Lapatinib Effective for Inflammatory Breast Cancer: Presented at SABCS

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Lapatinib Effective for Inflammatory Breast Cancer: Presented at SABCS

By Charlene Laino

SAN ANTONIO, TX -- December 14, 2006 -- The small-molecule tyrosine kinase inhibitor lapatinib appears to be effective for the treatment of women with aggressive, inflammatory breast cancer, a prospective phase 2 study suggests.

Massimo Cristofanilli, MD, associate professor, department of breast medical oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, reported the findings here on December 14th at the 29th Annual San Antonio Breast Cancer Symposium (SABCS).

Dr. Cristofanilli and colleagues enrolled 35 women who were a median of 53 years of age and diagnosed with previously untreated inflammatory breast cancer. The women were divided into 2 groups: cohort A included 30 women whose tumors overexpressed human epidermal growth factor receptor 2 (HER2); cohort B included 5 women whose tumors were epidermal growth factor receptor (EGFR)-positive but who did not overexpress human epidermal growth factor receptor 2 (HER2).

All patients were given 1,500 mg of lapatinib daily for 14 days, followed by 3 months of 1,500 mg of lapatinib daily plus 80 mg/m2 of paclitaxel for 12 weeks. At the end of this treatment period, all patients were referred for surgery.

The study's results showed that 77% of patients in cohort A responded to lapatinib, with 10% achieving a complete response and 67% a partial response. In Cohort B, 80% of patients had a partial response and none had a complete response.

Of the 21 patients who completed surgery at data analysis, 14% had a pathologic complete response -- all of them in cohort A. Dr. Cristofanilli noted that pathological complete response is "a strong prognostic factor for improved outcomes."

Lapatinib was generally well tolerated, he said, with only 1 patient discontinuing treatment due to toxicity. The most common grade 3 toxicity was diarrhea, observed in 60% patients.

"In summary, lapatinib is clinically active in the neoadjuvant treatment of HER2-positive breast cancer," he said. "We strongly believe it provides new hope to the patient with inflammatory breast cancer."

The research was supported by GlaxoSmithKline, which is developing lapatinib under the trade name Tykerb.


[Presentation title: A Phase II Combination Study of Lapatinib and Paclitaxel as a Neoadjuvant Therapy in Patients With Newly Diagnosed Inflammatory Breast Cancer (IBC). Abstract 1]