Phase II trial of GM-CSF in women with asymptomatic recurrent müllerian tumors.

Objective: GM-CSF is a recombinant human cytokine, which promotes the proliferation and differentiation of granulocytes and monocytes, and is associated with anti-tumor activity. The primary objective was to define the median time to treatment termination (TTT) with women with relapsed ovarian cancer treated with single agent GM-CSF delivered subcutaneously (SC).

Patients And Methods: Open label phase II study in asymptomatic patients with recurrent müllerian malignancy without an indication for immediate systemic chemotherapy. In the first cohort of 35 women, GM-CSF 250 microg/m(2) was administered SC on days 1-14 of a 28-day cycle, the second cohort received continuous GM-CSF 150 microg/m(2) given with dose escalation.

Results: Seventy-two women were enrolled. Best overall response included one complete response, and 20 patients with stable disease (23%), 4 of whom had stable disease for >6 months. Median TTT was 78 days. Toxicity in both cohorts was generally mild; however, four patients experienced excessive toxicity and withdrew consent. In the first cohort, CA-125 dropped in 70% of women from their baseline on study value (median change -23%, range -48 to +116%) after 14 days of GM-CSF. The magnitude of CA-125 drop during the first 2 weeks of therapy also showed a positive inverse correlation with day 15 white cell count for the whole group (p=0.038).

Conclusion: GM-CSF is well tolerated and frequently associated with a decline in CA-125 that is correlated with leukocytosis. Although median TTT is modest, a subset of women had prolonged stable disease.