Immatics (IMTX) Clinical Data Presentation summary

Clinical background and rationale

• Unresectable or metastatic melanoma has high recurrence and limited long-term survival, underscoring the need for new therapies delivering durable responses.

• PRAME is highly expressed in melanoma and many other cancers, making it a promising target for TCR T-cell therapy.

Study design and patient population

• Phase 1 study included dose escalation and expansion in advanced solid tumors expressing PRAME, focusing on HLA-A*02:01-positive patients.

• 74 patients enrolled; 33 with melanoma (14 cutaneous, 16 uveal, 3 other subtypes) in the efficacy population.

• Patients were heavily pretreated, with a median of 2–3 prior systemic therapies and high rates of prior immune checkpoint inhibitor exposure.

Efficacy outcomes

• Confirmed objective response rate (CORR) was 56% (18/32) in metastatic melanoma, with disease control rate of 91%.

• Median duration of response (mDOR) was 12.1 months, median progression-free survival (mPFS) 6.1 months, and median overall survival (mOS) 15.9 months at median follow-up of 13–14 months.

• Deep responses (≥50% tumor reduction) were seen in 42% of patients, correlating with mPFS >1 year.

• Responses were observed in both cutaneous (CORR 50%) and uveal melanoma (CORR 67%).