PLX038 (PEGylated SN38) and Rucaparib in Solid Tumors and Small Cell Cancers

Background: Drugs known as poly-adenosine diphosphate ribose polymerase (PARP) inhibitors are known to help stop tumor growth in patients with breast, ovarian cancers and many other cancers including prostate and pancreatic cancers. Many research studies done in animals and human cells have shown that these types of drugs can improve how well chemotherapy works. Standard chemotherapy can be too toxic to be combined with PARP inhibitors. In this study, we use a new form of chemotherapy called PLX038 (PEGylated SN38) to see if it can be safely combined with PARP inhibitors to shrink tumors. Objective: To find a safe combination of PLX038 and rucaparib, and to see if this mix will cause tumors to shrink. Eligibility: People age 18 and older with solid tumors, small cell lung cancer (SCLC), or small cell cancer outside their lungs. Design: Participants will be screened with: Physical exam Blood tests Records of their diagnosis (or they will have a tumor biopsy). A review of their symptoms and medications. A review of their ability to perform their normal activities. Electrocardiograms, to measure the electrical activity of the heart. Computed tomography (CT) scans of the chest, abdomen, and pelvis. CT scans are a series of X-rays. Participants will get PLX038 by intravenous catheter on Day 1 of each cycle (1 cycle = 21 days). For this, a small plastic tube is put into an arm vein. They will take rucaparib twice daily by mouth on Days 3 to 19 of each cycle. They will keep a medicine diary. Participants may give a hair sample. They may have optional tumor biopsies. Screening tests are repeated throughout the study. About 30 days after treatment ends, participants will have a safety follow-up visit. They will give blood samples, talk about their health, and get a physical exam. Then they will be called or emailed every 6 months....

* INCLUSION CRITERIA: * Subjects with: * histologically confirmed solid tumors (Phase I), OR * histologically or cytologically confirmed small cell lung cancer (SCLC) (Phase II), OR * histologically or cytologically confirmed extra-pulmonary small cell carcinomas (Phase II). * Age greater than or equal to 18 years. Because no dosing or adverse event data are currently available on the use of PLX038 (PEGylated SN38) in combination with rucaparib in participants \