PRIMARY OBJECTIVE:~I. To estimate the overall tumor response rate (overall response rate [ORR], that is, complete response [CR] + partial response [PR], according to Response Evaluation Criteria in Solid Tumors version 1.1 [RECIST v1.1] of PLX038 in the setting of metastatic platinum resistant high grade serous ovarian cancer.~SECONDARY OBJECTIVES:~I. To estimate the progression-free survival and overall survival of treatment with PLX038.~II. To describe and assess tolerability of PLX038. III. Measure PLX038 induced tumor TOP1-deoxyribonucleic acid (DNA) covalent complexes (TOP1cc) in pretreatment and Cycle 1 Day 8 biopsies to confirm persistent stabilization of TOP1cc and evaluate association with tumor response rate.~CORRELATIVE RESEARCH:~I. Measure TOP1cc in circulating tumor cells and evaluate association with TOP1cc in tumor tissue and tumor response rate.~II. Assess homologous repair status and association with tumor response. III. Assess expression of SN-38 transports by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and association with tumor response.~OUTLINE:~Patients receive PLX038 intravenously (IV) over 1 hour on day 1 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up at 30 days and every 6 months for up to 5 years.
This phase II trial tests whether pegylated SN-38 conjugate PLX038 (PLX038) works to shrink tumors in patients with ovarian, primary peritoneal, and fallopian tube cancers that has spread to other places in the body. PLX038 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.