Phase II Study of Aerosolized Liposomal 9-Nitro-20 (S)- Camptothecin (L9NC) in Patients With Metastatic or Recurrent Cancer of the Endometrium

RATIONALE: Camptothecin (CPT) is a plant alkaloid isolated from Camptotheca acuminata in 1966. As a topoisomerase I inhibitor, it has powerful anticancer properties and has been used clinically in the treatment of a variety of cancers. It possesses significant toxicity, especially involving the bone marrow and gastrointestinal tract that has limited its use. Derivatives of 20-(S)-camptothecin have been made to increase the aqueous solubility of these compounds and/or modify the A-ring to increase membrane association. The 9-nitrocamptothecin (9-NC) derivative to be used in this study is insoluble in water, but has demonstrated potent antitumor effects in mice and antitumor effect in humans. However, the therapeutic index is low. In order to increase the therapeutic index, a liposomal formulation has been developed, which can be administered as an aerosol. In humans, dose of 0.52 mg/m2/day 5 days per weeks for eight 8 weeks of a 10 week course were well tolerated in the Phase I study. Partial responses were noted in patients with endometrial cancers. The recommended starting dose of L9NC in the Phase II study is 0.52 mg/m2/day to be administered once a day by aerosol (mouth-only breathing) for five consecutive days per week x 8 weeks followed by a 2 week rest. Courses are 10 weeks. This dose corresponds to approximately 1/6 of the MTD of oral 9-NC administered to untreated cancer patients.