Tozaride

There are two parts to this trial. The first study will evaluate increasing doses of Re188 P2045 in patients with advanced small cell lung cancer that has recurred after initial therapy or in patients with other advanced neuroendocrine cancers that have progressed after therapy.
Re188 P2045 is designed to attach to type 2 somatostatin receptors that are frequently expressed in those cancers and then the radioactivity from Re188 will kill the cancer cell. Only patients who have cancers that can be seen when Tc99 P2045 is administered (also seeks out the SSTR2, but Tc99 images, but does not treat the cells) will be treated.
Therefore, this approach maximizes the possibility that patients will benefit from treatment in that only those who have cancers that have the target will undergo treatment. The primary purpose of this study will be to determine the highest dose of Re188 P2045 that can be safely administered.
The second study will open after the conclusion of the first. Patients will first undergo the scan with Tc99 P2045 and then be treated with topotecan for three days. Topotecan is a standard chemotherapy drug that is approved for second line therapy for small cell and frequently used for other neuroendocrine cancers. Following that, patients will then be re-evaluated with the Tc99 P2045 scan and if it demonstrates that the tumor is positive for SSTR2, then patients will receive Re188 P2045. The goal of this study is to determine the highest dose of Re188 P2045 that can be safely administered after topotecan as well as to determine if topotecan will increase the chance that the tumor will express SSTR2.