Key Exclusion Criteria:

1) The patient has a history of, or a concurrent, clinically significant illness, medical condition or laboratory abnormality that, in the investigator?s opinion, could affect the conduct of the study.

2) Has a B-cell lymphoma, primary CNS lymphoma, or known lymphomatous involvement of the CNS, or any other NK/T-cell leukemias/lymphomas such as:
- Precursor T-lymphoblastic lymphoma/leukemia
- T-cell prolymphocytic leukemia
- T-cell granular lymphocytic leukemia
- NK-cell leukemia
- Anaplastic large cell lymphoma, T/null-cell, primary cutaneous type
- Non-transformed mycosis fungoides
- Sezary syndrome

3) Has uncontrolled or poorly controlled hypertension
(> 160/110 mmHg).

4) Has had recent (within 1 month prior to Day 1) serious surgery or infectious disease.

5) Has a recent history (within 2 years prior to Day 1) of, or treatment for, a malignancy other than nonmelanomatous skin cancer or carcinoma in situ of the cervix.

6) Has a known positive test for Hepatitis B surface Ag, Hepatitis C, or HIV.

7) Has any of the following laboratory abnormalities:
- Bone marrow impairment: ANC < 1,000/&#541;L (1 x 109/L); platelets < 50,000/&#541;L (50 x 109/L)
- Impairment of renal function: creatinine > 1.5 mg/dL (114.4 &#956;mol/L) or calculated CrCl < 60 mL/minute (1.002 mL/s)
- Abnormal liver function: AST/ALT > 3x ULN (up to 5x ULN with liver involvement); bilirubin > 1.5 mg/dL (25.7 &#956;mol/L)

8) Has significant gastrointestinal disease (Crohn?s or ulcerative colitis) not related to the underlying lymphoma.

9) Has difficulty swallowing or malabsorption.

10) Has an ECOG performance status > 2 (Protocol Appendix II).

11) Has received chemotherapy within 4 weeks of Day 1 of treatment (6 weeks for mitomycin C and nitrosoureas).

12) Has received antibody therapy or lymphoma vaccine therapy within 6 weeks of Day 1 of treatment.

13) Has received radiotherapy within 2 weeks of Day 1 of treatment, 4 weeks if to marrow-bearing sites (sternum, pelvis).

14) Has had an auto- or allotransplantation within 90 days prior to Day 1 of treatment.

15) Has been treated with a CYP3A4 inducer/inhibitor within 3 days prior to Day 1 of treatment or is expected to require treatment with CYP3A4 inducer/inhibitor during the course of the study. Refer to Protocol Appendix III (the active metabolite of R788 is metabolized by CYP3A4, and ketoconazole increases the AUC of a dose of R788 by approximately 2-fold).

16) Has received systemic steroids at a dose greater than the equivalent of 10 mg/day of prednisone within 4 weeks prior to Day 1 of treatment. Systemic steroids at a dose less than the equivalent of 10 mg/day of prednisone and inhaled, nasal, and topical steroids are permitted. Intermittent dexamethasone for the treatment of nausea/emesis is also permitted.

17) Has received any other investigational therapy within 4 weeks of Day 1 of treatment.

18) Is a female of childbearing potential unless menopausal, surgically sterile, or willing to use a well established method of birth control, (oral contraceptive, mechanical barrier, long-acting hormonal agent), during the study and for 30 days thereafter.

19) Is pregnant or lactating: all females of childbearing potential must have a negative urine pregnancy test within 7 days of Day 1 of study drug administration