14 CLINICAL STUDIES
The ability of ZINECARD to prevent/reduce the incidence and severity of doxorubicin-induced cardiomyopathy was evaluated in three prospectively randomized placebo-controlled studies. In these studies, patients were treated with a doxorubicin-containing regimen and either ZINECARD or placebo starting with the first course of chemotherapy. There was no restriction on the cumulative dose of doxorubicin. Cardiac function was assessed by measurement of the LVEF, utilizing resting multigated nuclear medicine (MUGA) scans, and by clinical evaluations. Patients receiving ZINECARD had significantly smaller mean decreases from baseline in LVEF and lower incidences of congestive heart failure than the control group; however, in the largest study, patients with advanced breast cancer receiving FAC with ZINECARD had a lower response rate (48% vs. 63%) and a shorter time to progression than patients who received FAC versus placebo.
In the clinical trials, patients who were initially randomized to receive placebo were allowed to receive ZINECARD after a cumulative dose of doxorubicin above 300 mg/m2. Retrospective historical analyses showed that the risk of experiencing a cardiac event (see Table 3 for definition) at a cumulative dose of doxorubicin above 300 mg/m2 was greater in the patients who did not receive ZINECARD beginning with their seventh course of FAC than in the patients who did receive ZINECARD (HR=13.08; 95% CI: 3.72, 46.03; p<0.001). Overall, 3% of patients treated with ZINECARD developed CHF compared with 22% of patients not receiving ZINECARD.
Figure 1 shows the number of patients still on treatment at increasing cumulative doses.