Enrollment Milestone

Immatics' SUPRAME trial advances toward 2026 enrollment completion in melanoma

The only Phase 3 program targeting PRAME in checkpoint-refractory melanoma is recruiting toward a 2026 enrollment finish, setting up a progression-free survival readout against investigator's-choice therapy.

By AppliedXLJuly 13, 2026Trial NCT06743126

Executive Summary

Immatics is recruiting toward a 2026 enrollment finish for the pivotal trial testing whether its lead cell therapy can beat standard second-line treatment in melanoma patients who have already failed checkpoint inhibitors.
No other Phase 3 program anywhere targets the same tumor antigen in this population, making this trial the sole test of the mechanism at a registrational scale.
The trial's enrollment target, endpoint, and comparator arm have all stayed unchanged since the study opened, a sign of operational stability rather than concern.
The randomized progression-free survival comparison against active therapy, not the enrollment pace, is the result that will determine whether the mechanism's early single-arm signal holds up under controlled conditions.

The trial

SUPRAME (NCT06743126) is a randomized, controlled Phase 3 trial comparing IMA203, Immatics' ACTengine TCR-T cell therapy (engineered T-cell receptor therapy) directed at the PRAME tumor antigen, against investigator's choice of approved treatments in patients with unresectable or metastatic cutaneous melanoma who have already progressed on a checkpoint inhibitor. The comparator arm includes nivolumab/relatlimab, nivolumab, ipilimumab, pembrolizumab, lifileucel, or chemotherapy. The trial targets 360 patients across the United States, Germany, the United Kingdom, France, the Netherlands, and Canada, restricted to HLA-A*02:01-positive patients with ECOG performance status 0-1. Its status moved from Not yet recruiting to Recruiting in January 2025, and the enrollment target has held at 360 since the trial's registration, with no amendment to the primary endpoint. NCT06743126

Probability of Success

Endpoint Met96%

Completes23%

Clinical Significance55%

Regulatory80%

The endpoint bar

The registered primary endpoint is progression-free survival assessed by blinded independent central review (BICR), a randomized comparison against active therapy rather than a single-arm response measure. Secondary endpoints include overall survival, objective response rate, and treatment-emergent adverse events, giving the trial multiple axes to characterize both efficacy and tolerability once it reads out. Immatics' own reporting frames the trial as heading toward a 2026 enrollment completion, with the SUPRAME program expected to trigger pre-specified interim and final analyses that same year, according to the company's own guidance. The registry's own primary completion date is listed as January 2028, later than the sponsor's stated enrollment-completion window, a gap that reflects the distinction between finishing enrollment and reaching the events needed for the survival analysis. NCT06743126+1

Why this trial is the only one

Among industry trials targeting PRAME, only IMA203 has reached Phase 3; the seven other PRAME-targeted programs identified, including Immunocore's brenetafusp and earlier-stage assets from Outpace Bio, Neowise Biotechnology, and Immunocore's own IMC-P115C, remain in Phase 1 or Phase 2. Immunocore's brenetafusp has reached its own Phase 3 trial in previously untreated melanoma, but that program targets first-line patients rather than the checkpoint-refractory, second-line-plus population SUPRAME enrolls. Within cutaneous melanoma specifically, no other trial shares both the PRAME target and this refractory population at a registrational scale, making SUPRAME the sole test of whether TCR-T cell therapy can outperform standard second-line options here.

The prior signal

Immatics has reported that its earlier single-arm Phase 1b trial of IMA203 in advanced melanoma showed a confirmed objective response rate of 54%, a median duration of response of 12.1 months, and median progression-free survival of 6 months, with overall survival not reached at a median follow-up of 8.6 months. That data came from an uncontrolled, single-arm design; SUPRAME's randomized structure against active comparator therapy is the first test of whether that response signal converts into a progression-free survival advantage under controlled conditions. Immatics+1

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