The arrival of new cancer drug Tyverb to UK shores aims to give hope to women suffering from metastatic breast cancer who no longer respond to Herceptin (trastuzumab) treatment.
Developed by GlaxoSmithKline, the new oral treatment - Lapatinib, targets the aggressive and fast-growing ErbB2-positive disease. But unlike trastuzumab, the treatment is a small molecule, which can penetrate the cancer cell, allowing it to act on the intracellular part of the receptors to block the pathways that stimulate cancer cell proliferation and survival.1
Most women with ErbB2-positive advanced breast cancer, who initially respond to trastuzumab and chemotherapy, will relapse within one year. Until now, there were no further licensed ErbB2-targeted therapy options available.2,3
"Lapatinib, taken with capecitabine, is an important development in the treatment of the more aggressive, ErbB2-positive breast cancer, which affects approximately 20-25% of women with breast cancer and has a poor prognosis," said Dr Andrew Wardley, consultant medical oncologist at the Christie Hospital in Manchester and lapatinib clinical trialist. "This combination significantly increases the time that these patients" breast cancer is kept under control, compared with capecitabine given on its own. An extra few weeks is clinically meaningful at this stage of the disease. Lapatinib has been specifically designed to target the receptors inside the cancer cell and, with the convenience of being an oral treatment, is a useful new treatment at our disposal to manage advanced disease."
Lapatinib has a conditional licence for use in combination with capecitabine (Xeloda), for ErbB2-positive advanced breast cancer, following treatment with anthracyclines, taxanes, and trastuzumab for metastatic disease.4
Lapatinib's licence is based on this pivotal trial involving 399 women with ErbB2-positive advanced breast cancer, whose disease had progressed following prior treatment with anthracyclines, taxanes, and trastuzumab for advanced disease. 5
Lapatinib's licence is conditional, pending further clinical data, including an investigation into its potential effect on reducing the incidence of brain metastases. This is one of the most common sites of relapse in ErbB2-positive breast cancer.6
"In the UK, over 320 eligible patients have already been treated with Tyverb, in combination with capecitabine, via an expanded access programme. We are pleased that women with ErbB2-positive advanced breast cancer, whose disease has progressed following trastuzumab, now have a new treatment option," said Simon Jose, General Manager, GSK UK. He added: The launch of lapatinib as an oral combination with capecitabine, gives patients the benefit of having their treatment at home."
References
1. Johnston SRD, Leary A. Lapatinib: A novel EGFR/HER2 tyrosine kinase inhibitor for cancer. Drugs of Today 2006; 42 (7): 441-453.
2. Slamon DJ, Clark GM, Wong SG, et al. Human Breast Cancer. Correlation of relapse and survival with amplification of the HER2/neu oncogene. Science 1987; 235: 177-182.
3.Marty M, Cognetti F, Maraninchi D, et al .Randomized phase II trial of the efficacy and safety of trastuzumab combined with docetaxel in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer administered as first-line treatment: the M77001 study group. J Clin Oncol. 2005; 23: 4265-74.
4.Tyverb (lapatinib) Summary of Product Characteristics.
6.Lin NU, Bellon JR, Winer EP. CNS metastases in breast cancer. J Clin Oncol 2004; 22: 3608-3617.