Adenoid Cystic Carcinoma Metastatic

This is an open-label, investigator-initiated phase II clinical trial designed to evaluate the efficacy and safety of Sacituzumab Tirumotecan (sac-TMT) monotherapy in patients with recurrent or metastatic adenoid cystic carcinoma (ACC) of salivary gland origin and papillary thyroid carcinoma (PTC). A total of 68 patients will be enrolled over in 18-month period, with 34 patients in Cohort A (ACC) and 34 in Cohort B (PTC). All participants will receive sac-TMT at a dose of 4 mg/kg administered intravenously on Days 1 and 15 of each 28-day cycle. The primary endpoint is the objective response rate (ORR), defined as the proportion of patients achieving a complete or partial response as assessed by the site investigators. Secondary endpoints include progression-free survival, overall survival, disease control rate, safety and tolerability, dose intensity, and relative dose intensity.