Davidson, Nancy E.

Purpose To determine whether a matrix metalloproteinase inhibitor improves progression-free survival (PFS) in patients with metastatic breast cancer who have responding or stable disease after first-line chemotherapy. Patients and Methods One hundred seventy-nine eligible patients were randomly assigned to receive oral marimastat (10 mg bid; n = 114) or a placebo (n = 65) within 3 to 6 weeks of completing six to eight cycles of first-line doxorubicin- and/or taxane-containing chemotherapy for metastatic disease. Patients were evaluated every 3 months until disease progression. Results When comparing placebo with marimastat, there was no significant difference in PFS (median, 3.1 months v 4.7 months, respectively; hazard ratio, 1.26; 95% CI, 0.91 to 1.74; P = .16) or overall survival (median, 26.6 months v 24.7 months, respectively; hazard ratio, 1.03; 95% CI, 0.73 to 1.46; P = .86). Patients treated with marimastat were more likely to develop grade 2 or 3 musculoskeletal toxicity (MST), a known complication of the drug indicative of achieving a biologic effect, compared with patients administered placebo (63% v 22%, respectively; P < .0001). Patients with grade 2 or 3 MST had significantly inferior survival compared with patients who had grade 0 or 1 MST (median, 22.5 months v 28.2 months; P = .04). In addition, patients who had a marimastat plasma concentration of at least 10 ng/mL at month 1 and/or 3 were significantly more likely to have grade 2 to 3 MST (P < .0001). Conclusion Marimastat does not prolong PFS when used after first-line chemotherapy for metastatic breast cancer. Patients with higher marimastat levels exhibited MST, and MST was associated with inferior survival.

Purpose To evaluate changes in left ventricular ejection fraction (LVEF) after four cycles of adjuvant doxorubicin plus cyclophosphamide (AC) in women with human epidermal growth factor receptor 2–positive (node-positive or node-negative) breast cancer enrolled onto the North Central Cancer Treatment Group N9831 Intergroup Adjuvant Trial. Patients and Methods Patients were randomly assigned to receive standard doxorubicin (60 mg/m2) plus cyclophosphamide (600 mg/m2) every 3 weeks for four cycles followed by (1) weekly paclitaxel for 12 weeks; (2) weekly paclitaxel for 12 weeks, then weekly trastuzumab for 52 weeks; or (3) weekly paclitaxel plus trastuzumab for 12 weeks, then weekly trastuzumab for 40 weeks. LVEF was monitored before and after AC. Results Of the 1,576 eligible patients who completed AC, 1,458 had pre- and post-AC LVEF measurements taken using the same methodology (multiple-gated acquisition in 1,153 patients and echocardiogram in 305 patients). Among these 1,458 patients, 745 (51.1%) had ≤ 15% decrease in LVEF and LVEF that remained at or above the radiologic lower limit of normal (LLN); 42 patients (2.9%) had ≤ 15% decrease in LVEF and LVEF that decreased to or below the LLN; and 37 patients (2.5%) had an LVEF decrease of more than 15%. There was grade 2 LVEF toxicity in 96 (6.6%) of the 1,458 patients. Conclusion Standard AC chemotherapy is associated with frequent decreases in LVEF, which are noted when measured 3 weeks after completion of the fourth cycle. Patients are being observed to determine the long-term significance of this and the potential impact on subsequent treatment options.