This study will evaluate the safety, tolerability, pharmacokinetic profile and treatment effect of a new drug known as BGB-283 in patients with solid tumours.

Inclusion Criteria:

1. Provided written informed consent prior to enrollment.

2. Male or female and at least 18 years of age.

3. A life expectancy of at least 12 weeks.

4. Histologically or cytologically confirmed advanced or metastatic solid tumor for which no effective standard therapy is available.

5. One of B-RAF, N-RAS, or K-RAS mutation positive solid tumor.

6. Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 1.

7. Able to swallow and retain oral medication.

8. Adequate bone marrow, liver, and renal function:

   • Hemoglobin > 9 g/dL
   • Absolute neutrophil count ≥ 1000/mm^3
   • Platelets ≥ 100,000/mm^3
   • Total bilirubin ≤1.5 times the upper limit of normal (ULN)
   • Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 x ULN (≤ 5 x ULN for subjects with known liver metastasis)
   • Creatinine clearance ≥ 45 mL/min (calculated by the Cockcroft Gault formula).

9. Female subjects are eligible to enter and participate in the study if they are of:

   a) Non childbearing potential (i.e., physiologically incapable of becoming pregnant), including any female who

   i) Has had a hysterectomy,

   ii) Has had a bilateral oophorectomy (ovariectomy),

   iii) Has had a bilateral tubal ligation, or

   iv) Is post menopausal (total cessation of menses for ≥ 1 year).

   b) Childbearing potential, has a negative serum pregnancy test at screening (within 7 days of the first investigational product administration), and uses adequate contraception before study entry and throughout the study until 28 days after the last investigational product administration. Adequate contraception, when used consistently and in accordance with both the product label and the instructions of the physician, are defined as follows:

   i) Vasectomized partner who is sterile prior to the female subject's entry and is the sole sexual partner for that female.

   ii) Any intrauterine device with a documented failure rate of less than 1% per year.

   iii) Double barrier contraception defined as condom with spermicidal jelly, foam, suppository, or film; OR diaphragm with spermicide; OR male condom and diaphragm.

10. Subjects with treated brain metastasis are eligible to enter and participate in the study if they are neurologically stable.

Exclusion Criteria:

1. Female subjects who are pregnant or lactating.
2. Subjects receiving cancer therapy (chemotherapy or other systemic anti cancer therapies, immunotherapy, radiation therapy, or surgery) at the time of enrollment.
3. Any major surgery within 28 days prior to enrollment.
4. Any radiotherapy within 14 days prior to enrollment, providing the subject has recovered from all toxicities to NCI-CTCAE ≤ Grade 1.
5. Use of any investigational anti cancer drug within 28 days before the first investigational product administration.
6. Unresolved toxicity > Grade 1 (according to NCI-CTCAE, Version 4.03) from previous anti cancer therapy, unless agreed by the sponsor.
7. History or presence of gastrointestinal disease or other condition known to interfere with the absorption, distribution, metabolism, or excretion of drugs.
8. Known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs chemically related to the study drug or to any component of BGB-283. (To date there are no known Food and Drug Administration [FDA] approved drugs chemically related to BGB-283).
9. Untreated leptomeningeal or brain metastasis. Subjects with previously treated brain metastasis that are asymptomatic, off steroids for longer than 28 days are permitted.
10. Any unstable, pre-existing major medical condition that in the opinion of the Investigator contra indicates the use of an investigational product, including active infection, known human immunodeficiency virus (HIV) positive subjects, or known Hepatitis B or C.
11. Psychological, familial, sociological, or geographical conditions that do not permit compliance with the protocol.
12. As a result of the medical interview, physical examination or screening investigations, the investigator considers the subject unfit for study.
13. Is on medication listed in the protocol or requires any of these medications during treatment with BGB-283.
14. Candidates for curative therapy.
15. Unable or unwilling to comply with the required treatment.

Upon request, and subject to certain criteria, conditions, and exceptions, BeiGene will provide access to individual de-identified participant data from BeiGene-sponsored global interventional clinical studies conducted for medicines for indications that have been approved or in programmes that have been terminated. BeiGene will also consider requests for the protocol, data dictionary, and statistical analysis plan. Data requests can be submitted to medicalinformation@beigene.com.