Inclusion Criteria

INCLUSION:

1. Cytologically or histologically confirmed NSCLC of stage IIIb (pleural effusion) or
IV

2. Disease is progressing (either no response to treatment or subsequent relapse after
an objective response) on erlotinib treatment, based on at least 2 scans (the last
being within 4 weeks of study enrollment and can serve as the baseline scan for the
patient's screening into the study )

3. Recovered from any toxicity associated with the most recent cancer treatment (no
greater than grade 1 toxicity on CTCAE scale or to prior baseline condition)

4. At least 1 measurable lesion ≥ 20mm by conventional CT scan or ≥ 10mm by spiral CT
scan

5. ECOG performance score of 0, 1, or 2 and life expectancy of at least 3 months

6. Paraffin-embedded tumor specimen available for correlative studies

7. Male or female over 18 years of age

8. Hemoglobin ≥ 9.0 g/dL; platelets ≥ 75 x 10⁹/L; ANC ≥ 1.0 x 10⁹/L without the use of
hematopoietic growth factors

9. Coagulation tests within the normal range

10. Bilirubin and creatinine less than 2 times the upper limit of normal for the
institution

11. AST and ALT less than 3 times the upper limit of normal for the institution

12. Potassium, magnesium and phosphorus within the normal range for the institution
(supplementation is permissible)

13. Willing to use accepted and effective methods of contraception during the study (both
men and women as appropriate) and for 3 months after the last dose of SNDX-275

14. Patient or legally acceptable representative has granted written informed consent
before any study-specific procedure (including special screening tests) is performed

EXCLUSION:

1. Prior stem cell transplant

2. Symptomatic CNS involvement

3. Prior treatment with an HDAC inhibitor

4. Concurrent anticancer therapy, with the exception of radiotherapy for a non-target
study lesion

5. Currently taking medication(s) on the prohibited medication list

6. Systemic chemotherapy or treatment with an investigational agent within 28 days
before enrollment

7. Current use of valproic acid

8. Untreated or unstable brain metastases, or taken steroids for this condition within 4
weeks of study drug administration

9. Currently active second malignancy, or any malignancy within the last 5 years other
than cured basal or squamous cell skin carcinoma, cervical carcinoma in situ, or
superficial bladder cancer

10. Inability to swallow oral medications or a gastrointestinal malabsorption condition

11. Uncontrolled infection requiring IV antibiotics, antivirals, or antifungals, known
HIV infection, or active hepatitis B or C infection

12. Abnormal cardiac function as defined as clinically significant findings on ECG
(multifocal PVCs, ST-T wave changes consistent with myocardial infarction or acute
ischemia, QTc greater than 500 milliseconds), tachycardia, or left ventricular
ejection fraction less than 40% on MUGA scan

13. Another serious or uncontrolled medical condition within 3 months of enrollment such
as hypertension, diabetes mellitus, or suppressed immune system

14. Known hypersensitivity to benzamides

15. Morbid obesity

16. Women who are currently pregnant or breast-feeding

17. Patient is currently enrolled in (or completed within 28 days) another
investigational drug study

18. Patient unavailable for on-study or follow-up assessments

19. Patient has any kind of medical, psychiatric, or behavioral disorder that places the
patient at increased risk for study participation or compromises the ability of the
patient to give written informed consent and/or to comply with study procedures and
requirements