A Phase 2 Multi-Center Study of Entinostat (SNDX-275) in Patients With Relapsed or Refractory Hodgkin's Lymphoma

Inclusion Criteria:

1. Pathologic confirmation of relapsed or refractory classical Hodgkin's lymphoma from
the last biopsy available. Relapsed disease is defined as progressive disease
following systematic therapy(ies) with curative intent. Refractory disease is defined
as disease not responding to or having progressed within 3 months of the last dose of
most recent systemic therapy

2. Must have progressed after, or been ineligible for, stem cell transplantation

3. Documented disease that is radiographically measurable (≥ 1.5 cm in the largest
transverse dimension). If only 1 site of radiographically measurable lesion with the
longest diameter < 2.5 cm, lesion must be positive by FDG-PET or biopsy.

4. Last dose of cytotoxic chemotherapy must be > 21 days before the first dose of study
drug.

5. ECOG performance status of 0 or 1

6. Age 18 years or older

7. Total Bilirubin ≤ 1.5 x ULN and AST and ALT ≤ 2.5 x ULN, possible exceptions if
documented HL liver involvement.

8. Serum Creatinine ≤ 1.5 x ULN

9. Absolute neutrophil counts of ≥ 1,000/µL, and platelet counts ≥ 50,000/µL

10. Patients or their legal representative must be able to read, understand, and sign a
written informed consent

Exclusion Criteria:

1. Patients with another active cancer (excluding basal cell carcinoma or CIN/cervical
carcinoma in situ or melanoma in situ). Prior history of other cancer is allowed,
excluding active disease within the prior 5 years.

2. Prior allogeneic stem cell transplantation requiring active immunosuppressive therapy
within 3 months of registration or with evidence of active GVHD.

3. Pregnant or lactating women. Women of child-bearing potential (WOCBP) must have a
negative serum pregnancy test prior to start of study drug.

4. WOCBP and men whose partners are WOCBP must use an acceptable method of contraception
while enrolled on this study, and for a period of 3 months following the last dose of
study drug.

5. Patients with uncontrolled intercurrent illness, active or uncontrolled infections,
or a fever > 38.5⁰C that has not been evaluated for infection on the day of scheduled
dosing.

6. Patients who have been treated with any investigational drug within 28 days prior to
the first dose of study medication, or who are receiving concurrent treatment with
other experimental drugs or anti-cancer therapy.

7. Prior treatment with HDAC inhibitors (e.g. valproic acid, Zolinza (SAHA), romidepsin
(Istodax),and experimental compounds such as MethylGene's MCGD0103 and Novartis'
LBH589)

8. History of pericarditis or pericardial effusion that had required medical or surgical
intervention in the last 6 months, or myocardial infarction or arterial
thromboembolic events within 6 months, or experiencing severe or unstable angina, or
New York Heart Association (NYHA) Class III or IV disease or a QTc interval >0.47
seconds

9. Known HIV or a history of active Hepatitis B or C as evidenced by laboratory
abnormalities in addition to positive serology.

10. Active central nervous system lymphoma and lymphoma with leptomeningeal involvement

11. Any condition (e.g., known or suspected poor compliance, psychological instability,
geographical location, etc) that, in the judgment of the investigator, may affect the
patient's ability to sign the informed consent and comply with study procedures

12. Any condition that will put the patient at undue risk or discomfort as a result of
adherence to study procedures

13. History of gastrointestinal disorders (medical disorder or extensive surgery) that
could interfere with absorption of study drug.