Study to Evaluate Erlotinib With or Without SNDX-275 (Entinostat) in the Treatment of Patients With Advanced NSCLC

Inclusion Criteria

Cytologically or histologically confirmed NSCLC of stage IIIb or IV
Received at least 1 but no more than 2 prior chemotherapy or chemoradiotherapy regimens for advanced NSCLC (that did not include erlotinib and valproic acid) and progressed based on radiologic evidence
At least 1 measurable lesion by conventional or spiral computed tomography (CT) scan
Eastern Cooperative Oncology Group (ECOG) performance score of 0, 1, or 2 and life expectancy of at least 6 months
Paraffin-embedded tumor specimen available for correlative studies
Male or female over 18 years of age
Hemoglobin ≥ 9.0 g/dL; platelets ≥ 100 x 10^9/L; absolute neutrophil count (ANC) ≥ 1.5 x 10^9/L without the use of hematopoietic growth factors
Bilirubin and creatinine less than 2 times the upper limit of normal for the institution
Albumin ≥ 2.5 g/dL
Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) less than 3 times the upper limit of normal for the institution
Prothrombin time less than 1.5 times the upper limit of normal for the institution
Potassium, magnesium and phosphorus within the normal range for the institution (supplementation is permissible)
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
Patient or legally acceptable representative has granted written informed consent before any study-specific procedure (including special screening tests) are performed

Exclusion Criteria

Prior stem cell transplant
Clinical evidence of central nervous system (CNS) involvement
Prior treatment with an histone deacetylase (HDAC) inhibitor or an epidermal growth factor receptor (EGFR) inhibitor
Currently taking known inhibitors of CYPA4, including but not limited to atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, troleandomycin, ≥ 10 mg prednisone, and voriconazole
Currently taking medication(s) on the prohibited medication list
Prior exposure to SNDX-275
Systemic chemotherapy, radiotherapy, or treatment with an investigational agent without recovery to at least grade 1 or baseline before study drug administration
Daily treatment with ≥ 10 mg prednisone within 28 days before study drug administration
Local or whole brain palliative radiotherapy within 14 days before study drug administration
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, carcinoma in situ of the bladder, or papillary thyroid cancer
Inability to swallow oral medications or a gastrointestinal malabsorption condition
Acute infection requiring intravenous (IV) antibiotics, antivirals, or antifungals within 14 days before study drug administration
Known human immunodeficiency virus (HIV) infection, or active hepatitis B or C infection
Another serious or uncontrolled medical condition within 90 days before study drug administration such as acute myocardial infarction, angina, ventricular arrhythmias, hypertension, diabetes mellitus, or renal or hepatic insufficiency
Known hypersensitivity to benzamides
Women who are currently pregnant or breast-feeding
Patient currently is enrolled in (or completed within 28 days before study drug administration) another investigational drug study
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