First-line Herceptin (R) monotherapy in metastatic breast cancer

The pivotal phase II and III Herceptin (R) trials proved the efficacy and s afety of second- or third-line single-agent Herceptin and first-line Hercep tin in combination with chemotherapy, respectively. In the current trial, 1 14 patients were randomized to one of two dose groups of first-line Hercept in monotherapy: standard dose of 4 mg/kg initial dose followed by 2 mg/kg i ntravenous (i.v.) weekly; or high dose of 8 mg/kg initial dose followed by 4 mg/kg im. weekly. The regimen was generally well tolerated. A similar inc idence of adverse events was demonstrated in the two dose groups with the p ossible exception of acute infusion-related events such as fever and chills as well as rash and dyspnea, which appear to be more prevalent in the high er dose group. The overall response rate was 26% and response rates were si milar between the two dose groups (24% for the standard Herceptin dose grou p and 28% for the high Herceptin dose group). Subgroup analysis determined a higher response rate in IHC 3+ patients (35%) and FISH-positive patients (41%). When women with stable disease for greater than or equal to6 months were included with responders, the clinical benefit rate in IHC 3+ patients was 47%. Median survival was 24.4 months, which is comparable with the sur vival rate seen in the pivotal phase Ill combination trial (25 months). The refore, single-agent Herceptin is an important new option for the first-lin e treatment of HER2-positive metastatic breast cancer patients. Copyright ( C) 2001 S. Karger AG, Basel.