This is a single-arm, non-randomized feasibility and Phase I trial of 20(S) Camptothecin Propionate administered orally. CZ48 will be administered in successive cohorts of 1 patient per participating site until hints of toxicity (grade 2 or worse adverse events related to the drug) are observed. Then cohorts of 3+3 patients will be treated. CZ48 will be administered orally daily (1 course = 4 weeks). No pre-medications will be administered. Patients will be asked to drink up to one gallon of fluid daily if possible to flush the bladder to mitigate cystitis. Cystitis is an anticipated toxicity as CZ48 is a pro-drug of CPT (Camptothecin)

PRIMARY OBJECTIVE:

• To describe the dose limiting toxicities and adverse event profile of Camptothecin-20-O-Propionate hydrate (CZ48) administered orally every day for 4 weeks (1 course).

SECONDARYOBJECTIVE

• To determine the Maximum Tolerated Dose (MTD) of Camptothecin-20-O-Propionate hydrate (CZ48).
• To determine the blood plasma levels (PK study) of orally administered CZ48.
• To assess responses by Response Evaluation Criteria in Solid Tumors (RECIST) criteria when applicable.
• To follow patients for survival.

Inclusion Criteria:

• Patients must have a Performance Status (Zubrod) performance status of 0-1
• Patients must sign an informed consent document
• Patients should have adequate bone marrow function defined by an absolute peripheral granulocyte count of > 1,500 /mm3 and platelet count >100,000/mm3 along with an absence of a red blood cell transfusion in the two weeks prior to their participation in the trial
• Patients should have adequate hepatic function with a total bilirubin within normal range and serum glutamate oxaloacetate transaminase (SGOT) or serum glutamate pyruvate transaminase (SGPT) < two times the upper limit of normal (ULN) for patients without liver metastasis and SGOT or SGPT < five times ULN for those with liver metastasis, and adequate renal function as defined by a serum creatinine within 1.5 times the upper limit of normal.
• Patients may receive no other concurrent anticancer treatments such as chemotherapy, hormone therapy (except for prostate cancer patients on luteinizing hormone-releasing hormone ((LHRH)) agonists), immunotherapy, biological agents, investigational agents, or radiation therapy during this trial, and should be off these treatments for at least 2 weeks, or until they have completely recovered from the side effects of these treatments, whichever is longest, except for persistent grade 1 neuropathy in patients who received prior platinum or taxanes.

Exclusion Criteria:

• Patients with symptomatic brain metastases are excluded from this study.
• Patients with brain metastasis that have been treated, asymptomatic and off any steroid use are permitted for study
• Pregnant women or nursing mothers are not eligible for this trial. Patients of child bearing potential must use adequate contraception (contraceptive pill, or intrauterine device ((IUD)), or two mechanical barriers).
• Patients with severe uncontrolled medical problems are not eligible for this trial.
• Patients who have too much esterase as determined by a pre-screen dose, with a conversion rate yielding concentration of CPT > 100 ng/ml in vitro.