A phase II study of a urokinase-derived peptide (A6) in the treatment of persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma: A Gynecologic Oncology Group study

Purpose: This multi-institutional phase II trial assessed the activity and tolerability of the anti-metastatic A6 peptide that binds CD44 in patients with persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma (EOC/FTC/PPC). Patients and methods: Women with persistent or recurrent EOC/FTC/PPC were eligible for participation if they had measurable disease defined by RECIST criteria, good performance status, and good overall organ function. Patients must have received one prior platinum-based chemotherapeutic regimen and were allowed to have received one additional cytotoxic regimen for the management of recurrent or persistent disease. Women received a 150 mg twice daily subcutaneous dose of A6 and continued on treatment until disease progression or unacceptable toxicity. Primary measures of clinical efficacy were objective tumor response and progression-free survival (PFS) at 6 months. The association of CD44 in archival tissue specimens with clinical outcome was investigated. Results: Thirty-one eligible patients were evaluated. No responses were observed. Two patients (6.5%) were progression free for at least 6 months. The median PFS was 2.0 months, and median overall survival has not yet been reached. One patient died of hemorrhage which was possibly study related. There were no grade 4 toxicities. The most common grade 3 toxicities were constitutional (2/31; 6.5%). Archival specimens were available for 27 patients, and 5 (18.5%) were CD44 positive by immunohistochemistry. CD44 expression was not associated with the 6-month PFS (p = 0.342). Conclusion: A6 was well tolerated but had minimal activity in patients with persistent or recurrent EOC/FTC/PPC.