• Proof-of-concept established for LEU011 in the treatment of relapsed/refractory solid tumours
• LEU011 has been well tolerated, with disease control observed in multiple patients at lowest dose evaluated to date
• Enrolment continues in dose-escalation segment of the AERIAL trial with additional data for LEU011 anticipated during the first half of 2026
• Poster presentation of AERIAL trial presented at SITC 2025 Annual Meeting

Leucid Bio ("Leucid" or the "Company"), a privately-held biotechnology company developing innovative Chimeric Antigen Receptor T-cell (CAR-T) therapies using its proprietary lateral CAR platform,  provided an update on the Phase I/IIa  AERIAL trial evaluating the safety and clinical activity of LEU011 in patients with relapsed/refractory solid tumours.

Preliminary data from the ongoing AERIAL trial have established proof-of-concept for LEU011 by demonstrating key biological activity through evidence of encouraging pharmacokinetic (PK) and pharmacodynamic (PD) profiles. In particular, analysis of post-treatment biopsies (as evaluated by ddPCR and RNAScope) has shown tumour infiltration by LEU011 cells.

To date, treatment with LEU011 has been generally well tolerated. In addition, disease control (based on RECIST criteria) has been observed in multiple patients treated with the lowest dose of LEU011. Dose-escalation in the AERIAL trial continues as planned, with additional data from the trial anticipated during the first half of 2026.

Filippo Petti, Chief Executive Officer, Leucid Bio , said: "Although preliminary, we are highly encouraged by these initial data from the AERIAL trial which establish proof-of-concept for LEU011 in the treatment of solid tumours. Furthermore, they highlight LEU011's dual mechanism of action targeting NKG2D stress ligands for tumour recognition and using CXCR2 signalling to enhance T-cell infiltration into the tumour microenvironment."

Dr. John Maher, Chief Scientific Officer, Leucid Bio, added: "Traditionally, CAR-Ts have struggled to deliver robust clinical responses in the treatment of solid tumours. We believe these preliminary data highlight the functional activity of LEU011 in the treatment of solid tumours given its unique mechanism of action. We anticipate that the early signals observed to date for LEU011 will continue to improve as we advance through the dose-escalation segment of the AERIAL trial."

AERIAL is a multi-centre, dose-escalation trial designed to evaluate the safety and clinical activity of LEU011 in patients with relapsed/refractory solid tumours, following a single intravenous dose of LEU011 after preconditioning chemotherapy. Additional information on the AERIAL trial can be found on ClinicalTrials.gov under the identifier NCT06193902.