Study of AT-101 in Combination With Topotecan in Relapsed/Refractory Small Cell Lung Cancer

Inclusion Criteria:

* Histologically or cytologically confirmed small cell lung cancer (SCLC). Mixed histology will not be eligible.
* Progression of disease after only one prior platinum containing chemotherapy regimen. Prior Regimen must not have contained irinotecan
* All patients must have measurable disease.
* Patients may have received prior radiation therapy but they must have recovered from all treatment-related toxicities.
* ECOG performance status 0-1
* Adequate hematologic function
* Adequate liver and renal function
* Ability to swallow oral medication

Exclusion Criteria:

* Patients with more than one prior regimen of chemotherapy or prior regimen that did not contain a platinum agent. Note: Patient who stopped prior therapy due to toxicity or had less than 2 cycles of platinum based therapy would not be eligible for the phase II portion of this study.
* Prior chemotherapy regimen containing irinotecan.
* Active secondary malignancy.
* Unstable or progressive brain metastases.
* Prior history of radiation therapy to \> 25% of the bone marrow.
* Uncontrolled concurrent illness including, but not limited to: serious uncontrolled infection, symptomatic congestive heart failure (CHF), unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with the study requirements.
* Failure to recover from toxicities related to prior therapy (e.g., surgery, radiation, chemotherapy).