Study of Binimetinib + Nivolumab Plus or Minus Ipilimumab in Patients With Previously Treated Microsatellite-stable (MSS) Metastatic Colorectal Cancer With RAS Mutation

Key Inclusion Criteria

* Measurable, histologically/cytologically confirmed metastatic colorectal cancer (mCRC).
* Able to provide a sufficient amount of representative tumor specimen for central laboratory testing of RAS mutation status and microsatellite stable (MSS).

  * If a fresh tissue sample is provided, a blood sample is required.
* Metastatic colorectal cancer (mCRC) categorized as microsatellite stable (MSS) by polymerase chain reaction (PCR) per local assay at any time prior to Screening or by the central laboratory.
* RAS mutation per local assay at any time prior to Screening or by the central laboratory.
* Have received at least 1 prior line of therapy and meets at least one of the following criteria:

  * were unable to tolerate the prior first-line regimen
  * experienced disease progression during or after prior first-line regimen for metastatic disease
  * progressed during or within 3 months of completing adjuvant chemotherapy. Note: Generally, treatments that are separated by an event of progression are considered different regimens.
* Have received no more than 2 prior lines of therapy (maintenance therapy given in the metastatic setting will not be considered a separate regimen). Generally, treatments that are separated by an event of progression are considered different regimens.
* Adequate bone marrow, cardiac, kidney and liver function
* Able to take oral medications
* Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1.
* Female patients are either postmenopausal for at least 1 year, are surgically sterile for at least 6 weeks, or must agree to take appropriate precautions to avoid pregnancy from screening through follow-up if of child-bearing potential
* Non-sterile male patients who are sexually active with female partners of childbearing potential must agree to follow instructions for acceptable or highly effective method(s) of contraception for the duration of study treatment and for 7 months after the last dose of study treatment with nivolumab

Key Exclusion Criteria

* Prior treatment with any MEK inhibitor, an anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CD137, or anti-CTLA-4 antibody, or any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint pathways.
* Any untreated central nervous system (CNS) lesion.
* Patients with an active, known or suspected autoimmune disease. Patients with type I diabetes mellitus, hypothyroidism only requiring hormone replacement, skin disorders (such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment, or conditions not expected to recur in the absence of an external trigger are permitted to enroll.
* Known history of retinal vein occlusion (RVO).
* Known history of Gilbert's syndrome.
* Pregnant or breastfeeding females.
* Treatment with systemic immunosuppressive medications (including but not limited to prednisone, cyclophosphamide, azathioprine, methotrexate, thalidomide, and anti-tumor necrosis factor \[anti-TNF\] agents) within 2 weeks prior to first day of study treatment:
* History of thromboembolic or cerebrovascular events ≤ 6 months prior to starting study treatment, including transient ischemic attacks, cerebrovascular accidents, deep vein thrombosis or pulmonary emboli.
* Uncontrolled hypertension defined as persistent systolic blood pressure ≥ 150 mmHg or diastolic blood pressure ≥ 100 mmHg despite current therapy.
* Concurrent neuromuscular disorder that is associated with the potential of elevated creatine kinase (CK) (e.g., inflammatory myopathies, muscular dystrophy, amyotrophic lateral sclerosis, spinal muscular atrophy).
* History or current evidence of retinal vein occlusion (RVO) or current risk factors for RVO (e.g., uncontrolled glaucoma or ocular hypertension, history of hyperviscosity or hypercoagulability syndromes).
* Known history of positive test for human immunodeficiency virus (HIV) or known acquired immunodeficiency syndrome (AIDS). NOTE: Testing for HIV must be performed at sites where mandated locally.
* Any positive test for hepatitis B virus or hepatitis C virus indicating acute or chronic infection, and/or detectable virus.