Targeting PRAME+ Tumors with IMA203CD8, a PRAME - directed TCR T - cell Therapy: Results from a Phase 1 Study Antonia Busse 1 , Dejka M. Araujo 2 , Winfried Alsdorf 3 , Oladapo Yeku 4 , Tobias A.W. Holderried 5,6 , Leonel F. Hernandez - Aya 7 , Sarah Taylor 8 , Dirk Jaeger 9 , Manik Chatterjee 10 , Anthony J. Olszanski¹¹, Eva M. Wagner - Drouet¹², Peter Herhaus¹³, Katrin Wetzko 14 , Apostolia M. Tsimberidou², Friederike Schmitz 5 , Diwakar Davar 15 , Karine Pozo 16 , Liane Preussner 17 , Cedrik M. Britten 17 , Martin Wermke 18 Prof. Dr. med. Antonia Busse Proffered paper presentation , abstract #7231 1 Charité Medical University Hospital, Berlin, Germany; 2 The University of Texas MD Anderson Cancer Center, Houston, TX, USA; 3 Department of Hematology and Oncology , University Hospital Hamburg Eppendorf, Hamburg, Germany; 4 Massachusetts General Hospital, Boston, MA, USA; 5 University of Bonn, University Hospital Bonn, Medical Clinic and Polyclinic III Internal Medicine with a focus on Oncology , Hematology , and Rheumatology , Bonn, Germany; 6 Clinical Division of Hematology , Department of Internal Medicine, Medical University of Graz, Graz, Austria; 7 University of Miami, Miami, FL, USA; 8 University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA; 9 University Hospital Heidelberg, Heidelberg, Germany and Translational Oncology /Early Clinical Trial Unit (ECTU); 10 Comprehensive Cancer Center Mainfranken, University Hospital Würzburg, Würzburg, Germany; 11 Department of Hematology / Oncology , Fox Chase Cancer Center, Philadelphia, PA, USA; 12 University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany; 13 TUM School of Medicine and Health, Department of Internal Medicine III, University Medical Center, Technical University of Munich, Germany; 14 University Hospital Dresden, Dresden, Germany; 15 University of Pittsburgh Medical Center (UPMC), Hillman Cancer Center, Pittsburgh, PA, USA; 16 Immatics US, Houston, TX, USA; 17 Immatics Biotechnologies GmbH, Tuebingen , Germany; 18 TU Dresden, Carl - Gustav - Carus Faculty of Medicine, NCT/UCC Early Clinical Trial Unit, Dresden, Germany. 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
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 2 Declaration of Interests Prof. Dr. med. Antonia Busse , abstract #7231 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 ( eg , for lectures, advisory boards, consultancy): Novartis; Gilead; Hexal ; BMS; Roche; MSD; AstraZeneca Research funding: Novartis Other financial relationships: None Non - financial interests: None
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 3 IMA203CD8: A Systemic TCR T - cell Therapy Designed to Target the Intracellular Tumor Antigen PRAME Prof. Dr. med. Antonia Busse , abstract #7231 IMA203CD8 is an investigational therapy, and its use has not been proven to be safe or effective. It has not been approved by th e FDA or any other regulatory agency outside of the US. a Data on file: PRAME target prevalence is based on a proprietary mass spec - guided expression threshold applied to RNAseq data (approximate values; values between 95% - 100% shown as 95%). b Includes the following subtypes: clear cell carcinoma, endometrioid carcinoma, serous cystadenocarcinoma. CD, cluster of differentiation; FDA, US Food and Drug Administration; HER2, human epidermal growth factor receptor 2; HLA, hu man leukocyte antigen; NSCLC, non - small cell lung cancer; PRAME, preferentially expressed antigen in melanoma; RNAseq , RNA sequencing; TCR, T - cell receptor; Th1, T helper 1. Data cutoff: August 7, 2026 % PRAME+ patients a Indication 95% Cutaneous melanoma 95% Uterine carcinoma 95% Uterine carcinosarcoma 95% Synovial sarcoma 90% Uveal melanoma 90% Mucosal melanoma 85% Ovarian carcinoma subtypes b 70% Squamous cell NSCLC 65% Triple - negative breast carcinoma 45% Small cell lung cancer 45% Esophageal carcinoma subtype 40% Kidney carcinoma subtype 35% Cholangiocarcinoma 30% HER2 - enriched breast carcinoma 25% Adenocarcinoma NSCLC 25% Head & neck squamous cell carcinoma 20% Hepatocellular carcinoma 20% Bladder carcinoma PRAME is expressed in >50 cancers Mechanism of action Tumor cell
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 4 Phase 1 Multicenter Trial of IMA203CD8 in PRAME+ Solid Tumors Prof. Dr. med. Antonia Busse , abstract #7231 IMA203 - 101: NCT03686124; Based on initial safety data observed with anzu - cel (IMA203), IMA203CD8 dose escalation was initiated at DL3. Total TCR T cells calculated from defined number of TCR T cells /m 2 BSA per dose level î 1.8 m 2 BSA. a Dose level ≥DL4c is evaluated “ IL - 2, starting without IL - 2. If tolerable, add IL - 2 at the same dose or escalate to next dose without IL - 2; outpatient IL - 2 admi nistration at investigator’s discretion. Anzu - cel, anzutresgene autoleucel; bid, twice daily; BSA, body surface area; DL, dose level; ECOG, Eastern Cooperative Oncology Group; HLA, human le uk ocyte antigen; IL, interleukin; IU, international unit; PRAME, preferentially expressed antigen in melanoma; PS, performance sta tus; qd , once daily; RP2D, recommended phase 2 dose; SOC, standard of care; SUBQ, subcutaneous; TCR, T - cell receptor. Data cutoff: August 7, 2026 PRAME Testing Biopsy or archived tissue No longer required for indications with high PRAME prevalence, including ovarian and uterine cancer, melanoma, and synovial sarcoma IMA203CD8 Manufacturing (~2 weeks) Lymphodepletion Fludarabine 30 mg/m 2 Cyclophosphamide 500 mg/m 2 days - 6 to - 3 ц Low Dose IL - 2 a 1M IU SUBQ QD, days 3 - 5, then 1M IU SUBQ BID, days 6 - 10 Leukapheresis HLA - A*02:01 Testing (blood) Patient Journey SCREENING/MANUFACTURING TREATMENT/OBSERVATION FOLLOW UP IMA203CD8 one - time infusion Dose escalation completed Enrichment at relevant DLs (≥DL4c): ~1.2 – 12.5 billion total TCR T cells DL3 (n=7) 0.44 - 1.00 × 10 9 total TCR T cells DL4a (n=38) 0.93 - 1.86 × 10 9 total TCR T cells DL4b (n=4) 1.49 - 2.05 п 10 9 total TCR T cells DL5 (n=7) 1.95 - 4.30 п 10 9 total TCR T cells DL6 (n=15) 3.55 - 8.22 п 10 9 total TCR T cells DL7 (n=17) 4.26 - 12.50 × 10 9 total TCR T cells Dose Escalation Scheme ц Low Dose IL - 2 a Key Objectives Primary: • Tolerability • Determination of RP2D Secondary: • Efficacy • Pharmacokinetics Key Eligibility Criteria • Advanced or metastatic solid tumors • Age ≥ 18 years • ECOG PS 0 - 1 • HLA - A*02:01 positive • PRAME positive • No available SOC treatment options • Measurable disease (RECIST 1.1) • Adequate organ function DL4c (n=9) 1.15 - 3.06 п 10 9 total TCR T cells
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 5 Patient Disposition Prof. Dr. med. Antonia Busse , abstract #7231 Gynecologic indications include ovarian cancer and uterine cancer ; melanoma includes cutaneous , uveal , mucosal , acral melanoma , and melanoma of unknown primary ; other indications include breast and non - small cell lung cancer . a All patients who started lymphodepletion . b All patients who received IMA203CD8 infusion and had ≥1 postbaseline scan, progressive disease or death. DL, dose level; EOT, end of treatment. Data cutoff: August 7, 2026 Safety Population a N=98 Efficacy - evaluable Population b n=90 Gynecologic Indications n=27 Melanoma n=44 Synovial Sarcoma n=12 Other n=7 n=1 lymphodepleted, but not infused n=4 pending first postbaseline scan n=1 consent withdrawn before assessment n=1 EOT before first scan n=1 no measurable disease at baseline n=7 n=20 n=28 n=16 n=11 n=1 n=2 n=5 <DL4c ≥DL4c
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 6 Baseline Characteristics Prof. Dr. med. Antonia Busse , abstract #7231 a All patients who started lymphodepletion. b All patients who received IMA203CD8 infusion and had ≥1 postbaseline scan, progressive disease or death. Gynecologic indications include ovarian cancer and uterine cancer ; melanoma includes cutaneous , uveal , mucosal , acral melanoma , and melanoma of unknown primary ; other indications include breast cancer and non - small cell lung cancer . c Two patients were excluded from the target lesion analysis due to unavailable target lesion measurements at the time of data cut off. ECOG, Eastern Cooperative Oncology Group; LDH, lactate dehydrogenase; PS, performance status; SPD, sum of longest diameter; U LN, upper limit of normal. Data cutoff: August 7, 2026 Efficacy - evaluable Population b Safety Population a Other n=7 Synovial Sarcoma n=12 Melanoma n=44 Gynecologic Indications n=27 All N=98 56 (38 - 71) 46 (20 - 66) 62 (23 - 85) 58 (35 - 75) 58 (20 - 85) Median age (range), years 4 (57) 4 (33) 22 (50) 27 (100) 63 (64) Female, n (%) 4 (57) 2 (17) 21 (48) 10 (37) 40 (41) ECOG PS 1, n (%) 5 (71) 4 (33) 21 (48) 11 (41) 43 (44) LDH ≥1 × ULN, n (%) 6.4 (3.9 - 14.7) 8.1 (1.2 - 41.1) 7.9 (1.3 - 43.4) 6.2 (1.1 - 21.6) 6.8 (1.1 - 43.4) Median target lesion SLD (range), cm c 6 (5 - 25) 8 (1 - 16) 4 (1 - 25) 5 (1 - 25) 5 (1 - 25) Median number of tumor lesions (range) c 3 (43) 1 (8) 25 (57) 14 (52) 45 (46) Liver metastasis, n (%) 1 (14) 0 (0) 7 (16) 0 (0) 9 (9) Brain metastasis, n (%) 4 (57) 2 (17) 7 (16) 3 (11) 16 (16) Bone metastasis, n (%) 2 (29) 1 (8) 9 (20) 17 (63) 32 (33) Peritoneal disease, n (%)
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 7 Treatment Experience Prof. Dr. med. Antonia Busse , abstract #7231 Efficacy - evaluable Population b Safety Population a On Study Other n=7 Synovial Sarcoma n=12 Melanoma n=44 Gynecologic Indications n=27 All N=98 1.95 (1.47 - 10.00) 1.59 (0.89 - 10.00) 1.67 (0.44 - 11.80) 3.55 (0.47 - 12.50) 1.81 (0.44 - 12.50) Total infused dose TCR T cells [ × 10 9 ], median (range) Efficacy - evaluable Population b Safety Population a Prior Therapy Other n=7 Synovial Sarcoma n=12 Melanoma n=44 Gynecologic Indications n=27 All N=98 6 (86) 7 (100) 9 (75) 12 (100) 31 (70) 43 (98) 5 (19) 27 (100) 53 (54) 97 (99) Treatment, n (%) Radiation Systemic treatment 4 (2 - 7) 6 (86) 2 (1 - 5) 5 (42) 3 (0 - 9) 37 (84) 4 (1 - 7) 22 (81) 3 (0 - 9) 77 (79) Lines of systemic treatment, median (range) ≥3, n (%) 6 (86) 7 (100) - - - 5 (71) 0 0 12 (100) - - - 5 (42) 1 (8) 39 (89) 14 (32) - - - 15 (34) 15 (34) 5 (19) 27 (100) 24 (100) 19 (79) 1 (0 - 4) 23 (85) 0 55 (56) 68 (69) - - - 54 (55) 18 (18) Immune checkpoint inhibitors, n (%) Chemotherapy, n (%) Ovarian cancer only (n=24): Lines of prior platinum - based therapy, n (%) Platinum - resistant, n (%) Lines post - platinum resistance, median (range) Targeted therapies ( ie , ADCs, TKIs), n (%) TCR - based therapies, n (%) a All patients who started lymphodepletion. b All patients who received IMA203CD8 infusion and had ≥1 postbaseline scan, progressive disease or death. Gynecologic indications include ovarian cancer and uterine cancer ; melanoma includes cutaneous , uveal , mucosal , acral melanoma , and melanoma of unknown primary ; other indications include breast cancer and non - small cell lung cancer . ADC, antibody drug conjugate; TKI, tyrosine kinase inhibitor; TCR, T - cell receptor. Data cutoff: August 7, 2026
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 8 Tolerability in Advanced Solid Tumors Prof. Dr. med. Antonia Busse , abstract #7231 a All patients who started lymphodepletion, including 1 patient who did not receive IMA 203 CD 8 cells . b 2 events met DLT criteria but did not limit dose escalation : 1 in an enrichment cohort at DL 5 and 1 at highest dose, DL 7 ( 1 / 6 patients), both within protocol - defined dose - finding rules . c Possibly related grade 5 event as previously reported was determined by the PI to be unlikely related to IMA 203 CD 8 after complete assessment . Patient died from sepsis that was aggravated by immunosuppression from fludarabine/cyclophosphamide (possibly related), a grade 4 HLH event, the toxicity management, and rapidly progressing disease . CARTOX, CAR T - cell therapy – associated toxicity ; CRS, cytokine release syndrome ; DL, dose level ; DLT, dose - limiting toxicity ; HLH, hemophagocytic lymphohistiocytosis ; ICANS, immune effector cell – associated neurotoxicity syndrome ; PI, principal investigator ; MTD, maximum tolerated dose ; TEAE, treatment - emergent adverse event . Data cutoff: August 7, 2026 • Most frequent TEAEs were cytopenias associated with lymphodepletion • CRS was mostly grade 1 - 2 • DLTs in 4 of 98 patients: 1. DL4b: grade 4 neurotoxicity/CRS with grade 3 HLH 2. DL4b: grade 3 CRS 3. DL5: grade 3 ICANS b 4. DL7: grade 4 skin infection b • Late grade 3 - 4 N - ICAHT in 5 patients was manageable with supportive treatment ; all improved to grade ≤2 at a median of 69 days postinfusion (range, 42 – 121) • No IMA203CD8 - related grade 5 event c • MTD not reached with doses up to 12.5 billion IMA203CD8 cells TEAEs in ≥20% of Patients ( N=98 a ) Grade ≥3 Any grade Preferred term, n (%) 97 (99) 98 (100) Patients with any adverse event 87 (89) 88 (90) Neutropenia 54 (55) 78 (80) Anemia 36 (37) 71 (72) Thrombocytopenia 2 (2) 64 (65) Nausea 45 (46) 45 (46) Lymphopenia 5 (5) 39 (40) Rash 6 (6) 37 (38) Fatigue 12 (12) 37 (38) Transaminase elevation 2 (2) 34 (35) Hypokalemia 0 33 (34) Constipation 0 28 (29) Vomiting 3 (3) 26 (27) Abdominal pain 23 (23) 25 (26) Leukopenia 2 (2) 23 (23) Hyponatremia 0 23 (23) Pyrexia 3 (3) 21 (21) Hypophosphatemia 3 (3) 20 (20) Diarrhea 1 (1) 20 (20) Headache Adverse Events of Special Interest ( N=98 a ) 94 (96) CRS, any grade, n (%) 38 (39) Grade 1 47 (48) Grade 2 8 (8) Grade 3 1 (1) Grade 4 7 (7) HLH, any grade, n (%) 0 Grade 1 4 (4) Grade 2 2 (2) Grade 3 1 (1) Grade 4 8 (8) ICANS, any grade, n (%) 5 (5) Grade 1 1 (1) Grade 2 2 (2) Grade 3 Late N - ICAHT Beyond Day 28 ( N=87) 20 (23) ICAHT, any grade, n (%) 15 (17) Grade 1 - 2 5 (6) Grade 3 - 4 All TEAEs occurring in at least 20 patients ( ≥20%) are presented. Grades were determined according to National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0. Grades for CRS and ICANS were determined according to CARTOX criteria ( Neelapu et al, 2018 before protocol v11.0; Neelapu et al, from protocol v11.0 onward ) Late neutropenia - based Immune Effector Cell – Associated Hematotoxicity (N - ICAHT) grade was based on the second - lowest absolute neutrophil count between days 28 - 100 postinfusion and required ≥ 2 neutropenic measurements during this period , including ≥ 1 between days 35 - 60 . Measurements before the day 28 visit were not used for late ICAHT grading but were considered when determining neutropenia onset and duration . Day 28 visits could have occurred ± 3 days before or after day 28 . Assessments were available for n= 87 patients .
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 9 TCR T - cell Activity Across Indications Prof. Dr. med. Antonia Busse , abstract #7231 % activated TCR T cells is evaluated based on surface expression of PD - 1 (% PD - 1 positive TCR T cells ) assessed by flow cytometry . Gynecologic indications include ovarian cancer and uterine cancer ; melanoma includes cutaneous , uveal , mucosal , acral melanoma , and melanoma of unknown primary ; other indications include breast and non - small cell lung cancer. CD, cluster of differentiation ; FP, final product ; IFN - γ, interferon gamma ; PD - 1, programmed cell death protein - 1; TCR, T - cell receptor . Data cutoff: August 7, 2026 Similar PD - 1 Frequency in TCR T cells Over Time Similar Serum IFN - γ Levels Over Time Activated CD4 - CD8+ TCR T cells Activated CD4+CD8+ TCR T cells FP 7 14 60 90 0 20 40 60 80 100 PD-1 Days post-infusion % a c t i v a t e d C D 4 - C D 8 + T C R - T Melanoma SynSar GynOnc Others % activated CD4 - CD8+ TCR T cells FP 7 14 60 90 0 20 40 60 80 100 PD-1 Days post-infusion % a c t i v a t e d C D 4 + C D 8 + T C R - T Melanoma SynSar GynOnc Others % activated CD4+CD8+ TCR T cells Days postinfusion Days postinfusion Days postinfusion Melanoma Synovial sarcoma Other Gynecologic indications
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 10 'DWDFXW RII ; D[LV ,QGLFDWLRQ 3RSXODWLRQ ,0$ &' :DWHUIDOO 2QJRLQJ 3' 6' 35 F35 &5 F&5 %HVWRYHUDOOUHVSRQVH 5(&,67 ,QGLFDWLRQ 5(&,67 %HVW &KDQJHLQ6XPRI/RQJHVW'LDPHWHURI7DUJHW/HVLRQVIURP%DVHOLQH %DVHOLQH * * * Prof. Dr. med. Antonia Busse , abstract #7231 n=2 patients with ovarian cancer and n=1 patient with melanoma died before first postbaseline scan and n=1 additional patient wi th melanoma had a non - evaluable target lesion; these patients are not depicted in the plot but were included in the ORR, cORR and DCR calculation. ORR: according to RECIST 1.1 at any postbaseline scan, PD or death at any prior timepoint; Confirmed ORR for patients with ≥2 postbaseline scans per RECIST 1.1, PD or death at any prior timepoint, those with ongoing unconfirmed PR/CR were excluded. For patients achieving a (c)CR with <100 % c hange from baseline, target lesions were lymph nodes that resolved to <10 mm per RECIST 1.1. BOR, best overall response; (c)CR, (confirmed) complete response; DCR, disease contro l r ate; NSCLC, non - small cell lung cancer; (c)ORR, (confirmed) objective response rate; PD, progressive disease; (c)PR, (confirmed) partial response; SD, stable disease; UNK, unknown. Objective responses across all dose levels and biologically distinct tumor types, including ovarian and uterine cancer, melanoma, and synovial sarcoma 90 N 51% (46/90) ORR 41% (36/87) cORR 82% (74/90) DCR (at week 6) 83% (71/86) Tumor reduction Data cutoff: August 7, 2026 BOR (RECIST 1.1) PD Ongoing response/disease control SD PR cPR CR cCR * Confirmed response based on prior PR that deepened to CR Tumor Reduction Across Dose Levels and Indications During Dose Escalation
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 11 'DWDFXW RII 3DWLHQWVDUHRUGHUHGE\EHVWSHUFHQWDJHFKDQJHZLWKLQHDFKVXEJURXS 6XEJURXSRUGHU 6HOHFWHGVXEJURXSEORFNV :DWHUIDOO3ORW 2QJRLQJ 3' 6' 35 F35 &5 F&5 %HVWRYHUDOOUHVSRQVH 5(&,67 *\Q2QF 0HODQRPD 6\QRYLDO6DUFRPD 2WKHU 'RVH/HYHO 7DUJHW/HVLRQVIURP%DVHOLQH 5(&,67 %HVW &KDQJHLQ6XPRI/RQJHVW'LDPHWHURI %DVHOLQH * * * Tumor Reduction Across Dose Levels During Dose Escalation by Indication Prof. Dr. med. Antonia Busse , abstract #7231 Data cutoff: August 7, 2026 1.95 1.59 1.67 3.55 Median dose [ î 10 9 total TCR T cells] 29 % (2/ 7 ) 67% (8/12) 52 % (23/44) 48 % ( 13 / 27 ) ORR 0 % ( 0 / 6 ) 67% (8/12) 41 % ( 17 / 42 ) 41 % ( 11 / 27 ) cORR 100% (7/7) 100% (12/12) 8 2 % ( 36 / 44 ) 70% (1 9 / 27 ) DCR 86% (6/7) 92% (11/12) 8 8 % ( 37 / 42 ) 68% ( 17 / 25 ) Tumor reduction BOR (RECIST 1.1) PD Ongoing response/disease control SD PR cPR CR cCR * Confirmed response based on prior PR that deepened to CR Gynecologic Indications (n=27) Melanoma (n=44) Synovial Sarcoma (n=12) Other (n=7) n=2 patients with ovarian cancer and n=1 patient with melanoma died before first postbaseline scan and n=1 additional patient wi th melanoma had a non - evaluable target lesion; these patients are not depicted in the plot but were included in the ORR, cORR and DCR calculation. ORR: according to RECIST 1.1 at any postbaseline scan, PD or death at any prior timepoint; Confirmed ORR for patients with ≥2 postbaseline scans per RECIST 1.1, PD or death at any prior timepoint, those with ongoing unconfirmed PR/CR were excluded. For patients achieving a (c)CR with <100 % c hange from baseline, target lesions were lymph nodes that resolved to <10 mm per RECIST 1.1. Gynecologic indications include ovarian cancer and uterine cancer ; melanoma includes cutaneous , uveal , mucosal , acral melanoma , and melanoma of unknown primary ; other indications include breast cancer and non - small cell lung cancer . BOR, best overall response; (c)CR, (confirmed) complete response; DCR, disease control rate; (c)ORR, (confirmed) objective re spo nse rate; PD, progressive disease; (c)PR, (confirmed) partial response; SD, stable disease.
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 12 Changes in Tumor Size Over Time Prof. Dr. med. Antonia Busse , abstract #7231 BOR, best overall response; (c)CR, (confirmed) complete response; mFU , median follow - up; PD, progressive disease; (c)PR, (confirmed) partial response; SD, stable disease Data cutoff: August 7, 2026 3' 3' %DVHOLQH %DVHOLQH 35 35 0RQWKVSRVW7FHOOLQIXVLRQ &KDQJHLQ6XPRI/RQJHVW'LDPHWHURI7DUJHW/HVLRQVIURP%DVHOLQH >@ 3' 6' 35 F35 &5 F&5 %HVWRYHUDOOUHVSRQVH 5(&,67 2QJRLQJ 6SLGHU 3RSXODWLRQ (IILFDF\$QDO\VLV6HW ,0$ &' 0DUNHUV 'RW 'DWDFXW RII All dose levels: Deep and durable responses observed across all indications with ongoing responses beyond 2.5 years ( mFU time of mPFS : 12.8 months ) BOR (RECIST 1.1) PD Ongoing response/disease control SD PR cPR CR cCR Months post T - cell infusion
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 13 Responses of Metastatic Lesions Prof. Dr. med. Antonia Busse , abstract #7231 Each data point represents reduction of a target lesion . Total number of target lesions evaluated : 241. a Best overall response of target lesions not available for n=3 patients . Gynecologic indications include ovarian cancer and uterine cancer ; melanoma includes cutaneous , uveal , mucosal , acral melanoma , and melanoma of unknown primary ; other indications include breast cancer and non - small cell lung cancer . b Other: bone , breast , cervical neck, chest , colon , esophagus , gastric , kidney , pelvis , pleural effusion , skin , vagina , and other investigator specified locations . Data cutoff: August 7, 2026 Melanoma Gynecologic indications Synovial sarcoma Other n=87 a /HVLRQ %HVW &KDQJHIURP%DVHOLQHSHU7DUJHW Q $EGRPHQ 3HULWRQHXP Q /LYHU Q /XQJ Q /\PSKQRGH Q 2WKHU 2WKHUV 6\QRYLDO6DUFRPD *\Q2QF 0HODQRPD ,QGLFDWLRQ %HVW &KDQJHIURP%DVHOLQHSHU7DUJHW/HVLRQ ($6 SDWLHQWV WDUJHWOHVLRQV %R[SORWV\PEROV FRORUHGGRW RQHWDUJHWOHVLRQ FRORULQGLFDWHVPDLQLQGLFDWLRQJURXS ER[ LQWHUTXDUWLOHUDQJH WK WKSHUFHQWLOH OLQHLQVLGHER[ PHGLDQ ZKLVNHUV PRVWH[WUHPHQRQ RXWO\LQJYDOXHV 5HIHUHQFHOLQHV GDVKHGJUH\ DQG VROLGJUH\ 9DOXHVLQSDUHQWKHVHVEHORZHDFKORFDWLRQDUHWKHQXPEHURIWDUJHWOHVLRQVFRQWULEXWLQJWRWKDWER[SORW /RFDWLRQVJURXSHGLQWR2WKHU %RQH %UHDVW &HUYLFDO1HFN &KHVW &RORQ (VRSKDJXV *DVWULF .LGQH\ 2WKHU 3HOYLV 3OHXUDO(IIXVLRQ 6NLQ 9DJLQD %HVWFKDQJHLVWKHPLQLPXPSRVW EDVHOLQHSHUFHQWFKDQJHIURPEDVHOLQHDPRQJ$1/ )/ < DVVHVVPHQWV 'DWDFXW RII ($6SDWLHQWVQRWUHSUHVHQWHGLQWKLVILJXUH 1 1RSRVW EDVHOLQHWDUJHW OHVLRQ6/'DVVHVVPHQW 1RSRVW EDVHOLQHWDUJHW OHVLRQ6/'DVVHVVPHQW 1RSRVW EDVHOLQH WDUJHW OHVLRQ6/'DVVHVVPHQW b
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 14 0RQWKVSRVW7FHOOLQIXVLRQ %DVHOLQH >@ &KDQJHLQ6XPRI/RQJHVW'LDPHWHURI7DUJHW/HVLRQVIURP 3' %DVHOLQH 35 3' 6' 35 F35 &5 F&5 %HVWRYHUDOOUHVSRQVH 5(&,67 2QJRLQJ 6SLGHU 3RSXODWLRQ (IILFDF\$QDO\VLV6HW *\Q2QF%XQGOH ,0$ &' LQ'/ FRUKLJKHU 0DUNHUV 'RW 'DWDFXW RII 'DWDFXW RII ; D[LV ,QGLFDWLRQ 3RSXODWLRQ *\Q2QF%XQGOH ,0$ &' LQ'/ FRUKLJKHU :DWHUIDOO 2QJRLQJ 3' 6' 35 F35 &5 F&5 %HVWRYHUDOOUHVSRQVH 5(&,67 ,QGLFDWLRQ /HVLRQVIURP%DVHOLQH 5(&,67 %HVW &KDQJHLQ6XPRI/RQJHVW'LDPHWHURI7DUJHW %DVHOLQH Antitumor Activity at Higher Doses ≥DL4c in Patients with Gynecologic Indications Prof. Dr. med. Antonia Busse , abstract #7231 n=1 patient with ovarian cancer died prior to first post baseline scan not evaluable for assessment of tumor reduction, not d epi cted in plot but included in ORR, cORR and DCR calculation; ORR: according to RECIST 1.1 at any postbaseline scan, PD or death at any prior timepoint; Confirmed ORR f or patients with ≥2 postbaseline scans per RECIST 1.1, PD or death at any prior timepoint, those with ongoing unconfirmed PR/CR were excluded. Fo r t hose patients achieving a (c)CR with <100% changes from baseline, target lesions were lymph nodes that resolved to <10 mm per RE CIST 1.1. # Ongoing confirmed PR (RECIST 1.1) as of last scan at month 7.5, suspected clinical progression by clinical site at month 6 in discrepancy to RECIST response du e t o tumor marker increase; patient off study at month 8 and receiving further anti - tumor treatment. Initially reported unconfirmed CR according to database entry by site referred to a lesion incorrectly classified as target lesion. Retrospective review determined that patient has no measurable target lesion at base lin e and was therefore removed from efficacy population. BOR, best overall response; (c)CR, (confirmed) complete response; DCR, disease control rate; DL, dose level; (c)ORR, (confirm ed) objective response rate; mDOR , median duration of response; mFU , median follow - up; PD, progressive disease; (c)PR, (confirmed) partial response; SD, stable disease. Data cutoff: August 7, 2026 BOR (RECIST 1.1) PD Ongoing response/disease control SD PR cPR CR cCR * Confirmed response based on prior PR that deepened to CR * Ovarian cancer Uterine cancer Uterine Cancer Ovarian Cancer Gynecologic Indications N=20 2/2 56% (10/18) 60% (12/20) ORR 2/2 50% (9/18) 55% (11/20) cORR 2/2 67% (12/18) 70% (14/20) DCR (at week 6) 2/2 65% (11/17) 68% (13/19) Tumor reduction # Months post T - cell infusion 8.4 (2.1+, 12.2) 6.0 mDOR (range), months mFU #
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 15 .DSODQ 0HLHUHVWLPDWHV FHQVRULQJLQGLFDWHGE\SOXVVLJQV 'DWDFXW RII 3RSXODWLRQ *\Q2QF%XQGOH ,0$ &' LQ'/ FRUKLJKHULQ($6 3URJUHVVLRQ )UHH6XUYLYDO 1XPEHUDWULVN RUKLJKHU *\Q2QF%XQGOH ,0$ &' LQ'/ F 0RQWKV 6XUYLYDOSUREDELOLW\ *\Q2QF%XQGOH ,0$ &' LQ'/ FRUKLJKHU Durability Potential at Higher Doses ≥DL4c in Patients with Gynecologic Indications Prof. Dr. med. Antonia Busse , abstract #7231 Ongoing patients were censored at the data cutoff for PFS and OS; PFS and OS rates were calculated using the Kaplan - Meier method . Gynecologic indications include ovarian cancer and uterine cancer . DL, dose level; mFU , median follow - up; mPFS , median progression - free survival; mOS , median overall survival; NR, not reached. Data cutoff: August 7, 2026 Progression - free survival Overall survival 5.8 (1.1, 14.8) 8.1 mPFS (range), months mFU NR (1.1, 19.9+) 7.8 mOS (range), months mFU Progression - free Survival Probability Overall Survival Probability
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 16 Conclusions Prof. Dr. med. Antonia Busse , abstract #7231 • IMA203CD8 demonstrated a consistent and manageable safety profile in patients with advanced PRAME - positive solid tumors • Antitumor activity observed across multiple tumor types , with 51% ORR and 41% cORR • Deep and durable responses , including multiple complete responses and responses ongoing beyond 2.5 years • Encouraging activity in gynecologic cancers at higher doses , with 60% ORR and 55% cORR • These findings support the clinical proof - of - concept for PRAME - directed TCR T - cell therapy across multiple solid tumors and provide a rationale for continued evaluation of IMA203CD8 (c)ORR, (confirmed) objective response rate; PRAME, preferentially expressed antigen in melanoma; TCR, T - cell receptor. Data cutoff: August 7, 2026
Thank You – Trial Participants & Caregivers Prof. Dr. med. Antonia Busse , abstract #7231 This study was funded by Immatics , Inc. Biostatistical and translational support was provided by Friedrich Vollmer, MSc , and Ana Maia, PhD with Immatics , Inc. Medical writing support was provided by Decera Clinical, funded by Immatics , Inc. Maps generated with ChatGPT - 5.6 Sol, 2026 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
Appendix
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 19 Patient Disposition Prof. Dr. med. Antonia Busse , abstract #7231 a All patients who started lymphodepletion . b All patients who received IMA203CD8 infusion and had ≥1 postbaseline scan, progressive disease or death. DL, dose level; EOT, end of treatment; MUP, melanoma of unknown primary; NSCLC, non - small cell lung cancer . Data cutoff: August 7, 2026 Safety Population a N=98 Efficacy - evaluable Population b n=90 Gynecologic Indications n=27 Melanoma n=44 Synovial Sarcoma n=12 n=1 lymphodepleted, but not infused n=4 pending first postbaseline scan n=1 consent withdrawn before assessment n=1 EOT before first scan n=1 no measurable disease at baseline <DL4c ≥DL4c Ovarian Cancer n=24 Uterine Cancer n=3 Cutaneous melanoma n=22 MUP n=2 n=6 n=18 n=1 n=2 n=15 n=7 n=9 n=6 n=2 n=1 - n=2 n=2 - - n=4 n=2 n=1 Uveal melanoma n=15 Mucosal melanoma n=3 Acral melanoma n=2 Other n=7 Breast cancer n=4 NSCLC n=3 n=11 n=1
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 20 IMA203CD8 TCR T - cell Expansion and Persistence in Multiple Indications Prof. Dr. med. Antonia Busse , abstract #7231 *n indicates the maximum number of patients contributing to an individual timepoint . Sample availability varied across timepoints , with fewer patients contributing data beyond Month 3. Persistence data are presented as median with interquartile range and each point represents a patient. AUC, area under the curve ; Cmax , maximum concentration ; DNA, deoxyribonucleic acid ; gDNA , genomic DNA; TCR, T - cell receptor . Data cutoff: August 7, 2026 1. Kinetics in periphery over time Similar TCR T - cell kinetics between indications with peak occurring mainly at day 3 - 7 and persisting beyond 1 year postinfusion Gynecologic indications (n=29*), melanoma (n=42*), synovial sarcoma (n=12*), other (n=8*) 2. Early expansion Similar TCR T - cell peak level across indications 3. Cumulative exposure and persistence Melanoma Gynecologic indications Synovial sarcoma Other Similar AUC over the first 28, 60, and 90 days
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 21 IMA203CD8 TCR T - cell Persistence in Peripheral Blood in Multiple Indications Prof. Dr. med. Antonia Busse , abstract #7231 Shorter follow - up for gynecologic indications due to later study treatment. TCR, T - cell receptor . Data cutoff: August 7, 2026 Sustained persistence of IMA203CD8 T cells observed across multiple indications, with persistence beyond 2.5 years postinfusion in individual patients Other indications 0 10 20 30 1×10 1 1×10 2 1×10 3 1×10 4 1×10 5 1×10 6 1×10 7 40 60 80 100200 400 600 80010001200 Days post-infusion V e c t o r c o p i e s / µ g D N A Gynecologic indications Melanoma Synovial sarcoma Days postinfusion Days postinfusion Days postinfusion Days postinfusion
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 22 Patient - level Data in Gynecologic Cancers Treated with IMA203CD8 at ≥DL4c in Phase 1 (n=20) Prof. Dr. med. Antonia Busse , abstract #7231 N=20 patients in efficacy population included. BOR, best overall response ; DL, dose level ; cCR , confirmed complete response ; cPR , confirmed partial response ; max , maximum; OC, ovarian cancer ; PARPi , poly (ADP - ribose) polymerase inhibitor ; PFS, progression - free survival ; RECIST, Response Evaluation Criteria in Solid Tumors; TCR, T - cell receptor . Data cutoff: August 7, 2026 Reason for Progression Comment BOR (Max % change of target lesions) BOR DL Total infused dose TCR T cells¹ [ × 10 ⁹ ] Prior treatments Number of prior systemic treatment lines Indication New lesions Response until 6.1 months PFS - 100 CR 5 3.15E+09 Pembrolizumab + Chemotherapy (carboplatin, paclitaxel) 1 Uterine cancer Ongoing response at 10.5 months PFS - 60.8 cCR 6 6.22E+09 Bevacizumab + chemotherapy (carboplatin, paclitaxel) Chemotherapy (carboplatin, doxorubicin) Chemotherapy (carboplatin, gemcitabine) Chemotherapy (paclitaxel) Chemotherapy (docetaxel) 5 Ovarian, fallopian tube, or peritoneal cancer Non - target lesion progression, new lesions Response until 6.0 months PFS - 46.7 cCR 4c 1.43E+09 Chemotherapy (carboplatin, paclitaxel) 1 Ovarian, fallopian tube, or peritoneal cancer Ongoing response at 3.5 months PFS - 100 cPR 7 8.68E+09 Bevacizumab + chemotherapy (carboplatin, paclitaxel) Bevacizumab Bevacizumab + chemotherapy (carboplatin, doxil) PARPi + Mirvetuximab PRT7732 - 01 SGR - 3515 Bevacizumab + Chemotherapy (carboplatin, gemcitabine) 7 Ovarian, fallopian tube, or peritoneal cancer Suspected clinical progression by clinical site in discrepancy to RECIST response due to tumor marker increase Response until 7.4 months PFS - 74.4 cPR 5 2.30E+09 Chemotherapy (carboplatin, paclitaxel) Bevacizumab + chemotherapy (carboplatin, paclitaxel) PARPi + chemotherapy (caelyx, carboplatin) Chemotherapy (carboplatin, cisplatin, gemcitabine) Chemotherapy (paclitaxel) 5 Ovarian, fallopian tube, or peritoneal cancer Target lesion progression Response until 14.8 months PFS - 66.9 cPR 6 7.07E+09 Chemotherapy (carboplatin, paclitaxel) Bevacizumab + chemotherapy (carboplatin, paclitaxel) PARPi + chemotherapy (carboplatin, gemcitabine) Chemotherapy (carboplatin, doxorubicin) 4 Ovarian, fallopian tube, or peritoneal cancer Target lesion progression Response until 5.8 months PFS - 60.9 cPR 7 4.26E+09 Chemotherapy ( carboplatin , paclitaxel ) 1 Ovarian, fallopian tube, or peritoneal cancer Target and non - target progression, new lesions Response until 5.1 months PFS - 43.6 cPR 6 6.59E+09 Chemotherapy (carboplatin, taxol) PARPi Chemotherapy (carboplatin, caelyx) PARPi PARPi Chemotherapy (carboplatin, gemcitabine) 6 Ovarian, fallopian tube, or peritoneal cancer Ongoing response at 7.3 months PFS - 40.2 cPR 6 4.16E+09 Bevacizumab + PARPi + chemotherapy (paclitaxel, docetaxel, carboplatin) Chemotherapy (doxorubicin, carboplatin, gemcitabine) Chemotherapy (carboplatin, cyclophosphamide) 3 Ovarian, fallopian tube, or peritoneal cancer
Content of this presentation is copyright and responsibility of the author. Permission is required for re - use. 23 Patient - level Data in Gynecologic Cancers Treated with IMA203CD8 at ≥DL4c in Phase 1 (n=20) Prof. Dr. med. Antonia Busse , abstract #7231 N=20 patients in efficacy population included . ADC, antibody - drug conjugate ; BOR, best overall response ; DL, dose level ; cCR , confirmed complete response ; cPR , confirmed partial response ; ICI, immune checkpoint inhibitor ; max , maximum; OC, ovarian cancer ; PARPi , poly (ADP - ribose) polymerase inhibitor ; PD, progressive disease ; PFS, progression - free survival ; RECIST, Response Evaluation Criteria in Solid Tumors; SD, stable disease ; TCR, T - cell receptor ; TKI, tyrosine kinase inhibitor . Data cutoff: August 7, 2026 Reason for Progression Comment BOR (Max % change of target lesions) BOR DL Total infused dose TCR - T cells¹ [ × 10 ⁹ ] Prior treatments Number of prior systemic treatment lines Indication Non - target progression Response until 5.8 months PFS - 38.2 cPR 7 12.5E+9 Chemotherapy (carboplatin, taxol) Chemotherapy (carboplatin, gemcitabine) Chemotherapy (mitomycin) Chemotherapy (cisplatin, paclitaxel) 4 Ovarian, fallopian tube, or peritoneal cancer Ongoing response at 8.8 months PFS - 74.1 cPR 7 10.1E+9 Chemotherapy (carboplatin, paclitaxel) Exp. therapy (selinexor) TKI + ICI 3 Uterine cancer Target and Non - target lesion progression Response until 3.0 months PFS - 40 PR 7 11.0E+9 Chemotherapy (carboplatin, paclitaxel) Chemotherapy (carboplatin, gemcitabine) Durvalumab, Olaparib, UV1 injection (therapeutic cancer vaccine) Chemotherapy (paclitaxel) 4 Ovarian, fallopian tube, or peritoneal cancer Not evaluable target and non - target lesions Response until 3.0 months PFS 16.1 SD 4c 2.26E+09 Chemotherapy (carboplatin, taxol) Chemotherapy (carboplatin, paclitaxel) Bevacizumab Exp. therapy (AVB - 001) Bevacizumab + Chemotherapy (carboplatin, gemcitabine) Chemotherapy (carboplatin, gemzar) 6 Ovarian, fallopian tube, or peritoneal cancer Ongoing disease stabilization at 3.5 months PFS 2.0 SD 7 9.22E+09 chemotherapy (carboplatin, paclitaxel) PARPi + Bevacizumab 2 Ovarian, fallopian tube, or peritoneal cancer Target and non - target progression, new lesions Progressive disease at 1.5 months PFS - 40 PD 6 3.55E+09 PARPi + chemotherapy (carboplatin, paclitaxel) Bevacizumab PARPi + chemotherapy (caelyx, carboplatin) Chemotherapy (topotecan) 4 Ovarian, fallopian tube, or peritoneal cancer New lesions Progressive disease at 1.4 months PFS 2.4 PD 6 5.38E+09 Bevacizumab + PARPi + chemotherapy (carboplatin, paclitaxel) Chemotherapy (carboplatin, doxorubicin) Chemotherapy (paclitaxel) 3 Ovarian, fallopian tube, or peritoneal cancer Non - target progression Progressive disease at 1.4 months PFS 2.6 PD 6 6.46E+09 Chemotherapy (carboplatin, paclitaxel) Bevacizumab + PARPi + chemotherapy (carboplatin, doxorubicin) Mirvetuximab Chemotherapy (topotecan) 4 Ovarian, fallopian tube, or peritoneal cancer Target and non - target progression , new lesions Progressive disease at 1.4 months PFS 14.2 PD 5 3.02E+09 PARPi + chemotherapy (carboplatin, taxol) Bevacizumab + chemotherapy (carboplatin, doxorubicin) ADC (PRO1184) 3 Ovarian, fallopian tube, or peritoneal cancer Target lesion progression, new lesions Progressive disease at 1.3 months PFS 21.7 PD 7 6.42E+09 Chemotherapy (carboplatin, paclitaxel) PARPi Chemotherapy (carboplatin, doxorubicin) 3 Ovarian, fallopian tube, or peritoneal cancer Death Progressive disease at 1.1 months n/a PD 5 3.04E+09 Bevacizumab + chemotherapy (carboplatin, paclitaxel) Chemotherapy (caelyx, carboplatin) Chemotherapy (carboplatin, gemcitabine) 3 Ovarian, fallopian tube, or peritoneal cancer