Capecitabine and Bevacizumab With or Without Atezolizumab in Treating Patients With Refractory Metastatic Colorectal Cancer

Inclusion Criteria

• Histologically confirmed colorectal cancer that is either clinically or histologically proven to be metastatic and has progressed on regimens containing a fluoropyrimidine (e.g., 5-fluorouracil or capecitabine), oxaliplatin, irinotecan, bevacizumab and an anti-EGFR antibody (if tumor is RAS wild-type), or where the treatment was not tolerated or contraindicated
• Measurable disease; Note: previously irradiated sites can be included if there is documented disease progression in that site
• Capecitabine and bevacizumab considered appropriate treatment for the patient
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1
• Absolute neutrophil count >= 1, 500/uL (obtained = = 100,000/uL (obtained = = 9 g/dL continuation of erythropoietin products is permitted (obtained = = 9 g/dL >= 14 days without blood transfusion to maintain hemoglobin level
• Calculated creatinine clearance must be >= 50 ml/min using the Cockcroft-Gault formula or a 24 hour urine (obtained = = 3 months

Exclusion Criteria

• Any of the following:
• Pregnant women
• Nursing women
• Women of child-bearing potential must agree to use two forms of adequate contraception from time of initial consent, for the duration of study participation, and for >= 6 months after the last dose of study drug; medically acceptable contraceptives include: (1) surgical sterilization (such as a tubal ligation or hysterectomy), (2) approved hormonal contraceptives (such as birth control pills, patches, implants or injections), (3) barrier methods (such as a condom or diaphragm) used with a spermicide, or (4) an intrauterine device (IUD); contraceptive measures such as Plan B, sold for emergency use after unprotected sex, are not acceptable methods for routine use; postmenopausal woman must have been amenorrheic for at least 2 years to be considered of non-childbearing potential; sexually active men must use at least one form of adequate contraception from time of initial consent, for the duration of study participation, and for >= 6 months after the last dose of study drug
• Chemotherapy, biologic anti-cancer therapy, or central field radiation therapy = 150 mmHg and/or diastolic blood pressure > 100 mmHg)
• History of hypertensive crisis or hypertensive encephalopathy
• New York Heart Association (NYHA) grade II or greater congestive heart failure
• History of myocardial infarction, unstable angina, cardiac or other vascular stenting, angioplasty, or surgery = = 2+ protein by urinalysis (UA) or >= 1 gram protein by 24 hour urine collection; Note: Subjects that are >= 2+ or greater on dipstick but 325 mg/day), or clopidogrel (> 75 mg/day)
• Current or recent (= = 14 days at the time of randomization; prophylactic use of anticoagulants is allowed
• History or recent diagnosis of demyelinating disease
• History of other carcinoma =< 3 years; exception: if risk of recurrence is known to be under 5% at time of randomization
• Current or recent (=< 90 days prior to randomization) endoluminal stent in the stomach, bowel, colon or rectum
• Colonoscopy, sigmoidoscopy, or proctoscopy =< 7 days prior to randomization
• Current or recent (=< 28 days prior to randomization) use of sorivudine, brivudine, and St. John?s wort
• Primary or secondary immunodeficiency (history of or currently active) unless related to primary disease under investigation
• Prior allogeneic bone marrow transplantation or prior solid organ transplantation
• Treatment with systemic immunosuppressive medications (including but not limited to prednisone, cyclophosphamide, azathioprine, methotrexate, thalidomide, and anti-tumor necrosis factor [anti-TNF] agents) =< 14 days prior to randomization; exception: patients who have received acute, low-dose, systemic immunosuppressant medications (e.g. a one-time dose of dexamethasone for nausea) are eligible; the use of inhaled corticosteroids and mineral-corticoids (e.g. fludrocortisone) for patients with orthostatic hypotension or adrenoco