Dabrafenib + Trametinib + PDR001 In Colorectal Cancer

- This research study is a Phase II clinical trial. Phase II clinical trials test the
safety and effectiveness of an investigational drug combination to learn whether the
drug combination works in treating a specific disease. "Investigational" means that the
drug combination is being studied.

- The FDA (the U.S. Food and Drug Administration) has not approved PDR001 as a
treatment for any disease.

- The FDA has not approved dabrafenib and trametinib for your specific disease but it
has been approved for other uses, whether alone as single agents, or given together
as in this study.

- This research study is studying a combination of drugs as a possible treatment for
metastatic colorectal cancer characterized by BRAF V600E mutation.

- All humans have a gene called BRAF which is responsible for sending signals to
proteins called B-Raf inside of cells that help them grow. In some metastatic
colorectal patients, this gene mutates and causes cancer cells to grow in
uncontrolled ways.

--- Dabrafenib is a drug that is thought to inhibit the mutant BRAF activity, which
may serve to slow or stop cell growth of metastatic colon cancer.

- Mitogen-activated protein kinase (MAPK) is a pathway that helps to activate the
BRAF mutated genes. The MAPK pathway is commonly found to be overactivated in BRAF
mutated tumor cells. MEK (which refers to MAPK/ERK Kinase) enzymes are essential to
the activity of the MAPK pathway.

- Trametinib inhibits the MEK enzymes in order to shut down the MAPK pathway,
thus blocking the pathway that helps the cancer cells grow uncontrollably.

- PDR001 is a drug which binds to PD1 on immune cells and is believed to block
binding of PD-L1 and PD-L2. PD-L1/PDL1 and PD-L2/PDL2 are often used by cancer
cells and to escape the power of the body's immune system so that they cannot
be fought. By blocking that binding of the molecules, the body's immune system
may reach and fight the cancer cells. Researchers are hoping that
administration of all three of these drugs may help anti-cancer activities
work together to slow or stop the cancer growth and may help your own immune
system damage or destroy the existing cancer cells.

Inclusion Criteria:

- Participants must have histologically or cytologically confirmed metastatic colorectal
cancer and a documented BRAF V600E mutation by a CLIA-certified laboratory test and
must be wild-type for KRAS and NRAS.

- Participants must have measurable disease, defined as at least one lesion that can be
accurately measured in at least one dimension (longest diameter to be recorded for
non-nodal lesions and short axis for nodal lesions) as ≥20 mm with conventional
techniques or as ≥10 mm with spiral CT scan, MRI, or calipers by clinical exam. See
Section 11 for the evaluation of measurable disease.

- Patients may have received prior chemotherapy, prior anti-EGFR therapy, prior BRAF or
MEK inhibitor, or prior immunotherapy (e.g. anti-PD1/PD-L1). Patients will also be
allowed without prior treatments. If patient has been treated in the past, they must
be at least 4 weeks since prior chemotherapy or radiation therapy.

- Age ≥ 18 years

- ECOG performance status ≤2 (Karnofsky ≥60%, see Appendix A)

- Life expectancy of greater than 3 months

- Participants must have normal organ and marrow function as defined below:

- leukocytes ≥3,000/mcL

- absolute neutrophil count ≥1,500/mcL

- platelets ≥100,000/mcL

- total bilirubin within normal institutional limits

- AST(SGOT)/ALT(SGPT) ≤2.5 × institutional upper limit of normal

- creatinine within normal institutional limits --- OR

- creatinine clearance ≥ 60 mL/min/1.73 m2 for participants with creatinine levels above
institutional normal.

- PT/INR <1.5 x ULN and PTT <1.5 ULN

- Albumin > 2.5 g/dl

- Patients must meet eligibility criteria on C1D1.

- LVEF > LLN by ECHO or MUGA

- The effects of trametinib, dabrafenib and PDR001 on the developing human fetus are
unknown. For this reason and because these agents may be teratogenic, women of
child-bearing potential and men must agree to use adequate contraception (hormonal or
barrier method of birth control; abstinence) prior to study entry and for the duration
of study participation. 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. Men treated or enrolled on this protocol must also
agree to use adequate contraception prior to the study, for the duration of study
participation, and 4 months after completion of treatment.

- Ability to understand and the willingness to sign a written informed consent document.

- Subjects must avoid consumption of grapefruit, Seville oranges or products containing
the juice of each during the entire study and preferably 7 days before the first dose
of study medications, due to potential CYP3A4 interaction with the study medications.
Orange juice is allowed.

- Exclusion Criteria

- Participants who have had chemotherapy or radiotherapy within 4 weeks prior to
entering the study or those who have not recovered from adverse events due to agents
administered more than 4 weeks earlier.

- Participants who are receiving any other investigational agents.

- Participants with known brain metastases should be excluded from this clinical trial
because of their poor prognosis and because they often develop progressive neurologic
dysfunction that would confound the evaluation of neurologic and other adverse events.

- History of allergic reactions attributed to compounds of similar chemical or biologic
composition to of trametinib, dabrafenib or PDR001.

- Participants receiving any medications or substances that are strong inhibitors or
inducers of CYP3A4 are ineligible but once on treatment must be used with caution.
Because the lists of these agents are constantly changing, it is important to
regularly consult a frequently-updated list such as
http://medicine.iupui.edu/clinpharm/ddis/table.aspx; medical reference texts such as
the Physicians' Desk Reference may also provide this information. As part of the
enrollment/informed consent procedures, the patient will be counseled on the risk of
interactions with other agents, and what to do if new medications need to be
prescribed or if the patient is considering a new over-the-counter medicine or herbal
product.

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situations that would limit compliance with
study requirements.

- Pregnant women are excluded from this study because trametinib, dabrafenib or PDR001
have the potential for teratogenic or abortifacient effects. Because there is an
unknown but potential risk for adverse events in nursing infants secondary to
treatment of the mother with trametinib, dabrafenib or PDR001 breastfeeding should be
discontinued if the mother is treated with trametinib, dabrafenib or PDR001.

- HIV-positive participants on combination antiretroviral therapy are ineligible because
of the potential for pharmacokinetic interactions with trametinib, dabrafenib or
PDR001. In addition, these participants are at increased risk of lethal infections
when treated with marrow-suppressive therapy. Appropriate studies will be undertaken
in participants receiving combination antiretroviral therapy when indicated.

- Active known or suspected autoimmune disease or a documented history of autoimmune
disease, including ulcerative colitis and Crohn's disease (Subjects with vitiligo,
type I diabetes mellitus, residual hypothyroidism due to autoimmune condition only
requiring hormone replacement, psoriasis not requiring systemic treatment, or
conditions not expected to recur in the absence of an external trigger are permitted
to enroll).

- Systemic chronic steroid therapy (≥ 10mg/day prednisone or equivalent) or any
immunosuppressive therapy 7 days prior to planned date for first dose of study
treatment. Topical, inhaled, nasal and ophthalmic steroids are allowed.

- Current pneumonitis or interstitial lung disease.

- History of organ transplant requiring use of immunosuppressive medication.

- Taken an investigational drug ≤ 28 days or ≤ 5 half-lives (minimum 14 days) prior to
start of study treatment, whichever is shorter.

- Current use of a prohibited medication.

- Malignant disease, other than that being treated in this study. Exceptions to this
exclusion include the following: malignancies that were treated curatively and have
not recurred within 2 years prior to study treatment; completely resected basal cell
and squamous cell skin cancers and any completely resected carcinoma in situ.

- Active infection requiring systemic antibiotic therapy within 2 weeks prior to start
of study treatment.

- Subjects with active Hepatitis B infection (HbsAg positive) will be excluded. Note:
Subjects with antecedent of Hepatitis B (anti-HBc positive, HbsAg and HBV-DNA
negative) are eligible.

- Subjects with positive test for hepatitis C ribonucleic acid (HCV RNA) Note: Subjects
in whom HCV infection resolved spontaneously (positive HCV antibodies without
detectable HCV-RNA) or those that achieved a sustained virological response after
antiviral treatment and show absence of detectable HCV RNA ≥ 6 months (with the use of
IFN-free regimes) or ≥ 12 months (with the use of IFN-based regimes) after cessation
of antiviral treatment are eligible.

- Any medical condition that would, in the investigator's judgment, prevent the
subject's participation in the clinical study due to safety concerns, compliance with
clinical study procedures or interpretation of study results.

- Use of any live vaccines against infectious diseases within 4 weeks of initiation of
study treatment

- Uncorrectable electrolyte abnormalities (e.g., hypokalemia, hypomagnesemia,
hypocalcemia), long QT syndrome or taking medicinal products known to prolong the QT
interval

- Known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs
chemically related to the study treatments, their excipients, and/or dimethyl
sulfoxide (DMSO).

- A history or current evidence/risk of retinal vein occlusion (RVO) or central serous
retinopathy including:

- Presence of predisposing factors to RVO or central serous retinopathy (e.g.,
uncontrolled glaucoma or ocular hypertension, uncontrolled hypertension,
uncontrolled diabetes mellitus, or a history of hyperviscosity or
hypercoagulability syndromes); or

- Visible retinal pathology as assessed by ophthalmic examination that is
considered a risk factor for RVO or central serous retinopathy such as:

- Evidence of new optic disc cupping;

- Evidence of new visual field defects on automated perimetry;

- Intraocular pressure >21 mmHg as measured by tonometry.

- Cardiac or cardiac repolarization abnormality, including any of the following:

- History or current diagnosis of cardiac disease indicating significant risk of
safety for subjects participating in the study such as uncontrolled or
significant cardiac disease, including any of the following:

- Recent (within last 6 months) myocardial infarction (MI)

- Unstable angina (within last 6 months),

- Uncontrolled congestive heart failure (CHF)

- Clinically significant (symptomatic) cardiac arrhythmias (e.g., sustained
ventricular tachycardia, and clinically significant second or third degree
atrioventricular [AV] block without a pacemaker).