Immune Checkpoint Inhibitor (ICI)-Drug-Drug Interaction (DDI) Study

Inclusion Criteria: * ≥ 18 years old at the time of informed consent * Diagnosed with cancer AND initiating therapy with single agent or combination therapy that includes an immune checkpoint inhibitor (e.g., atezolizumab, cemiplimab, durvalumab, ipilimumab, nivolumab, pembrolizumab, relatlimab, tremelimumab) * Ability to provide written informed consent and HIPAA authorization Exclusion Criteria: * Actively pregnant or breastfeeding * Body weight less than 50 kg or a BMI \>35 * Low baseline hemoglobin, defined as \<10 g/dL * Note: if a prospective patient's hemoglobin returns to the normal range, they can be re-screened for trial inclusion) * Past medical history of chronic liver disease, signs and symptom of liver disease (e.g., jaundice, ascites), or aspartate aminotransferase \>96 U/L, alanine aminotransferase \> 80 IU/L, alkaline phosphatase \>260 U/L, or total bilirubin \> 2.6 mg/dL * Note: if a prospective patient's liver function tests return to the normal ranges, they can be re-screened for trial inclusion) * Past medical history of chronic kidney disease, signs and symptom of kidney disease (e.g., decreased urine output, swelling in feet and ankles), or estimated glomerular filtration rate \<45 mL/minute/1.73 m2 BSA * Note: if a prospective patient's kidney function returns to the normal range, they can be re-screened for trial inclusion) * Poor performance status that makes it unlikely the patient will complete 3 cycles of immune checkpoint inhibitor (a…