Immatics Achieves Clinical Proof-of-Concept of its Next-Generation TCR Bispecific (TCER ) Pipeline with Data on IMA402 (PRAME) and IMA401 (MAGEA4/8) and Announces Next Development Steps Company to host conf

Immatics Achieves Clinical Proof-of-Concept of

its Next-Generation TCR Bispecific (TCER ) Pipeline with Data on IMA402 (PRAME) and IMA401 (MAGEA4/8)

and Announces Next Development Steps

Company to host conference call and webcast

today, November 12, at 8:30 am EST/2:30 pm CET

Texas and Tuebingen, Germany, November 12, 2025 - Immatics

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

global leader in precision targeting of PRAME, today announced updated Phase 1a dose escalation data from both product candidates in

its TCR Bispecifics (TCER ) pipeline, IMA402 PRAME Bispecific and IMA401 MAGEA4/8 Bispecific, as well as next steps for

clinical development.

"Our off-the-shelf TCR Bispecifics have a

proprietary next-generation format with half-life extension that is designed to combine optimized tolerability and potent anti-tumor activity

while supporting patient-convenient dosing," said Carsten Reinhardt, M.D., Ph.D., Chief Development Officer at Immatics. "We

have now achieved clinical proof-of-concept for both product candidates and seen their potential to make a meaningful impact on patients

with limited treatment options through deep and durable responses. We look forward to continuing to drive the development of our bispecifics

to advance accessible, innovative therapies that can reach more patients and make a lasting difference in cancer care."

"Today marks the beginning of a new phase

for Immatics, expanding our reach beyond cell therapy and establishing a leading position in the TCR Bispecifics field, with a clear commitment

to advancing the clinical development of our bispecifics pipeline," said Harpreet Singh, Ph.D., CEO and Co-Founder of Immatics.

"Building on these data, we are excited to evaluate our IMA402 PRAME Bispecific now across multiple targeted cancer patient populations

with significant unmet treatment needs and in potentially synergistic combinations. We are especially enthusiastic about the potential

for profound benefit by combining IMA402 with IMA401, our MAGEA4/8 Bispecific, in patients with squamous non-small cell lung cancer, a

large, highly underserved and difficult-to-treat indication."

Carsten Reinhardt, M.D., Ph.D., and Harpreet Singh,

Ph.D., will present the complete TCR Bispecifics dataset and next development steps during a conference call and webcast today, November

12, at 8:30 am EST/2:30 pm CET. The presentation is accessible on the Events & Presentations' page on the Investors &

Media section of the Company's website.

IMA402 PRAME Bispecific Phase 1a Dose Escalation Data Summary

Patient Population: Advanced metastatic

solid tumors with no available treatment options

As of the data cutoff on September 26, 2025, 80

heavily pre-treated patients (median of three prior systemic treatments) with recurrent and/or refractory solid tumors1 were

treated with escalating dose levels of IMA402 monotherapy ranging from 0.02 mg to 30 mg. The safety population includes all 80 patients

treated with IMA402. 29 patients received doses in the recommended Phase 2 dose (RP2D range) (10 to 30 mg) and, thereof, 20 patients

were efficacy-evaluable2, including 14 patients with melanoma (12 cutaneous, 1 uveal, 1 unknown primary), 3 patients with

ovarian carcinoma and 3 patients with other solid cancers3.

Cutaneous melanoma, uveal melanoma, synovial sarcoma, endometrial carcinoma, ovarian cancer, squamous non-small cell lung cancer.

Efficacy-evaluable patients: All patients treated as of June 26, 2025 (who had the opportunity for at least 3 months follow-up or who

discontinued early due to disease progression or death), tested positive or not tested/not evaluable for PRAME and received 4 infusions

as defined per protocol (thereof 3 step doses, currently at 0.03 mg/0.3 mg/6 mg, and 1 target dose).

N=2 endometrioid carcinoma, n=1 synovial sarcoma.

Safety: Treatment with IMA402 showed

favorable tolerability

IMA402 showed favorable tolerability across a wide

dose range in the 80 patients treated. The most frequent treatment-related adverse events (AEs) were expected and transient lymphopenia,

consistent with the mechanism of action, and low-grade cytokine release syndrome (CRS): Grade 1: 33%, Grade 2: 5%, Grade 3: 0%, Grade

4: 1%. No ICANS or IMA402-related Grade 5 events occurred. Tolerability across all doses was consistent with tolerability at the RP2D

Phase 1a dose escalation in the monotherapy setting

has been completed. The maximum tolerated dose (MTD) has not been reached. The provisional RP2D range has been identified at 10 to 30

mg. The Phase 1b dose expansion is ongoing at two distinct doses within the RP2D range, and the evaluation of IMA402 in combination with

an immune checkpoint inhibitor has been initiated.

Anti-tumor Activity and Durability: Deep and durable responses

observed at RP2D range

IMA402 showed a clear dose-response

relationship across three different dose groups.

1 Melanoma includes cutaneous melanoma,

melanoma of unknown primary, uveal melanoma; 2 Other indications include endometrioid carcinoma, synovial sarcoma and one patient with

sqNSCLC at 1.6 mg; BL: baseline; BOR: best overall response; cORR: confirmed objective response rate; cPR: confirmed partial response;

PD: progressive disease; PR: partial response; SD: stable disease; RECIST: response evaluation criteria in solid tumors; RP2D: recommended

Several patients dosed with IMA402 at the RP2D

range were observed to have deep and durable responses. All 6 confirmed objective responses were ongoing as of data cutoff, including

two complete metabolic responses in cutaneous and uveal melanoma, ongoing at 8 and 18 months, respectively, as well as one confirmed partial

response in ovarian carcinoma with -100% reduction in target lesions. All responders with ovarian carcinoma were platinum-resistant, and

all responders with melanoma were immune checkpoint inhibitor-resistant.

BL: baseline; cPR: confirmed partial response;

PD: progressive disease; PR: partial response; SD: stable disease

Deep and durable responses at RP2D range

mDOR: median duration of response; mFU: median

follow-up; DCR: disease control rate

For patients across all indications treated within

the RP2D range early, promising progression-free survival (PFS) and overall survival (OS) were observed:

iRECIST, developed by the RECIST Working Group, adapts the RECIST 1.1 definition for progression of immunotherapies by introducing unconfirmed

(iUPD) and confirmed (iCPD) progression to account for atypical response patterns. Patients with iUPD not confirmed at a subsequent scan

but turning into SD or response are not considered progressive according to iRECIST. PFS (according to RECIST 1.1) and iPFS (according

to iRECIST) are prospectively defined co-secondary endpoints in the IMA402 trial protocol to provide a balanced view of efficacy.

Clinical Development Opportunities for IMA402 PRAME Bispecific

Based on the promising Phase 1a dose escalation

data, Immatics is advancing its IMA402 PRAME Bispecific into Phase 1b dose expansion at two distinct doses to determine the final RP2D,

both as a monotherapy and in combination with an immune checkpoint inhibitor with a focus on melanoma and gynecologic cancers in 2026.

Depending on the outcomes of these Phase 1b cohorts, the Company would seek to convert existing Phase 1b cohorts into Phase 2 trials,

which will then have the potential to become registration-directed. As part of its strategy to maximize the IMA402 opportunity, the Company

is also exploring the option to initiate additional Phase 1b cohorts in 2026 to determine the monotherapy and combination potential of

IMA402 with immune checkpoint inhibitors and standard of care in late as well as earlier treatment lines. As an additional opportunity,

the Company is exploring the potential combination of IMA402 with IMA401 MAGEA4/8 in squamous non-small cell lung cancer (sqNSCLC) and

potentially other solid tumor indications.

IMA401 MAGEA4/8 Bispecific Phase 1a Data Summary

Patient Population: Heavily pre-treated

patients with a broad range of tumor types with no available treatment options

As of the data cutoff on September 26, 2025, 55

heavily pretreated patients (median of four prior systemic treatments) with recurrent and/or refractory solid tumors5 were

treated with escalating dose levels of IMA401 ranging from 0.0066 mg to 2.5 mg with or without an immune checkpoint inhibitor (ICI, pembrolizumab).

The safety population includes all 55 patients treated with IMA401 as a monotherapy (n=46) or in combination with pembrolizumab (n=9).

44 patients were treated with doses from 1 to 2.5 mg, and thereof 38 were evaluable for efficacy6. All efficacy-evaluable

patients treated with IMA401 in combination with pembrolizumab (n=4) had progressed on prior immune checkpoint inhibitor treatments.

Safety: Treatment with IMA401 showed

favorable tolerability at RP2D

Basket trial with >15 different tumor indications.

Efficacy-evaluable patients: All patients treated as of June 26, 2025 (who had the opportunity for at least 3 months follow-up or who

discontinued early due to disease progression or death), and received 4 infusions as defined per protocol (thereof 3 step doses, currently