-- Enrollment in the SUPRAME Phase 3 trial of anzu-cel (anzutresgene 
      autoleucel, IMA203) remains on track to complete the required 
      randomizations by year-end to support final analysis for the primary PFS 
      endpoint; aggregate PFS events (progression or death) occurring more 
      slowly than originally modeled 
 
   -- Company plans to proceed directly to a streamlined final analysis for the 
      primary endpoint, PFS, while strengthening power for the secondary 
      endpoint, OS, to enhance the commercial product profile 
 
   -- SUPRAME topline data disclosure for the final PFS analysis expected in H1 
      2027, followed by BLA submission in 2027 
 
   -- Anzu-cel PRAME Cell Therapy: Updated Phase 1b data at ASCO 2026 continued 
      to show durable anti-tumor activity in metastatic melanoma, with 56% cORR, 
      14.6 months mDOR, 6.1 months mPFS, 16.2 months mOS and a 2-year OS rate 
      of 46%, as well as predictable and manageable tolerability 
 
   -- IMA203CD8 PRAME Cell Therapy: Updated Phase 1 data presented at ASCO 2026 
      demonstrated clinical activity in hard-to-treat gynecologic cancers with 
      a 63% ORR and 50% cORR; updated data across multiple PRAME-positive solid 
      tumors are planned for presentation at the ESMO Congress 2026 
 
   -- IMA402 PRAME Bispecific: Phase 1b data at recommended Phase 2 dose (RP2D) 
      range across multiple cancers planned for presentation at the ESMO 
      Congress 2026 
 
   -- IMA402 PRAME / IMA401 MAGEA4/8 Bispecific Combination: Combination cohort 
      in sqNSCLC enrolling patients with first data expected in 2027 
 
   -- Cash and cash equivalents as well as other financial assets of $448.2 
      million1 (EUR393.4 million) as of June 30, 2026; cash reach projected 
      into 2028 

Houston, Texas and Tuebingen, Germany, August 18, 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 provided a business update and reported financial results for the quarter ended June 30, 2026.

"The Phase 3 SUPRAME trial continues to enroll patients on schedule across sites in North America and Europe. In parallel, the data from the Phase 1b anzu-cel study continue to mature. We are now observing that aggregate progression and death events in the SUPRAME trial are occurring more slowly than originally modeled. Based on these results and FDA feedback, we plan to proceed directly to a streamlined final analysis, while maintaining robust statistical power for the primary PFS endpoint," said Harpreet Singh, Ph.D., Chief Executive Officer and Co-Founder of Immatics. "We believe this approach provides the most efficient path to generating definitive data for regulatory approval and look forward to reporting topline results in the first half of 2027. We continue to build the foundation for the commercial launch to bring anzu-cel to patients who urgently need new treatment options, while advancing the PRAME franchise across our pipeline."

Second Quarter 2026 and Subsequent Company Progress

PRAME Franchise -- Cell Therapy

Anzu-cel (IMA203) PRAME Cell Therapy -- First Market Entry in Advanced Melanoma

Anzu-cel (anzutresgene autoleucel), previously called IMA203, is Immatics' lead PRAME cell therapy and is expected to be the Company's first PRAME therapy to enter the market in advanced melanoma. The current addressable patient population for anzu-cel's first target indications, second-line or later (2L) advanced cutaneous melanoma, as well as metastatic uveal melanoma includes 9,000 patients(2) .

Phase 3 trial, SUPRAME, for anzu-cel (IMA203) in previously treated, advanced melanoma

   -- Immatics' global, randomized, controlled, multi-center Phase 3 clinical 
      trial, SUPRAME, is currently ongoing to evaluate the efficacy, safety and 
      tolerability of anzu-cel PRAME cell therapy as monotherapy vs. 
      investigator's choice in patients with unresectable or metastatic 
      melanoma who have received prior treatment with a PD-1 immune checkpoint 
      inhibitor. Anzu-cel received FDA Orphan Drug Designation and FDA RMAT 
      designation, which includes all benefits of FDA Breakthrough Therapy 
      Designation. 
 
   -- SUPRAME is designed to be an adequate and well-controlled clinical trial 
      to generate the data supporting full regulatory approval of anzu-cel. 
 
   -- The primary endpoint for SUPRAME is blinded independent central review 
      ("BICR")-assessed (RECIST v1.1) progression-free survival $(PFS)$. Key 
      secondary endpoints include overall survival (OS), objective response 
      rate $(ORR)$, safety and patient-reported outcomes measuring quality of 
      life. 
 
   -- Enrollment in SUPRAME, currently ongoing in North America and Europe, 
      remains on track to complete required randomizations by year-end to 
      support final analysis for the primary endpoint. 
 
   -- The aggregate number of PFS events (progressive disease or death) in the 
      SUPRAME trial is occurring more slowly than originally modeled. 
 
   -- As a result, Immatics intends to replace the previously planned interim 
      and final PFS analyses with a single streamlined final analysis, now 
      based on a lower prespecified number of PFS events while maintaining a 
      robust power of 90% for the primary endpoint. 
 
   -- At the same time, Immatics intends to increase the statistical power for 
      the secondary endpoint of OS by enrolling approximately 90 additional 
      patients, bringing the total trial size to approximately 450 patients. 
      This aims to further strengthen the commercial product profile of 
      anzu-cel. The increased number of events needed for the final OS analysis 
      has no impact on the timing of the final PFS analysis. 
 
   -- These planned protocol amendments are based on feedback from the FDA 
      following recent interaction with the agency, with whom Immatics 
      continues to engage. 
 
   -- The Company expects to disclose topline data from the final PFS analysis 
      in the first half of 2027, followed by a BLA submission in 2027. 
 
   -- The Company continues to build the commercial infrastructure for the 
      anticipated launch of anzu-cel after obtaining BLA approval. 

Phase 1/2 trial for anzu-cel (IMA203) in previously treated, metastatic melanoma

   -- Updated Phase 1b clinical data presented at the 2026 ASCO Annual Meeting 
      showed durable anti-tumor activity at longer follow-up in metastatic 
      melanoma, including 56% confirmed ORR, 14.6 months mDOR, 6.1 months mPFS 
      and 16.2 months mOS. The OS rate was 70% at 12 months and 46% at 24 
      months. Anzu-cel maintained a predictable and manageable tolerability 
      profile. Explorative analyses focusing on predictors of durable response 
      have been accepted for presentation at the ESMO Congress 2026. 

Phase 2 cohort for anzu-cel (IMA203) PRAME cell therapy in patients with metastatic uveal melanoma

   -- A Phase 2 cohort to treat approximately 30 additional patients with 
      metastatic uveal melanoma is ongoing and being conducted at select 
      centers in the U.S. and Germany with expertise in uveal melanoma. 
 
   -- Data from the ongoing single-arm Phase 1b trial as well as the Phase 2 
      cohort in metastatic uveal melanoma are intended to support a potential 
      label expansion for anzu-cel following expected initial approval in 
      unresectable or metastatic melanoma. 

IMA203CD8 PRAME Cell Therapy -- Expansion to All Advanced PRAME Cancers

IMA203CD8 is the Company's PRAME cell therapy product candidate being developed with the goal of expanding into all advanced PRAME cancers. Given its enhanced pharmacology profile, the Company intends to pursue the clinical development of this product candidate with a tumor-agnostic approach, including gynecologic cancers (ovarian and uterine).

   -- Updated Phase 1 data in hard-to-treat gynecologic cancers presented at 
      the 2026 ASCO Annual Meeting demonstrated anti-tumor activity at 
      clinically relevant doses, including 63% ORR and 50% confirmed ORR, four 
      complete responses and the longest ongoing response at 12 months. 
      Additional data in synovial sarcoma showed a 67% ORR and 64% confirmed 
      ORR, including one complete response and ongoing responses for up to 
      approximately three years. IMA203CD8 demonstrated a manageable and 
      consistent tolerability profile across patient populations. 
 
   -- The clinical activity observed to date across tumor types (ovarian 
      carcinoma, uterine cancer, melanoma, synovial sarcoma) with distinct 
      biology and differing levels of PRAME expression supports the broad 
      applicability of IMA203CD8 across solid tumors. 
 
   -- The Company completed Phase 1a dose escalation as planned in mid-2026. 
 
   -- Updated Phase 1 data from IMA203CD8 across multiple PRAME-positive solid 
      tumors will be presented at ESMO Congress 2026. 
 
   -- In addition to its broad expression across more than 50 adult cancer 
      types, PRAME is highly prevalent in multiple pediatric cancers. A case 
      report published in the New England Journal of Medicine3 highlights the 
      therapeutic potential of PRAME TCR T-cell therapy in pediatric patients 
      with solid tumors. Immatics intends to support further clinical 
      evaluation in this population by manufacturing and supplying IMA203CD8 
      PRAME TCR T-cell therapy for the planned investigator-initiated Phase 1/2 
      PRAMEtime trial at Hopp Children's Cancer Center Heidelberg (KiTZ), 
      Germany. 

PRAME Franchise - Bispecifics

IMA402 PRAME Bispecific -- Expansion to Earlier-Line PRAME Cancers