The purpose of this study is to determine the bioequivalence of the new oral capsule formulation to the currently used oral capsule formulation of topotecan.

Inclusion Criteria:

• Subjects with advanced solid tumors.
• At least 4 weeks since last chemotherapy, radiotherapy, biologic therapy or surgery.
• Subjects must be free of post-treatment side effects.

Exclusion Criteria:

• Women who are pregnant or lactating
• Subjects with uncontrolled emesis, regardless of etiology, active infection.