Publication Year: 2000 Visited: 64

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Weekly (W) HerceptinR (H, Traztuximab) and One Hour Taxol (T, Paclitaxel) Infusion (WHT) Regimen for Human Epidermal Growth Factor Receptor-2 (HER2) Overexpressed (+) Metastatic Breast Cancer (MBC). Kai-Yiu Yeung, R. Gupta, D. Haidak, H. Katzen, J. Greer, M. L. Quader, Onc/Hemotology Assoc, Clinton, MD.

HerceptinR, a recombinant humanized monoclonal antibody that targets HER2, has shown a response rate (RR) of 15% as a single agent in 222 patients (pts) with HER2+ MBC who relapsed following chemotherapy (Cobleigh, et al. Proc ASCO 17:Abst 376'98). Combination therapy with Taxol (175 mg/m2/3hr q3wk x 6 cycles) & HerceptinR (2 mg/Kg/wk) markedly increased anticancer activity (RR 57% vs 25%) and time to progression (TTP 7.1 vs 4.2 mo) over Taxol alone as a first-line therapy for HER2+ MBC (Slamon, et al. Proc ASCO 17:Abst 377'98). Dose-dense WHT regimen was piloted at Memorial Sloan-Kettering & MD Anderson Cancer Centers & yielded a RR of 71% in HER2+ MBC (Fornier, et al. Proc ASCO 18:Abst 482'99). We evaluate such regimen in a private practice setting. Regimen: loading dose of HerceptinR, 4mg/Kg on day 1, followed by 2mg/Kg /wk + 1 hour Taxol 80 mg/m2/wk beginning wk 2 until patients showed disease progression or intolerable toxicities. Beginning 11/4/1998, 19 pts were treated with WHT regimen. Median age was 53 (36-83). All pts had prior therapy, including 7 for adjuvant setting, 3 for MBC, and 9 for both. Pts had 0 (5%), 1 (42%), 2 (26%), 3 (11%), 4 (5%), or 5 (11%) prior chemotherapeutic regimens. Seven pts (37%) had prior Taxane treatment. Median number of organ/system involvement was 2. 10 pts (53%) had visceral metastasis. Response included 16% CR, 11% PR, 58% SD, 11% PD, and 5% not evaluable. Median TTP was 23 (5-38) weeks. As of 9/30/1999, we have delivered 474 weeks of WHT. Hematologic toxicities were generally mild. Grade 1/2 anemia occurred in 70%; grade 3/4 leukopenia, 5%; and grade 3/4 infections, 0%. GI toxicities included 26% grade 1/2 diarrhea and 21% grade 1/2 stomatitis. 10 pts (53%) developed peripheral neuropathy and 7 pts (37%) had to discontinue Taxol. In conclusion, dose-dense WHT regimen is a safe and effective regimen for HER2+ MBC that can be comfortably delivered in a private office setting.