Immatics Initiates Phase 1/2 Clinical Trial to Evaluate PRAME TCR Bispecific IMA402 in Patients with Advanced Solid Tumors TCER IMA402 is the first next-generation, half-life extended TCR Bispecific targeti

Initiates Phase 1/2 Clinical Trial to Evaluate

PRAME TCR Bispecific IMA402 in Patients with Advanced Solid Tumors

and Houston, Texas, August 10, 2023 -

Immatics N.V. (NASDAQ: IMTX, "Immatics"), a clinical-stage biopharmaceutical company

active in the discovery and development of T cell-redirecting cancer immunotherapies, today announced the initiation of a Phase 1/2 clinical

trial with its proprietary Bispecific T cell engaging receptor (TCER ) IMA402. IMA402 is the second product candidate

in Immatics' TCER pipeline of next-generation, half-life extended bispecific molecules to enter clinical development.

It targets an HLA-A*02:01-presented peptide derived from PRAME, a clinically established cancer target frequently expressed in a large

variety of solid tumors.

The Phase 1/2 clinical

trial (NCT05958121) investigates TCER

IMA402 in HLA-A*02:01-positive patients with PRAME-expressing recurrent and/or refractory solid tumors. The dose escalation part

of the study is designed as a basket trial in focus indications to accelerate signal finding. Initial focus indications are cutaneous

and uveal melanoma, ovarian cancer, lung cancer, uterine cancer and synovial sarcoma, among others.

of IMA402 to our clinical pipeline is a truly exciting step and aligns with our strategic goal to harness the full potential of PRAME,

one of the most promising cancer targets in solid tumors. With our half-life extended format, we believe IMA402 has the potential to

be an attractive treatment option by enhancing efficacy, minimizing toxicities, and providing a favorable dosing regimen for cancer patients.,"

said Cedrik Britten, Chief Medical Officer at Immatics. "We are working with urgency to bring IMA402 to a broad patient population

as quickly as possible and look forward to sharing first clinical data in 2024."

of the IMA402 Phase 1/2 trial are to determine the maximum tolerated dose (MTD) and/or the recommended doses for trial extensions, as

well as to characterize safety and

IMA402. Secondary objectives are to evaluate anti-tumor activity and assess pharmacokinetics of IMA402. The Phase 1a dose escalation

will be followed by a Phase 1b dose expansion, with the plan then to initiate a Phase 2 with indication-specific cohorts and/or combination

therapies. Immatics has implemented an adaptive design for the dose escalation with the goal to accelerate the clinical development timeline

of IMA402. Pharmacokinetics data will be assessed throughout the trial and might provide an early opportunity for adjustment of the treatment

interval based on the half-life extended TCER format. The trial is initially planned to be conducted at approximately

15 sites in Europe, with extension into the US at dose expansion stage. The Phase 1a is designed to enroll approximately 45 patients.

The trial initiation

is based on the comprehensive preclinical studies with IMA402 presented at the European Society

for Medical Oncology (ESMO) Congress 2022.

IMA402 is the second Immatics clinical program targeting PRAME, with the first being ACTengine IMA203, a TCR-T cell therapy

that is currently in Phase 1b dose expansion - see recent data release. Both approaches,

ACTengine and TCER , are distinct therapeutic modalities that we believe have the potential to provide

innovative treatment options for a variety of cancer patient populations with different medical needs.

IMA402 is a drug candidate owned by Immatics. IMA402 is Immatics' second TCER molecule from the bispecifics pipeline

and is directed against an HLA-A*02-presented peptide derived from preferentially expressed antigen in melanoma (PRAME), a protein frequently

expressed in a large variety of solid cancers, thereby supporting the program's potential to address a broad cancer patient population.

Immatics' PRAME peptide is present at a high copy number per tumor cell and is homogenously and specifically expressed in tumor

tissue. The peptide has been identified and characterized by Immatics' proprietary mass spectrometry-based target discovery platform,

XPRESIDENT . IMA402 is part of Immatics' strategy to leverage the full clinical potential of targeting PRAME, one

of the most promising targets for TCR-based therapies.

next-generation half-life extended TCER molecules are antibody-like "off-the-shelf" biologics that leverage

the body's immune system by redirecting and activating T cells towards cancer cells expressing a specific tumor target. The design

of the TCER molecules enables the activation of any T cell in the body to attack the tumor, regardless of the T cells'

intrinsic specificity. Immatics proprietary biologics are engineered with two binding regions: a TCR domain and a T cell recruiter domain.

The TCER format is designed to maximize efficacy while minimizing

toxicities in patients.

It contains a high-affinity TCR domain that is designed to bind specifically to the cancer target peptide on the cell surface presented

by an HLA molecule. The antibody-derived, low-affinity T cell recruiter domain is directed against the TCR/CD3 complex and recruits a

patient's T cells to the tumor to attack the cancer cells. With a low-affinity recruiter aiming for optimized biodistribution and

enrichment of the molecule at the tumor site instead of the periphery, TCER are engineered to reduce the occurrence of

immune-related adverse events, such as cytokine release syndrome. In addition, the TCER format consists of an Fc-part

conferring half-life extension, stability, and manufacturability. TCER are "off-the-shelf" biologics and

thus immediately available for patient treatment. They can be distributed through standard pharmaceutical supply chains and provide the

opportunity to reach a large patient population without the need for specialized medical centers.

the discovery of true targets for cancer immunotherapies with the development of the right T cell receptors with the goal of enabling

a robust and specific T cell response against these targets. This deep know-how is the foundation for our pipeline of Adoptive Cell Therapies

and TCR Bispecifics as well as our partnerships with global leaders in the pharmaceutical industry. We are committed to delivering the

power of T cells and to unlocking new avenues for patients in their fight against cancer.

to use its website www.immatics.com as a means of disclosing material non-public information.

statements in this press release may be considered forward-looking statements. Forward-looking statements generally relate to future

events or Immatics' future financial or operating performance. For example, statements concerning the timing of product candidates

and Immatics' focus on partnerships to advance its strategy are forward-looking statements. In some cases, you can identify forward-looking

statements by terminology such as "may", "should", "expect", "intend", "will",

"estimate", "anticipate", "believe", "predict", "potential" or "continue",

or the negatives of these terms or variations of them or similar terminology. Such forward-looking statements are subject to risks, uncertainties,

and other factors which could cause actual results to differ materially from those expressed or implied by such forward looking statements.

These forward-looking statements are based upon estimates and assumptions that, while considered reasonable by Immatics and its management,

are inherently uncertain. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties.

Factors that may cause actual results to differ materially from current

include, but are not limited to, various factors beyond management's control including general economic conditions and other risks, uncertainties

and factors set forth in filings with the SEC. Nothing in this press release should be regarded as a representation by any person that

the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements

will be achieved. You should not place undue reliance on forward-looking statements, which speak only as of the date they are made. Immatics

undertakes no duty to update these forward-looking statements. All the scientific and clinical data presented within this press release

are - by definition prior to completion of the clinical trial and a clinical study report - preliminary in nature and subject

to further quality checks including customary source data verification.

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