Immatics N.V. (IMTX) saw its stock take a dip on Thursday after announcing a $150 million public offering. However, the company also unveiled positive Phase 1b data for its IMA203 TCR-T therapy, which targets PRAME in melanoma patients. This news highlighted the potential for a significant breakthrough in the treatment of this aggressive cancer.
The Phase 1b data demonstrated a substantial improvement in median progression-free survival (PFS) and median overall survival (OS) for melanoma patients treated with IMA203 compared to those who received treatment during Phase 1a. Notably, approximately half of the patients in the Phase 1b trial exhibited a deep response, with a tumor reduction exceeding 50%. This subgroup of patients experienced a median PFS exceeding one year. Even patients with less than 50% tumor reduction, including those with tumor size increases, showed more than twice the median PFS compared to those treated with suboptimal doses during dose escalation.
The positive findings of the trial were further strengthened by translational data, which indicated that IMA203 T cells rapidly engrafted in all patients after a single dose and exhibited persistence for over two years.
This encouraging data led Immatics to initiate a Phase 3 trial for IMA203 targeting PRAME in 360 HLA-A*02:01-positive patients with metastatic melanoma. The trial is scheduled to commence in December 2024, with patient enrollment projected to be completed by 2026. A pre-specified interim analysis is planned for early 2026, and the company aims to submit an FDA marketing application for full approval in early 2027.
Despite the optimistic news surrounding the clinical trial, IMTX stock faced a decline of 11.1% on Thursday, closing at $9.841. This likely reflects investor concerns about the public offering, which might dilute existing shareholder value. However, the positive data from the Phase 1b trial suggests a promising future for IMA203 as a potentially impactful treatment for melanoma patients.
