Business Context and Reporting Period
This Form 6-K filing by Immatics N.V. is dated June 1, 2026. The report details updated clinical data releases for three key product candidates: IMA203CD8 (PRAME TCR T-cell therapy), IMA401 (MAGEA4/8-targeted TCR bispecific), and anzu-cel (PRAME TCR T-cell therapy for melanoma). The data cutoffs for the clinical trials range from September 24, 2025, to March 30, 2026.
Key Clinical Metrics and Financial Status
Financial Metrics: The filing text does not provide specific financial values for revenue, profit, cash flow, margins, debt, or liquidity. This report focuses exclusively on clinical trial progress.
Clinical Metrics Summary:
- IMA203CD8 (Gynecologic Cancers): In 19 efficacy-evaluable patients at clinically relevant doses, the confirmed Objective Response Rate (cORR) was 50% (9/18). Two confirmed complete responses were observed, with 89% of confirmed responses ongoing. Median Duration of Response (mDOR) was not reached.
- IMA203CD8 (Synovial Sarcoma): In 12 patients, cORR was 64% (7/11). Four responses were ongoing, including one confirmed complete response lasting approximately 3 years. mDOR was 14.8 months.
- IMA401 (Solid Tumors): In 14 head and neck cancer patients at Recommended Phase 2 Dose (RP2D), cORR was 29% (4/14) with a Disease Control Rate (DCR) of 64%. In melanoma patients (n=6), cORR was 33% (2/6).
- Anzu-cel (Melanoma): In 33 patients with advanced melanoma, cORR was 56% (18/32). Subgroup cORR was 50% for cutaneous melanoma and 67% for uveal melanoma. Median Overall Survival (mOS) was 16.2 months across all melanoma types.
Material Changes and Safety Profile
The filing reports continued clinical activity across heavily pretreated patient populations with no Grade 5 adverse events attributed to the therapies in the reported cohorts.
- Safety: All three candidates demonstrated manageable tolerability. The most frequent adverse events were cytopenias and Cytokine Release Syndrome (CRS), consistent with the mechanism of action. No Grade 5 events were observed for IMA203CD8 or anzu-cel. For IMA401, five Dose-Limiting Toxicities (DLTs) occurred, but none at RP2D with dexamethasone premedication.
- Dose Determination: The Maximum Tolerated Dose (MTD) was not reached for IMA203CD8 or IMA401. The Company expects to determine the Recommended Phase 2 Dose (RP2D) for IMA203CD8 in gynecologic cancers in 2026.
- Combination Therapy: IMA401 showed favorable tolerability in combination with pembrolizumab, with no overlapping or additive toxicity observed compared to monotherapy.
Guidance, Outlook, and Risks
Outlook and Next Steps:
- IMA203CD8: The Company plans to present updated data, including durability follow-up at RP2D, in the second half of 2026. Clinical evaluation is expanding into additional PRAME-positive solid tumor indications.
- Anzu-cel: The ongoing Phase 3 SUPRAME trial is evaluating anzu-cel as a monotherapy versus investigator's choice in cutaneous melanoma. A Phase 2 cohort in metastatic uveal melanoma is ongoing to support potential label expansion.
- IMA401: Preclinical data suggests a combination of IMA401 and IMA402 could boost anti-tumor activity in patients positive for both MAGEA4/8 and PRAME targets.
Risks and Contingencies:
- The filing contains forward-looking statements regarding trial timing, outcomes, and regulatory filings, which are subject to risks and uncertainties.
- All scientific and clinical data presented are preliminary and subject to further quality checks and source data verification.
- Actual results may differ materially from expectations due to factors beyond management's control, including general economic conditions and clinical trial variability.
Investor Verification Checklist
- Verify the specific data cutoff dates for each trial (ranging from Sept 2025 to March 2026) to ensure current relevance.
- Confirm the definition of "clinically relevant doses" for IMA203CD8 in gynecologic cancers (defined as $\ge$ DL4c).
- Review the full safety tables for IMA401 combination therapy to assess long-term toxicity profiles with pembrolizumab.
- Monitor the timeline for the Phase 3 SUPRAME trial readout for anzu-cel in cutaneous melanoma.
- Check subsequent filings for the determination of the RP2D for IMA203CD8 in gynecologic cancers, expected in 2026.