This phase I trial tests the safety and effectiveness of indium In 111 panitumumab (111In-panitumumab) for identifying the first lymph nodes to which cancer has spread from the primary tumor (sentinel lymph nodes) in patients with head and neck squamous cell carcinoma (HNSCC) undergoing surgery. The most important factor for survival for many cancer types is the presence of cancer that has spread to the lymph nodes (metastasis). Lymph node metastases in patients with head and neck cancer reduce the 5-year survival by half. Sometimes, the disease is too small to be found on clinical and imaging exams before surgery. 111In-panitumumab is in a class of medications called radioimmunoconjugates. It is composed of a radioactive substance (indium In 111) linked to a monoclonal antibody (panitumumab). Panitumumab binds to EGFR receptors, a receptor that is over-expressed on the surface of many tumor cells and plays a role in tumor cell growth. Once 111In-panitumumab binds to tumor cells, it is able to be seen using an imaging technique called single photon emission computed tomography/computed tomography (SPECT/CT). SPECT/CT can be used to make detailed pictures of the inside of the body and to visualize areas where the radioactive drug has been taken up by the cells. Using 111In-panitumumab with SPECT/CT imaging may improve identification of sentinel lymph nodes in patients with head and neck squamous cell cancer undergoing surgery.

This phase I trial tests the safety, side effects, and best dose of eltanexor in combination with venetoclax for the treatment of patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) that has come back after a period of improvement (relapsed) or that has not responded to previous treatment (refractory). Eltanexor works by trapping "tumor suppressing proteins" within the cell, thus causing the cancer cells to die or stop growing. Venetoclax is in a class of medications called B-cell lymphoma-2 (BCL-2) inhibitors. It may stop the growth of cancer cells by blocking Bcl-2, a protein needed for cancer cell survival. Giving eltanexor together with venetoclax may be safe, tolerable and/or effective in treating patients with relapsed or refractory MDS or AML.

The goal of this clinical trial is to evaluate the safety and efficacy of TOS-358 in women with HR+ HER2- metastatic breast cancer whose tumors have a mutation in PIK3CA and who meet all other study enrollment criteria. The main questions it aims to answer are:

1. Phase 1a: what is the maximum tolerated dose and recommended dose for phase 2?
2. Phase 1a: how safe and tolerable is TOS-358 at different dose levels when taken orally once or twice per day?
3. Phase 1b: how safe and effective is TOS-358 when given with standard of care medicines for HR+HER2- metastatic breast cancer (fulvestrant and CDK4/6i)