Objective. Following a reported 23%response rate (RR) for mitomycin (M), doxorubicin (A), and cisplatin (P) and preliminary data suggesting a superior RR for dacarbazine (D) +MAP +sargramostim, the Gynecologic Oncology Group (GOG) conducted a phase II trial of DMAP +sargramostim in patients with advanced uterine leiomyosarcoma. Methods. Eligibility required measurable disease, a GOG performance score of 0-2, and recovery from surgery/radiotherapy. Treatment consisted of sargramostim 250 μg/m2 SC q 12 h days -6 through -3, followed by D 750 mg/m2 IV over 2 h, M 6 mg/m2 IV, A 40 mg/m2 IV and P 60 mg/m2 IV over 2 h on day 1, followed by sargramostim 250 μg/m2 SC days 2-15. Cycles were repeated q 28 days (if ANC ≥1500/μl and platelets ≥100,000/μl) until disease progression or toxicity prevented further therapy. Doses were to be reduced by 20%for grade 4 neutropenia >7 days or any grade 4 thrombocytopenia and by 10%for a 1-to 2-week treatment delay for myelosuppression. Results. One of 19 patients who entered the study was ineligible. Eighteen patients received a median of 3.5 cycles (range: 1-6 cycles) of therapy. The overall RR was 27.8%(5.6%complete and 22.2%partial responses). Percent of patients with grade 3 or 4 toxicities included 78%neutropenia, 94%thrombocytopenia, 61%anemia, 44%GI, 28%infection, and 17%azotemia. Conclusions. DMAP +sargramostim produced a 27.8%RR, but its complexity and toxicity precluded further investigation, and the study was closed after the first stage of accrual. Objectives. Following a reported 23% response rate (RR) for mitomycin (M), doxorubicin (A), and cisplatin (P) and preliminary data suggesting a superior RR for dacarbazine (D) + MAP + sargramostim, the Gynecologic Oncology Group GOG) conducted a phase II trial of DMAP + sargramostim in patients with advanced uterine leiomyosarcoma. Methods. Eligibility required measurable disease, a GOG performance score of 0-2, and recovery from surgery / radiotherapy. Treatment consisted of sargramostim 250 μg / m2 SC q 12 h days -6 through -3, followed by D 750 mg / m2 IV over 2 h, M 6 mg / m2 IV, A 40 mg / m2 IV and P 60 mg / m2 IV over 2 h on day 1, followed by sargramostim 250 μg / m2 SC days 2-15. Cycles were repeated q 28 days (if ANC ≥ 1500 / μl and platelets ≥ 100,000 / μl) until disease progression or rate of 30% grade 4 neutropenia> 7 days or any grade 4 thrombocytopenia and by 10% for a 1-to 2-week treatment delay for myelosuppression. Results. One of 19 patients who entered the study was ineligible. Eighteen patients received a median of 3.5 cycles (range: 1-6 cycles) of therapy. The overall RR was 27.8% (5.6% complete and 22.2% partial responses). Percent of patients with Grade 3 or 4 toxicities included 78% neutropenia, 94% thrombocytopenia, 61% anemia, 44% GI, 28% infection, and 17% azotemia. Conclusions. DMAP + sargramostim produced a 27.8% RR, but its complexity and toxicity precished further investigation , and the study was closed after the first stage of accrual.