Inclusion Criteria:

1. Men or women 18 years of age or older
2. Must have Non-small Cell Lung Cancer with ALK+ mutation or other mutations or rearrangements potentially sensitive to crizotinib
3. Measurable disease
4. Must have been receiving or have received crizotinib
5. Have adequate cardiac, bone marrow, liver and kidney function
6. Must be willing and able to provide written informed consent and comply with the protocol and study procedures 

Exclusion Criteria:

1. Prior anti-cancer treatment with any HSP90 inhibitor
2. Have received chemotherapy, radiation therapy or other anticancer treatment other than crizotinib within 3 weeks prior to the first dose of study drug
3. Prior malignancy other than adequately treated basal or squamous cell carcinoma of the skin, superficial bladder cancer, low-grade cervical cancer, non-metastatic prostate cancer, or have been disease-free for at least 3 years
4. Abnormal heart function
5. Presence of a life-threatening illness, medical condition, organ system dysfunction, or other factors
6. Hypersensitivity of AT13387 or other components of the drug product
7. Treatment with an investigational drug within 3 weeks prior to the first dose of study drug
8. Severe systemic diseases or active uncontrolled infections
9. Known history of human immunodeficiency virus (HIV) or seropositive test for hepatitis C virus or hepatitis B virus