This phase I trial investigated subcutaneous tislelizumab injections in treatment-naive patients with advanced or metastatic non-small cell lung cancer. The study involved 39 participants in part 1 and 22 in part 2. Researchers compared subcutaneous injections given in the abdomen or thigh against standard intravenous tislelizumab.
The primary goal was to measure drug levels in the blood. Results showed that trough concentrations were higher with subcutaneous injections than with intravenous ones. Specifically, thigh injections reached a geometric mean of 23.1 micrograms per milliliter, while abdomen injections reached 19.5 micrograms per milliliter. Intravenous administration resulted in a geometric mean of 14.8 micrograms per milliliter. Bioavailability was 85.6% for thigh injections and 72.4% for abdomen injections.
Secondary outcomes included safety and early signs of efficacy. The overall response rate was 44.4%. Median duration of response and median progression-free survival were not reached during the study period. No new safety signals or injection-site reactions were reported, and tolerability was consistent with previous studies. However, this is a small, early-phase study, so efficacy results are preliminary and should not be overinterpreted.