Table 4 Clinical trials of ixabepilone in drug-resistant metastatic breast cancer
From: Chemotherapy resistance in metastatic breast cancer: the evolving role of ixabepilone
Study | Population | Evaluable for efficacy/enrolled | Pretreatment characteristics | Activity |
|---|---|---|---|---|
Ixabepilone monotherapy | ||||
Trial 009, phase II [88] | Resistant to taxane; prior treatment with anthracycline-based regimena | 49/49 | All had received ≥1 prior taxane-based regimen (31 % had ≥2 regimens); 98% had a taxane-containing regimen as their most recent MBC therapy, and 73% had progressed within 1 month of the last administered taxane dose | ORR 12%; 41 % stable disease Median DOR 10.4 months Median TTP 2.2 months (95% CI, 1.4 to 3.2 months) Median OS 7.9 months (95% CI, 6.1 to 14.5 months) |
Trial 081, phase II [89] | Resistant to an anthracycline, a taxane, and capecitabine | 113/126 | 77% with visceral disease in liver and/or lung; 88% had completed ≥2 prior chemotherapy regimens for MBC, 48% had ≥3 lines | ORR 11.5%; 50% stable disease Median DOR 5.7 months (95% CI, 4.4 to 7.3 months) Median PFS 3.1 months (95% CI, 2.7 to 4.2 months) Median OS 8.6 months (95% CI, 6.9 to 11.1 months) |
Ixabepilone/capecitabine combination | ||||
Trial 031, phase II [90] | Anthracycline-pretreated or resistant and taxane-resistantb | 50/62 | 72% had baseline visceral metastases, 43% had ≥2 prior chemotherapy regimens in the metastatic setting for MBC | ORR 30%c; 32% stable disease Median time to response 6 weeks (range, 5 to 14 weeks) Median DOR 6.9 months (95% CI, 4.3 to 9.7 months) |
Trial 046, phase III [92] | Pretreated with or resistant to anthracyclines and resistant to taxanesd | 737/752 | 65% had ≥3 metastatic disease sites; 48% had received ≥1 prior regimen for MBC; 85% had progressed on prior taxane therapy for metastatic disease | ORR 34.7% vs. 14.3% Median DOR 6.4 months vs. 5.6 months Median PFS 5.8 months vs. 4.2 months; hazard ratio = 0.75 (95% CI, 0.64 to 0.88)e |