Optimizing Ancillary Therapies With Immune Checkpoint Inhibitors for Solid Tumors (OAT ICI)

Inclusion Criteria: * Solid tumor patients with measurable disease. Including patients with early stage and advanced stage cancer. * Patients who are to get neoadjuvant or induction therapy prior to planned surgery or radiation are included if definitive therapy is planned to occur at least 18 weeks after ICI initiation. * Treatment plan includes an immune checkpoint inhibitor (PD1 or PD-L1 inhibitor) as standard of care. Standard of care will be determined by referring to the NCCN guidelines. For rare situations where a disease is not found in the NCCN guideline, the treatment must be considered standard of care at the MCC. * ECOG Performance Status 0-3. * Life expectancy of at least 3 months. * Adequate hematologic, renal and hepatic function based on institutional standards. * Must be willing to stop/not start daily acetaminophen during the study period * Must be willing to stop/not start THC-containing agent (e.g., medical or recreational marijuana, CBD) during the study period * Patients willing to take a second-generation antihistamine (loratadine) and an NSAID (aspirin). Patients already taking a daily antihistamine and/or NSAID can participate and will continue the class of drug already being taken * Ability to understand and the willingness to follow study procedures, including urine testing for THC. * Ability to understand and the willingness to sign a written informed consent document. Exclusion Criteria: * Contraindication to immunotherapy, aspirin, or loratadi…