The purpose of this study is to determine whether OSI-211 (Liposomal Lurtotecan) is an effective and safe treatment for patients with recurrent small cell lung cancer.

Inclusion Criteria:

• Confirmed recurrent small cell lung cancer.
• One prior treatment of chemotherapy.
• At least three weeks since last chemotherapy treatment and recovery from any related side effects.
• At least three weeks since last chest radiotherapy and at least 10 days since head irradiation and recovery from acute side effects.
• At least one target tumor less than or equal to 20 mm (or less than or equal to 10 mm on spiral CT-scan).
• If a patient has had previous documented Central Nervous System (CNS) involvement, only controlled disease is acceptable.

Exclusion Criteria:

• Superior vena cava syndrome.