Inclusion Criteria:

- Have a diagnosis of polycythemia vera (PV), essential thrombocythemia (ET), or
myelofibrosis (MF) as defined by the World Health Organization (WHO) diagnostic
criteria for myeloproliferative neoplasms (Swerdlow et al. 2008) and meet the
following additional subtype specific criteria:

- PV: have failed or is intolerant of standard therapies or refuses to take
standard medications

- ET: have failed or is intolerant of standard therapies or refuses to take
standard medications

- MF (participants with MF must meet at least 1 of the following): have
intermediate 1, intermediate 2, or high-risk MF according to the Dynamic
International Prognostic Scoring System (DIPPS Plus) for Primary Myelofibrosis
(Gangat et al. 2011); or have symptomatic MF with spleen greater than 10
centimeter (cm) below left costal margin; or have post-polycythemic MF; or have
post-ET MF

- All PV, ET, and MF participants must meet the following criteria:

o Have a quantifiable level of janus kinase 2 with a valine to phenylalanine
substitution at amino acid 617 (JAK2 V617F) mutation. This inclusion criterion will
not apply to the subset of participants in Cohorts 10 and 11 that must be negative
for the JAK2 V617F mutation

- Are ≥ 18 years of age

- Have given written informed consent prior to any study-specific procedures

- Have adequate organ function, including: Hepatic: Direct bilirubin ≤1.5 times upper
limits of normal (ULN), alanine transaminase (ALT), and aspartate transaminase (AST)
≤2.5 times ULN; Renal: Serum creatinine ≤1.5 times ULN; Bone Marrow Reserve: Absolute
neutrophil count (ANC) ≥1000/microliter (mcL), platelets ≥50,000/mcL for participants
with ET or PV and ≥25,000/mcL for participants with MF

- Have a performance status of 0, 1, or 2 on the Eastern Cooperative Oncology Group
(ECOG) scale

- Have discontinued all previous approved therapies for Myeloproliferative Neoplasms
(MPNs), including any chemotherapy, immunomodulating therapy (for example,
thalidomide, interferon-alpha), immunosuppressive therapy (for example,
corticosteroids >10 mg/day prednisone or equivalent), radiotherapy, and
erythropoietin, thrombopoietin, or granulocyte colony stimulating factor for at least
14 days and recovered from the acute effects of therapy. Hydroxyurea used to control
blood cell counts is permitted at study entry if the subject has been maintained on a
stable dose for at least 4 weeks. Low-dose acetylsalicylic acid (aspirin) is
permitted as well

- Are reliable and willing to make themselves available for the duration of the study
and are willing to follow study procedures

- Males and females with reproductive potential must agree to use medically approved
contraceptive precautions during the study and for 3 months following the last dose
of study drug

- Females with child-bearing potential must have had a negative urine pregnancy test ≤
7 days before the first dose of study drug and must also not be breastfeeding

- Are able to swallow capsules

- For participants who have undergone recent major surgery, at least 28 days must have
elapsed between surgery and study participation and the participant must have
achieved, in the opinion of the treating physician, at least a good recovery from the
surgical procedure

- Enrollment into Cohort 12 is limited to MF, PV, or ET participants, regardless of
mutational status, who, in addition to all other criteria, have demonstrated
intolerance to ruxolitinib, failure of primary response to ruxolitinib, or have
demonstrated disease progression while on ruxolitinib

Exclusion Criteria:

- Are currently enrolled in, or discontinued within the last 14 days from a clinical
trial involving an investigational product or non-approved use of a drug or device,
or concurrently enrolled in any other type of medical research judged not to be
scientifically or medically compatible with this study

- Have a corrected QT (QTc) interval >470 millisecond (msec) using Bazett's formula

- Have serious preexisting medical conditions that, in the opinion of the investigator
would preclude participation in the study (for example a gastrointestinal disorder
causing clinically significant symptoms such as nausea, vomiting, and diarrhea, or
malabsorption syndrome)

- Are currently being treated with agents that are metabolized by Cytochrome P450 3A4
enzyme (CYP3A4) with a narrow therapeutic margin (for example, alfentanil,
cyclosporine, diergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and
tacrolimus) or Cytochrome P450 2B6 enzyme (CYP2B6) (for example, cyclophosphamide,
ifosfamide, tamoxifen, efavirenz, propofol, methadone, and bupropion)

- Are currently being treated with warfarin or one of its derivatives which is known to
alter levels of protein C or protein S. An exception to this criterion will be
allowed for participants with a prior history of Budd-Chiari Syndrome who are being
treated with warfarin or one of its derivatives

- Have received a hematopoietic stem cell transplant

- Have a second primary malignancy that in the judgment of the Investigator and Sponsor
may affect the interpretation of results

- Have an active fungal, bacterial, and/or known viral infection including human
immunodeficiency virus (HIV) or viral (A, B, or C) hepatitis (screening is not
required)

- Have a history of congestive heart failure with New York Heart Association (NYHA)
Class >2 (NYHA Class 1 and 2 are eligible), unstable angina, recent myocardial
infarction (within 6 months prior to administration of study drug), or documented
history of ventricular arrhythmia