A phase II evaluation of pazopanib in the treatment of recurrent or persistent carcinosarcoma of the uterus: a gynecologic oncology group study

Objective: Carcinosarcomas of the female genital tract, also called malignant mixed müllerian tumors, are aggressive biphasic tumors. Second-line treatment options in the recurrent/persistent setting have yielded marginal responses. Given the potential role of angiogenesis in the gynecological carcinomas, pazopanib, a VEGFR inhibitor, was investigated in the management of patients with recurrent carcinosarcoma of the uterus.

Methods: Eligible patients had histologically confirmed carcinosarcoma of the uterus, a maximum of two prior lines of therapy, adequate renal, hepatic and hematologic function and a performance status of 0-2. Pazopanib was administered orally at 800mg. Two dose reductions were allowed. The primary objective was to ascertain the activity of pazopanib as measured by the proportion of patients who survive progression-free for at least six months and the proportion of patients that have objective tumor responses. Secondary objectives included the frequency and severity of adverse events as assessed by CTCAE v4.0.

Results: Of the 22 enrolled patients, 19 were eligible and evaluable for toxicity and survival. No patients had a partial or complete response (90% confidence interval [CI]: 0%, 14.6%). Three patients (15.8%) had PFS ≥6months (90% CI: 4.4%, 35.9%). The median PFS was 2.0months (first and third quartiles were 1.6 and 4.0months, respectively). The median overall survival was 8.7months (first and third quartiles were 2.6 and 14.0months, respectively).

Conclusion: Pazopanib demonstrated minimal activity as a second or third line treatment for advanced uterine carcinosarcoma. Potential clinical trial participation should be discussed with the patients.