To Evaluate the Efficacy and Safety of Tislelizumab in Combination With Lenvatinib in Participants With Selected Solid Tumors

Key Inclusion Criteria:

1. Participants had signed an informed consent form and were able to comply with all study requirements.
2. Participants had a histologically and/or cytologically confirmed diagnosis of advanced solid tumors, which included one of the following types:

   * Non-Small Cell Lung Cancer (NSCLC)
   * Squamous Cell Carcinoma of the Head and Neck (SCCHN)
   * Gastric Cancer (GC)
   * Urothelial Carcinoma (UC)
   * Renal Cell Carcinoma (RCC)
3. Participants had at least one measurable lesion as defined by the Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1.
4. Tumor tissue samples (approximately 10 unstained slides) were provided for central laboratory assessment of programmed death-ligand 1 (PD-L1) expression in the NSCLC cohort during the screening period. These samples were also used for retrospective exploratory biomarker analyses related to treatment response and resistance across the NSCLC, SCCHN, UC, or Gastric Cancer (GC) cohorts, in a central or designated test laboratory approved by BeiGene.
5. Participants had an Eastern Cooperative Oncology Group (ECOG) performance of 0 or 1

Key Exclusion Criteria:

1. For participants in the NSCLC cohort, those with active leptomeningeal disease or uncontrolled, untreated brain metastases were excluded. In cohorts other than NSCLC, any participant with known leptomeningeal disease or brain metastases was excluded.
2. Participants who had received prior therapy with lenvatinib, or with antibodies targeting programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), programmed death-ligand 2 (PD-L2), or any other agents specifically targeting T-cell costimulatory or immune checkpoint pathways, were excluded.
3. Participants with a history of interstitial lung disease, non-infectious pneumonitis, or any uncontrolled pulmonary conditions (including but not limited to pulmonary fibrosis or acute lung diseases) were excluded.
4. Participants who were unable to swallow capsules, or who had diseases or previous procedures that significantly affected gastrointestinal function such as malabsorption syndrome, surgical resection of the stomach or small bowel, bariatric surgery, symptomatic inflammatory bowel disease, or partial/complete bowel obstruction were excluded.
5. Participants who had experienced clinically significant bleeding (classified as Grade 2 or higher according to the Common Terminology Criteria for Adverse Events \[CTCAE\]) within 21 days prior to the first dose were excluded.

Note: Additional protocol-defined inclusion and exclusion criteria may have applied.