Summary

This phase III trial studies how well combination chemotherapy, bevacizumab, and/or atezolizumab work in treating patients with deficient deoxyribonucleic acid (DNA) mismatch repair colorectal cancer that has spread from where it first started (primary site) to other places in the body (metastatic). Chemotherapy drugs, such as fluorouracil, oxaliplatin, and leucovorin calcium, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Bevacizumab may stop or slow colorectal cancer by blocking the growth of new blood vessels necessary for tumor growth. Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body’s immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving combination chemotherapy, bevacizumab, and atezolizumab may work better in treating patients with colorectal cancer.

Objectives

PRIMARY OBJECTIVE:
I. To determine the efficacy, based on progression-free survival (PFS), of fluorouracil, oxaliplatin, and leucovorin calcium (modified [m]FOLFOX6)/bevacizumab plus atezolizumab (combination) as compared to single agent atezolizumab.

SECONDARY OBJECTIVES:
I. To compare the overall survival.
II. To compare the objective response rates (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1.
III. To determine the safety profiles of single agent atezolizumab and the combination of mFOLFOX6/bevacizumab/atezolizumab in patients with mismatch-repair deficient (dMMR)/microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC).
IV. To determine the duration of response.
V. To determine the duration of stable disease.
VI. To determine the rate of progression-free survival (PFS) at 12 months.
VII. To evaluate the disease control rate (complete response [CR] + partial response [PR] + stable disease [SD]) at 12 months.

TRANSLATIONAL OBJECTIVE:
I. To bank tissue and blood samples for other future correlative studies from patients enrolled on the study.

OUTLINE: Patients are randomized to 1 of 3 arms.

ARM I: Patients receive bevacizumab intravenously (IV) over 30-90 minutes on day 1, oxaliplatin IV over 2 hours on day 1 of cycles 1-10, leucovorin calcium IV over 2 hours on day 1, and fluorouracil IV over 46-48 hours on days 1 and 2. Treatment with oxaliplatin repeats every 2 weeks for up to 10 cycles in the absence of disease progression or unacceptable toxicity. Treatment of bevacizumab, leucovorin calcium, and fluorouracil repeat every 2 weeks for up to 48 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo computed tomography (CT) with or without positron emission tomography (PET) or magnetic resonance imaging (MRI) throughout the trial. Patients may also undergo collection of optional blood samples throughout the trial. (CLOSED TO ACCRUAL)

ARM II: Patients receive atezolizumab IV over 30-60 minutes on day 1. Treatment repeats every 2 weeks for up to 48 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo CT with or without PET or MRI throughout the trial. Patients may also undergo collection of optional blood samples throughout the trial.

ARM III: Patients receive atezolizumab IV over 30-60 minutes on day 1. Treatment repeats every 2 weeks for up to 48 cycles in the absence of disease progression or unacceptable toxicity. Patients also receive bevacizumab IV over 30-90 minutes on day 1, oxaliplatin IV over 2 hours on day 1 cycles 1-10, leucovorin calcium IV over 2 hours on day 1, and fluorouracil IV over 46-48 hours on day 1. Treatment with oxaliplatin repeats every 2 weeks for up to 10 cycles in the absence of disease progression or unacceptable toxicity. Treatment of bevacizumab, leucovorin calcium, and fluorouracil repeat every 2 weeks for up to 48 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo CT with or without PET or MRI throughout the trial. Patients may also undergo collection of optional blood samples throughout the trial.

After completion of study treatment, patients are followed up every 8 weeks for 18 months, and then every 12 weeks for up to 5 years.

Eligibility

1. The patient must have signed and dated an Institutional Review Board (IRB)-approved consent form that conforms to federal and institutional guidelines
2. Age >= 18 years
3. Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2
4. Diagnosis of metastatic adenocarcinoma of colon or rectum without previous chemotherapy or any other systemic therapy for metastatic colorectal cancer except for one cycle of FOLFOX or capecitabine and oxaliplatin (CAPOX), either with or without bevacizumab prior to enrollment. Upon enrollment, the preceding single cycle of FOLFOX or FOLFOX + bevacizumab, if the patient received one, will not count towards patients’ assessments per protocol. Cycle 1 day 1 (C1D1) of atezolizumab or C1D1 of mFOLFOX6/bevacizumab + atezolizumab will correspond to the first day the patient received therapy on trial
5. Tumor determined to be mismatch-repair deficient (dMMR) by Clinical Laboratory Improvement Act (CLIA)-certified immunohistochemical (IHC) assay with a panel of all four IHC markers, including MLH1, MSH2, PMS2, and MSH6; alternatively, MSI-H diagnosed by polymerase chain reaction (PCR)-based assessment of microsatellite alterations (either Bethesda markers or Pentaplex panel) or by next-generation sequencing (NGS) are eligible
6. Documentation by PET/CT scan, CT scan, or MRI that the patient has measurable metastatic disease per RECIST 1.1
7. No immediate need for surgical intervention for the primary tumor or palliative diversion/bypass
8. Absolute neutrophil count (ANC) must be >= 1500/mm^3 (obtained within 28 days prior randomization)
9. Platelet count must be >= 100,000/mm^3 (obtained within 28 days prior randomization)
10. Hemoglobin must be >= 8 g/dL (obtained within 28 days prior randomization)
11. Total bilirubin must be =< 4 x ULN (upper limit of normal) (obtained within 28 days prior randomization); and
12. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) must be =< 3 x ULN for the lab with the following exception: for patients with documented liver metastases, AST and ALT must be =< 5 x ULN (obtained within 28 days prior randomization)
13. Calculated creatinine clearance >= 30 mL/min (obtained within 28 days prior randomization)
14. A urine sample tested for proteinuria by either the dipstick method, urinalysis (UA), or a urine protein creatinine (UPC) ratio: * The dipstick method must indicate 0-1+ protein; if dipstick reading is >= 2+, a 24-hour urine must be done and it must demonstrate < 1.0 g of protein per 24 hours or a UPC ratio < 1.0 * A urine protein creatinine (UPC) ratio must be < 1.0; if the UPC ratio is >= 1.0 a 24-hour urine must be done and it must demonstrate < 1.0 g of protein per 24 hours * Urinalysis must indicate < 30 mg/dl. If urinalysis >= 30 mg/dl, a 24-hour urine must be done and it must demonstrate < 1.0 g of protein per 24 hours or a UPC ratio < 1.0
15. International normalized ratio of prothrombin time (INR) and prothrombin time (PT) must be =< 1.5 x ULN for the lab within 28 days before randomization; patients who are therapeutically treated with an agent such as warfarin may participate if they are on a stable dose and no underlying abnormality in coagulation parameters exists per medical history, regardless of PT/INR results
16. Pregnancy test done within 28 days prior randomization must be negative (for women of childbearing potential only); pregnancy testing should be performed according to institutional standards; administration of atezolizumab or mFOLFOX6/bevacizumab/atezolizumab may have an adverse effect on pregnancy and poses a risk to the human fetus, including embryo-lethality; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately
17. Women of child-bearing potential and men must agree to use adequate contraception methods that result in a failure rate of < 1% per year during the treatment period (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for 5 months (150 days) after the last dose of atezolizumab, 6 months after the last dose of bevacizumab, and 6 months after the last dose of mFOLFOX6; a woman is considered to be of childbearing potential if she is not postmenopausal, has not reached a postmenopausal state (>= 12 continuous months of amenorrhea with no identified cause other than menopause), and has not undergone surgical sterilization (removal of ovaries and/or uterus); examples of contraceptive methods with a failure rate of < 1% per year include: bilateral tubal ligation; male partner sterilization; intrauterine devices; the reliability of sexual abstinence should be evaluated in relation to the duration of the clinical study and the preferred and usual lifestyle of the patient; periodic abstinence (e.g., calendar, ovulation, symptothermal, or postovulation methods) and withdrawal are not acceptable methods of contraception; men must refrain from donating sperm during this same period

Treatment Sites in Georgia