This clinical trial is focused on studying a type of cancer known as recurrent or metastatic head and neck squamous cell carcinoma. This is a condition where cancer cells form in the tissues of the head and neck and have either returned after treatment or spread to other parts of the body. The study will explore the effectiveness of a new treatment combination involving two medications: zanzalintinib (XL092) and pembrolizumab. Pembrolizumab is already used in cancer treatment, while zanzalintinib is being tested for its potential benefits when used together with pembrolizumab.

The purpose of the study is to compare how well the combination of zanzalintinib and pembrolizumab works against using pembrolizumab alone in treating this type of cancer. Participants in the study will be randomly assigned to receive either the combination treatment or pembrolizumab by itself. Some participants may receive a placebo, which looks like the real medication but does not contain the active drug. The study will involve regular check-ups and monitoring to assess the treatment’s effects and any side effects experienced by the participants.

The study will take place over several months, with participants receiving treatment and being monitored for changes in their condition. The goal is to determine if the combination of zanzalintinib and pembrolizumab can improve outcomes for patients with this type of cancer. Participants will be closely observed by medical professionals throughout the study to ensure their safety and to gather important data on the treatment’s effectiveness.