A Double-blind Study Evaluating IPI-504 and Docetaxel in Patients With Non-Small Cell Lung Cancer

Inclusion Criteria: * Patients must be ≥18 years of age * Voluntarily signed an informed consent * Confirmed NSCLC and Stage IIIB or IV disease. * At least a ≥15 pack year smoking history and must have been an active smoker within 20 years of diagnosis. * Must have archival NSCLC tissue available to provide for analysis or have a lesion that is accessible for biopsy * Must have experienced disease progression during or after receiving at least 1 prior platinum-containing chemotherapy regimen. * Must have received no more than 2 prior chemotherapy regimens * Measurable disease by RECIST 1.1 criteria. * ECOG performance status of 0 or 1 (Refer to scale in Appendix 1). * Women of child-bearing potential (WCBP), all sexually active male patients, and partners of patients must agree to use adequate methods of birth control. Exclusion Criteria: * Prior docetaxel, IPI-504 or other Hsp90 inhibitor treatment * Known hypersensitivity to drugs formulated with polysorbate-80. * Not recovered from any toxicities related to prior treatment * Use of a medication or food that is a clinically relevant CYP3A inhibitor or inducer * Inadequate hematologic function * Inadequate hepatic function * Inadequate renal function * Symptomatic keratitis or keratoconjunctivitis. * Uncontrolled systemic fungal, bacterial, viral or other infection * Patients with clinically active brain metastases * Patients with clinically stable brain metastases (previously treated or untreated) are eligible. * Sinus bradycardia (resting heart rate \<50 bpm). * Significant cardiac disease * Previous or current malignancies at other sites within the last 2 years * Prior hepatic resections or hepatic-directed therapy * Known HIV-positive patients receiving combination antiretroviral therapy. * Women who are pregnant or lactating.