Inclusion Criteria:

- Pathologically documented NSCLC

- Locally advanced (Stage III) or metastatic (Stage IV) NSCLC

- Only one prior anti-tumor treatment regimen in the non-curative setting (i.e.,
2nd-line therapy)

- Only one prior anti-tumor treatment regimen in the curative setting

- Progressive disease following the previous anti-tumor treatment regimen

- Measurable disease by RECIST criteria

- Brain metastasis must be stable and well-controlled

ECOG performance score 0-2All anti-tumor therapy discontinued at least 3 weeks prior to
study entryAll adverse events from prior treatment are resolved or stableAdequate
hematologic, renal, and hepatic functionFemales must not be pregnantWilling to take
adequate measures to prevent pregnancyLife expectancy of at least 3 monthsAble to complete
the Quality of Life questionnaireVoluntarily signed informed consent

- Only one prior anti-tumor treatment regimen in the curative setting

- Progressive disease following the previous anti-tumor treatment regimen

- Measurable disease by RECIST criteria

- Brain metastasis must be stable and well-controlled

- ECOG performance score 0-2

- All anti-tumor therapy discontinued at least 3 weeks prior to study entry

- All adverse events from prior treatment are resolved or stable

- Adequate hematologic, renal, and hepatic function

- Females must not be pregnant

- Willing to take adequate measures to prevent pregnancy

- Life expectancy of at least 3 months

- Able to complete the Quality of Life questionnaire

- Voluntarily signed informed consent

Exclusion Criteria:

- Greater that Grade 1 neurological findings

- Allergy to sulfa medications

- Previous treatment with ABT-751 or docetaxel

- Receipt of more than one investigational agent for NSCLC

- Significant weight loss (>10%) within 6 weeks of study entry

- Glucose-6-phosphate dehydrogenase deficiency or porphyria

- Significant systemic disease that would adversely affect participation

- Class 3-4 New York Heart Association classification status

- Other cancers except in situ carcinoma of the cervix, basal or squamous cell skin
cancer, or any other cancer considered adequately treated and cured by the
investigator