Inclusion Criteria:

- Histological or cytological diagnosis of SCLC at study entry according to the
International Association for the Study of Lung Cancer (IASLC) histopathologic
classification. Mixed or combined subtypes according to the IASLC are not allowed;

- SCLC that is either sensitive (defined as a response including stable disease to
first-line platinum-based chemotherapy, with subsequent progression >/= 90 days after
completing first-line chemotherapy) or refractory (defined as best response to
first-line platinum-based chemotherapy or progression < 90 days after completing
first-line chemotherapy);

- Extensive or limited disease; patients with limited disease who are candidates for
local or regional salvage radiation therapy must have been offered such treatment
prior to participation in this study;

- Radiographically documented progression after first-line treatment with
platinum-based chemotherapy;

- No more than 1 prior chemotherapy regimen;

- At least 18 years of age;

- ECOG performance status of 0 - 1

Exclusion Criteria:

- Chest radiotherapy with curative intent to the primary disease complex prior to first dose; CNS radiotherapy to all other areas
- Prior anthracycline, topotecan, or irinotecan treatment.

- Prior anthracycline or topotecan treatment.

- Patients with know history of seropositive human immunodeficiency virus (HIV) or
patients who are receiving immunosuppressive medications that would increase the risk
of serious neutropenic complications