In the initial TILT-123 monotherapy phase of the trial, disease control is observed in 6/17 (35%) and 10/16 (63%) in CT and PET, respectively. The study demonstrates good tolerability and preliminary efficacy.
Clinical responses were associated with higher serum anti-adenovirus neutralizing antibody titer at baseline and post-treatment. The phase 1b investigating TILT-123, pembrolizumab and PEGylated liposomal doxorubicin in a similar patient population is underway.
TILT-123 therapy induced accumulation of effector lymphocytes in tumors. Peripheral lymphocyte count decrease is a promising biomarker for assessing oncolytic adenovirus therapy response.
Immunohistochemical analysis and single-cell sequencing revealed interesting alterations in injected and noninjected tumors as well as in peripheral blood, during the treatment course, suggesting that TILT-123 facilitated TIL engraftment into the tumor, ultimately leading to a complete response. This case underscores the potential of combined immunotherapeutic approaches as a promising strategy for patients with metastatic mucosal melanoma.