Immatics Presents Clinical Proof-of-Concept Data from Ongoing Phase 1 Dose Escalation Trial with TCR Bispecific Molecule TCER IMA401 Targeting MAGEA4/8 at ESMO 2024 and Provides Development Update TCER IMA4

Immatics Presents Clinical Proof-of-Concept Data

Phase 1 Dose Escalation Trial with TCR Bispecific Molecule TCER IMA401

Targeting MAGEA4/8 at ESMO 2024 and Provides

Texas and Tuebingen, Germany, September 16, 2024 - Immatics N.V. (NASDAQ: IMTX, "Immatics" or the "Company"),

a clinical-stage biopharmaceutical company active in the discovery and development of T cell-redirecting cancer immunotherapies, today

in this analysis had received IMA401 infusions 1 mg and showed MAGEA4/8 target expression higher than the MAGEA4/8high

qPCR threshold (n=17).

proof-of-concept clinical data for the first candidate

of its next-generation, half-life extended TCR Bispecifics platform, TCER IMA401 (MAGEA4/8), during an oral presentation

at the European Society for Medical Oncology (ESMO) Congress 2024.

Initial data from the IMA401 Phase 1a first-in-human

dose escalation basket trial in a broad range of heavily pretreated patients with recurrent and/or refractory solid tumors showed initial

anti-tumor activity, durable objective responses, including confirmed responses ongoing at 13+ months,

and a manageable tolerability profile.

The data from the ongoing Phase 1 trial will be

presented today by Martin Wermke, M.D. during the Investigational Immunotherapy oral presentation session at the ESMO Congress 2024.

The IMA401 data slides are accessible in the Events & Presentations' section

of the Investor & Media section of the Company's website.

"Today marks the achievement of a major milestone

for Immatics as the data presented confirm clinical proof-of-concept for our proprietary TCER therapeutic approach and

IMA401, our next-generation, half-life extended TCR-based bispecific targeting a novel tumor-specific peptide derived from MAGEA4/8. We

are very pleased to observe initial anti-tumor activity, including durable objective responses, during dose escalation in a heavily pre-treated

patient population and across several solid tumor types," said Carsten Reinhardt, M.D., Ph.D., Chief Development Officer at Immatics.

"As the clinical trial progresses, our goal will be to further leverage the potential of this product candidate by focusing on the

enrollment of indications with high MAGEA4/8 target expression, such as lung and head and neck cancer patients, seeking to optimize the

treatment schedule and also exploring the incremental clinical benefit available to patients through combining IMA401 with a checkpoint

collaboration with Bristol Myers Squibb (NYSE:BMY) for the co-development of IMA401 has ended

due to ongoing portfolio prioritization efforts within Bristol Myers Squibb. The existing collaboration and license agreement signed

in December 2021 will terminate effective December 12, 2024. Thereafter, all IMA401 development and commercialization rights will be reverted

to Immatics. Immatics is not obligated to refund Bristol Myers Squibb any part of the $150 million upfront received under the collaboration

and is not required to make any future milestone payments to Bristol Myers Squibb; the parties will engage in a wind-down period as stipulated

under the collaboration agreement.

Based on the terms of the agreement with Bristol

Myers Squibb, Immatics has been responsible for conducting the ongoing Phase 1 clinical trial. Immatics intends to advance IMA401 further

through clinical development. The next data update is expected in 2025.

"Building on the initial anti-tumor activity

observed in heavily pretreated patients with solid tumors, we are delighted to bring this highly promising drug candidate back into our

pipeline as a wholly owned asset," said Harpreet Singh, Ph.D., CEO and Co-Founder of Immatics. "We see tremendous potential

in going after cancers that express MAGEA4 and MAGEA8, complementing our PRAME franchise and strengthening our ability to deliver a meaningful

impact on the lives of solid cancer patients."

Key Clinical Findings from TCER IMA401 Monotherapy

baseline characteristics: Heavily pretreated patients with a broad range of tumor types

cut-off on July 23, 2024, 35 heavily pretreated patients with recurrent and/or refractory solid tumors have been treated with IMA401 monotherapy

across nine escalating dose levels. The treated patient population is composed of patients with 16 different solid tumor indications who

are both HLA-A*02:01 and MAGEA4/8-positive, had received a median of four and up to eight lines of prior systemic treatments and the majority

have an ECOG performance status of 1. The safety population includes all

35 patients treated with IMA401. 29 patients were evaluable for efficacy analysis, of which 17 patients were treated at relevant dose

Safety: Treatment with IMA401 demonstrates a manageable tolerability

IMA401 demonstrated an overall manageable tolerability

profile in the 35 patients treated. The most frequent treatment-related adverse events (AEs) were transient lymphopenia and mild to moderate

cytokine release syndrome (CRS) with the majority of CRS occurring at the first dose. Both AEs are consistent with the proposed mechanism

of action and reported for other bispecific T cell engagers. Neutropenia was also observed at high dose levels and occurred mostly at

the initial target dose in patients with and without dexamethasone pre-medication. High-grade neutropenia was fully resolved in all cases

Dose escalation for the trial is ongoing and the

maximum tolerated dose has not yet been determined.

Pharmacokinetics: Next-generation TCER

format shows extended half-life in solid cancer patients

IMA401 demonstrated an "antibody-like"

median half-life of over two weeks (16.9 days). This supported the switch to q2w dosing (once every two weeks) during dose escalation.

In addition, the data support pursuing increased

dosing intervals of up to q4w (once every four weeks), which could further offer an ideal dosing interval for potential combination with

checkpoint inhibitors.

Initial anti-tumor activity: IMA401 demonstrates

initial anti-tumor activity in multiple tumor types

of data cut-off on July 23, 2024, three of four confirmed responses were ongoing at 13+, 8+ and 3+ months. Deep responses (tumor shrinkage

of 50%) were observed in four patients (head and neck squamous cell carcinoma, neuroendocrine tumor of unknown primary, cutaneous

and mucosal melanoma).

obtained also indicate that objective responses are associated with MAGEA4/8 target expression level.

in this analysis had received IMA401 infusions 1 mg and showed MAGEA4/8 target expression higher than the MAGEA4/8high

qPCR threshold (n=17).

TCER IMA401 is Immatics'

most advanced TCER molecule from the Bispecifics pipeline that targets an HLA-A*02-presented (human leukocyte antigen)

peptide derived from two different cancer-associated proteins, melanoma-associated antigen 4 and/or 8 ("MAGEA4/8"). The MAGEA4/8

peptide has been identified and validated by Immatics' proprietary mass spectrometry-based target discovery platform XPRESIDENT

and is presented at a 5-fold higher copy number per tumor cell than the MAGEA4 peptide targeted in other clinical trials.

TCER IMA401 is currently being

evaluated in a Phase 1 basket trial in patients with solid tumors expressing MAGEA4/8. The MAGEA4/8 peptide has a high prevalence in several

solid tumor indications such as head and neck squamous cell carcinoma (HNSCC), small cell lung cancer (SCLC), as well as melanoma, sarcoma

subtypes and other solid cancer types.

Immatics combines 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.

Immatics intends to use

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

Forward-Looking Statements

Certain statements in

this press release may be considered forward-looking statements. Forward-looking statements generally relate to future events or the Company's

future financial or operating performance. For example, statements concerning timing of data read-outs for product candidates, the timing,

outcome and design of clinical trials, the nature of clinical trials (including whether such clinical trials will be registration-enabling),

the timing of IND or CTA filing for pre-clinical stage product candidates, estimated market opportunities of product candidates, the Company's

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

statements by terminology such as "may", "should", "expect", "plan", "target",

"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