Sacituzumab Tirumotecan in Participants With Locally Advanced or Metastatic Thymic Carcinoma

The goal of this clinical trial is to learn if drug Sac-TMT works to treat Thymic Carcinoma. It will also learn about the safety of Sac-TMT. The main questions it aims to answer are: * How effective is drug Sac-TMT in treating Thymic Carcinoma? * What adverse events (AEs) do participants have when taking drug Sac-TMT? Participants will: * Progress after at least one platinum-based chemotherapy treatment. * Take drug Sac-TMT every 2 weeks. * Take tumor response assessments every 6 weeks.

Inclusion Criteria: * Males or females aged ≥ 18 to ≤ 75 years at the time of signing the Informed Consent Form; * Participants with histologically or cytologically confirmed thymic carcinoma, and locally advanced or metastatic thymic carcinoma who are not suitable for curative intent therapy; * Participants with advanced thymic carcinoma who have progressed after at least one prior platinum-based chemotherapy; * Able to provide a tumor tissue sample at the time of or after the diagnosis of locally advanced or metastatic tumor; * At least one measurable target lesion that has not received radiotherapy according to RECIST v1.1; * ECOG performance status score of 0 or 1; * Expected survival ≥ 12 weeks; * Adequate organ and bone marrow function. Exclusion Criteria: * Participants with histologically or cytologically confirmed thymoma or thymic neuroendocrine tumor; * Participants with known metastases to meninges, brainstem metastases, spinal cord metastases and/or compression, active or untreated brain metastases; * Participants with other malignant tumors within 3 years prior to the first dose; * Presence of any of conditions or risk factors related to cardiovascular and cerebrovascular diseases; * Uncontrolled systemic disease as judged by the investigator; * History of interstitial lung disease/noninfectious pneumonitis requiring steroid therapy; * Clinically severe pulmonary impairment due to lung disorder; * Presence of active hepatitis B or hepatitis C; * Known active tuberculosis; * Known hypersensitivity to the study drug or any of its components.