This study is testing if a medicine called pembrolizumab, used with or without another drug called sacituzumab tirumotecan, helps people with a type of lung cancer (metastatic squamous non-small cell lung cancer, or NSCLC) live longer. Pembrolizumab is a type of immunotherapy, which means it helps your immune system fight cancer. Sacituzumab tirumotecan is a drug that might help keep cancer from growing. The study starts with everyone getting pembrolizumab and chemotherapy (carboplatin and paclitaxel or nab-paclitaxel). After that, participants are randomly chosen to continue with just pembrolizumab or with both pembrolizumab and sacituzumab tirumotecan.

• The study lasts several months, with regular visits needed.
• Participants might receive additional treatments that could have side effects.
• There may be risks involved, such as side effects from the drugs.

Before joining, participants need to meet certain health criteria and should not have had certain previous treatments. People with other serious health problems or different types of cancer cannot join.