On Thursday, Immatics N.V. ( IMTX ) stock is trading lower after the company commenced an underwritten public offering of $150 million.

The company also announced updated Phase 1b data on ACTengine IMA203 TCR-T targeting PRAME in melanoma patients and provided an update on SUPRAME, the upcoming Phase 3 trial to evaluate IMA203 in metastatic melanoma patients.

As of August 23, 2024, 28 heavily pretreated patients with metastatic melanoma were treated with IMA203 at the recommended Phase 2 dose (RP2D, 1 to 10 billion total TCR-T cells) during the Phase 1b dose expansion part of the clinical trial.

IMA203 monotherapy has maintained a favorable tolerability profile with no treatment-related Grade 5 adverse events in the safety population, even at doses up to ~10×10 power 9 TCR-T cells.

The data presented demonstrate a significant positive shift in median progression-free survival (PFS) and median overall survival (OS) between melanoma patients treated during Phase 1a and patients treated in Phase 1b.

In addition, approximately half of all patients in the Phase 1b trial have a deep response (>50% tumor reduction).

This subgroup of patients was observed to have a median PFS of more than one year, while patients with