Immunocore Holdings Plc (NASDAQ: IMCR) has released the latest phase 1 data on brenetafusp (IMC-F106C), an off-the-shelf IMTAC targeting PRAME for the treatment of late-line cutaneous melanoma. As of March 18, 2024, 47 patients received brenetafusp monotherapy at clinically active target dose levels. All patients had received prior immune checkpoint inhibitors, with 100% receiving anti-PD1 and 81% receiving anti-CTLA4. Notably, 42% of ctdna-evaluable, PRAME-positive monotherapy patients had a molecular response, and a trend for longer progression-free survival (PFS) and overall survival (OS) was observed in molecular responders.
In addition, 9 cutaneous melanoma patients received brenetafusp in combination with an anti-PD1 (pembrolizumab). Of the 7 patients evaluable for efficacy in combination, 4 achieved disease control, with 3 of the 4 ctdna-evaluable patients showing a molecular response.
Peripheral blood T cell fitness was associated with increased brenetafusp clinical activity, with patients displaying higher T cell fitness gene signature levels having higher clinical benefit, including a median PFS of 6 months and a disease control rate (DCR) of 69%.
The Phase 1 trial data also revealed that patients with PRAME-positive tumors had a higher disease control rate (DCR) of 58% and a median PFS of 4.2 months, compared to PRAME-negative patients with a DCR of 56% and a median PFS of 2.1 months.
Immunocore is currently screening patients in a Phase 3 clinical trial (PRISM-MEL-301) of brenetafusp with nivolumab in first-line advanced cutaneous melanoma, with a primary endpoint of PFS. The company is enrolling HLA-A*02:01-positive, first-line advanced cutaneous melanoma patients, randomizing them to brenetafusp + nivolumab versus a control arm of either nivolumab or nivolumab + relatlimab, depending on the country of enrollment.
The company will host a live webcast and conference call to discuss the phase 1 PRAME expansion data and the phase 3 registrational trial in cutaneous melanoma. The presentation of the advanced cutaneous melanoma data from the ongoing Phase 1/2 trial of brenetafusp will be accessible in the ‘Events & Presentations’ section of the company’s website.
Today the company's shares have moved 4.9% to a price of $48.98. For the full picture, make sure to review Immunocore's 8-K report.