This Study is Comparing Morning vs Random Scheduling of Standard of Care Pembrolizumab Checkpoint Inhibitor Immunotherapy Infusions in Patients With Metastatic Non-small Cell Lung Cancer

Inclusion Criteria: 1. Patients with histologic diagnosis mNSCLC with PDL1 staining ≥ 50% on standard of care IHC testing 2. Patients must be eligible for treatment with standard-of-care pembrolizumab 3. Patients must be 18 years of age or older. 4. Patients must be capable of providing consent to enrolment and willing to comply with study, treatment and follow-up. 5. Patients with a performance status of Eastern Cooperative Oncology Group (ECOG) performance status 0-2 (Oken et al., 1982) will be eligible for enrolment 6. Women of childbearing potential (WOCBP) must have a negative serum (or urine) pregnancy test within 7 days prior to the first dose of pembrolizumab. WOCBP is defined as any female who has experienced menarche and who has not undergone surgical sterilization (hysterectomy or bilateral oophorectomy or bilateral salpingectomy) and is not postmenopausal. Menopause is defined as 12 months of amenorrhea in a woman over age 45 years in the absence of other biological or physiological causes. 7. Patients of childbearing / reproductive potential should use adequate birth control methods, as defined by the investigator, during the study treatment period. A highly effective method of birth control is defined as those that result in low failure rate (i.e. less than 1% per year) when used consistently and correctly. Note: abstinence is acceptable if this is established and preferred contraception for the patient and is accepted as a local standard. 8. Absence of any condition hampering compliance with the study protocol and follow- up schedule; those conditions should be discussed with the patient before registration in the trial. 9. The following adequate organ function laboratory values must be met: Hematological: * Absolute neutrophil count (ANC) \>1.0 * Platelet count \>100 * Hemoglobin \>90 mg/dL Renal: o Serum creatinine \<3x upper limited of normal (ULN) Hepatic: * Total serum bilirubin \<2x ULN * AST and ALT \<3x ULN Coagulation: o International Normalized Ratio (INR) \<1.5x ULN (unless patient is receiving anticoagulant therapy and if PT or PTT is within therapeutic range of intended use of anticoagulants) Exclusion Criteria: 1. Concurrent therapy with systemic therapy other than pembrolizumab (such as chemotherapy, targeted therapy, other checkpoint inhibitors, or hormonal therapy). 2. Treatment plan includes local therapy such as radiation or surgery. 3. Untreated symptomatic brain metastases, or previously treated brain metastases requiring corticosteroids for symptom control. Patients with untreated asymptomatic brain metastases, where all lesions are \< 2cm in size with no vasogenic edema, are eligible. 4. Presence of leptomeningeal disease. 5. Known history of human immunodeficiency virus (HIV), active Hepatitis B or Hepatitis C. Testing for HIV, HBV or HCV is not mandatory for enrolment to study but may occur at the discretion of the investigator. 6. Active autoimmune disease that has required systemic treatment in past 12 months (i.e. with use of disease modifying agents, requiring \>10mg prednisone or equivalent or other immunosuppressive drugs). Replacement therapy (e.g. thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment. 7. Participant unwilling to agree to their treatment times being scheduled as per study protocol during the study treatment period (Cycles 1-6).