMA203 Safety: Adverse Events Occurring in ≥20% of Patients
IMA203 Safety: Adverse Events Occurring in ≥20% of Patients N=74 Patients Across All Dose Levels in Phase 1a/b (Total Safety Population) 7 Patients are counted only once per adverse event and severity classification. 1 Two patients with disease progression after first IMA203 infusion received explor
Slide 8: IMA203: Best Overall Response in Heavily Pretreated Patients with Metastatic Melanoma
IMA203: Best Overall Response in Melanoma Efficacy Population 56% Confirmed Objective Responses in Heavily Pretreated Patients with Metastatic Melanoma 8 *Maximum change of target lesions and RECIST1.1 response at different timepoints. 1 Patient out of study due to PD (external assessment); 2 Patien
Slide 9: IMA203: Duration of Response in Melanoma
IMA203: Duration of Response in Melanoma Efficacy Population Prolonged Ongoing Responses up to 2.5+ Years after Treatment 9 1 Patient out of study due to PD (external assessment); 2 Patient out of study at data - cut (withdrew consent); 3 Includes melanoma (other) n=3: mucosal melanoma n=2, melanoma
Slide 10: IMA203: Survival Outcomes in Melanoma
IMA203: Survival Outcomes in Melanoma Efficacy Population 10 Median Progression Free Survival Median Overall Survival Data cut - off Apr 7, 2025 ASCO 2025 All 1 Melanoma n=33 Uveal Me l a n o ma n=16 C u t ane o u s Me l a n o ma n=14 6.1 (1.4, 34.0+) 14.4 8.5 (1.4, 32.9) 8.7 6.0 (1.4 , 34.0+) 14.4
Slide 11: IMA203: Enhanced mPFS of >1 Year in Melanoma Patients with Deep Responses
IMA203: Enhanced mPFS of >1 Year in Melanoma Patients with Deep Responses Data cut - off Apr 07, 2025 11 • 42% (14/33) patients in dose expansion have a deep response (≥50% tumor reduction) • This subgroup of patients has highly medically meaningful mPFS of more than 1 year • Patients with <50% tumo
Slide 12: IMA203: Responses of Metastases Throughout the Body Including Liver
17 4 11 23 14 41 n - 46.2% - 22.1% - 62.6% - 54.2% - 44.9% - 48.9% Med i a n s h ri n k a ge IMA203: Responses of Metastases Throughout the Body in Melanoma Efficacy Population Shrinkage in Difficult - to - Treat Target Lesions Including Liver 12 Other: brain, kidney, pelvis, pericardium, pleura, bo
Slide 13: IMA203 PRAME Cell Therapy: Conclusions
IMA203 PRAME Cell Therapy: Conclusions Extended Phase 1 Data Continues to Show Strong Anti - tumor Activity and Durability • IMA203 PRAME - directed TCR T - cell therapy exhibited favorable tolerability, with anticipated lymphodepletion - associated cytopenias, mostly mild - to - moderate CRS, infre
Slide 14: SUPRAME: A Randomized Phase 3 Trial of IMA203 vs Investigator's Choice
SUPRAME: A Randomized Phase 3 Trial of IMA203 PRAME - directed TCR T - cell Therapy vs Investigator’s Choice in Unresectable or Metastatic Melanoma post ICI Actively Enrolling, >50 Sites Planned across North America and Europe 14 IMA203 n=180 Investigator’s choice n=180 Primary Endpoint • P F S Key
Slide 15: IMA203 Phase 1 Study Sponsor and Participating Sites
15 IMA203 Phase 1 Study Sponsor: Immatics University Hospital Dresden University Hospital Bonn University Hospital Würzburg University Hospital Hamburg Charité Berlin University Hospital Heidelberg University Medicine Mainz Columbia U n iv er sity University of Pittsburgh MD Anderson Cancer Center U
Slide 16: Appendix
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Slide 17: IMA203 Phase 1 Study: Baseline Characteristics Including Melanoma Dose Escalation Population
IMA203 Phase 1 Study: Baseline Characteristics & Treatment Experience Including Melanoma Dose Escalation Population Data cut - off Apr 7, 2025 17 Melanoma Efficacy Population Melanoma Dose Escalation Population Total Safety Population Treatment Experience 4.04 (1.30, 10.20) 0.586 (0.099, 2.09) 2.34
Slide 18: IMA203: Significant Shift in PFS and OS Between Dose Escalation & Dose Expansion
IMA203: Significant Shift in PFS and OS Between Dose Escalation & Dose Expansion PFS of 6 Months and OS of 16 Months in Melanoma Efficacy Population Progression Free Survival Data cut - off Apr 07, 2025 18 Overall Survival mPFS N 2.6 months 11 Dose Escalation 6.1 months 33 Dose Expansion mOS N 6.3 m
Slide 19: Tolerability Profile of IMA203 Across All Dose Levels in Phase 1a/b
Tolerability Profile of IMA203 Across All Dose Levels in Phase 1a/b All ≥ Grade 3 Adverse Events (N=74) ≥ Grade 3 Adverse event ( System organ class , Preferred term) % No. 100 .0 74 Patients with any adverse event 13.5 10 Adverse Events of Special Interest 10 .8 8 Cytokine release syndrome 1 4 .1 3
Slide 20: CRS Events and Interventions After IMA203 Infusion
CRS Events and Interventions After IMA203 Infusion in Melanoma Efficacy Population Manageable and Consistent with Mechanism of Action • Median day of onset (range): 1 (0, 3) • Median duration, days (range): 9 (2, 27) • Most CRS resolved by day 14 • No long - term CRS CRS Interventions Data cut - off
Slide 21: Patients with Melanoma Treated with IMA203 in Phase 1b Dose Expansion
Melanoma Efficacy Population (n=33) Patients with Melanoma Treated with IMA203 in Phase 1b Dose Expansion Reason for Progression Comment BOR (Max % change of target lesions) BOR Total infused dose TCR - T cells 1 [x10 9 ] Prior treatments No of prior treatment lines Indication Patient ID Ongoing res
Slide 22: Patients with Melanoma Treated with IMA203 in Phase 1b Dose Expansion
Melanoma Efficacy Population (n=33) Patients with Melanoma Treated with IMA203 in Phase 1b Dose Expansion Reason for Progression Comment BOR (Max % change of target lesions) BOR Total infused dose TCR - T cells 1 [x10 9 ] Prior treatments No of prior treatment lines Indication Patient ID Non - targe
Slide 23: Patients with Melanoma Treated with IMA203 in Phase 1b Dose Expansion
Melanoma Efficacy Population (n=33) Patients with Melanoma Treated with IMA203 in Phase 1b Dose Expansion Reason for Progression Comment BOR (Max % change of target lesions) BOR Total infused dose TCR - T cells 1 [x10 9 ] Prior treatments No of prior treatment lines Indication Patient ID New lesions