Researchers from Israel reported that Tykerb® (lapatinib) monotherapy provides significant response rates among women with HER2-positive, recurrent inflammatory breast cancer (IBC), even among those refractory to Herceptin® (trastuzumab). These results were recently reported at the 2008 annual meeting of the American Society of Clinical Oncology (ASCO).

Inflammatory breast cancer is associated with a significantly poorer prognosis than non-IBC with the given standard therapeutic approaches. Because only approximately 2-6% of breast cancers are IBC, difficulty remains in the enrollment of a sufficient number of patients for clinical trials evaluating novel therapeutic approaches for IBC. Researchers from Israel reported data on the largest prospective trial ever conducted in HER2-positive IBC at this year’s ASCO. The trial included 126 patients with HER2-positive IBC refractory to anthracyclines, taxanes, and Herceptin (where available) who were treated with Tykerb 1,500 mg daily. RECIST-measurable disease was assessed every eight weeks, and skin lesions were assessed every four weeks.

• The overall response rate was nearly 39%.
• 36% of Herceptin-refractory patients achieved a response to Tykerb.
• The median duration of response was nearly 21 weeks.
• Overall progression-free survival was 14.6 weeks.
• Diarrhea occurred in approximately 60% of patients and was the most common toxicity.
• The most common serious adverse events were dyspnea, occurring in 6% of patients; pleural effusion, occurring in 4% of patients; and pyrexia, occurring in 2% of patients.

Comments: These data support previous data suggesting high activity for Tykerb for the treatment of refractory HER2-positive IBC.

Related News:

Tykerb® Effective in Inflammatory Breast Cancer (12/20/2006)

10-Year Survival of Patients With Localized Inflammatory Breast Cancer Reported (11/01/2006)

Phase II Trial Suggests that Tykerb® is Active in Inflammatory Breast Cancer (06/05/2006)

Reference: Kaufman B, Trudeau M, Johnston S, et al. Clinical activity of lapatinib monotherapy in patients with HER2+ relapsed/refractory inflammatory breast cancer (IBC): Final results of the expanded HER2+ cohort in EGF103009. Proceedings from the 2008 annual meeting of the American Society of Clinical Oncology (ASCO). Abstract #636.