Lapatinib Shows Anti-Tumour Activity in Herceptin® - Resistant Breast Cancer Patients
Sunday June 6, 1:45 pm ET
Interim Phase II Trial Results Presented at American Society of Clinical Oncology (ASCO Abstract #2339)
LONDON and PHILADELPHIA, June 6 /PRNewswire-FirstCall/ -- GlaxoSmithKline (NYSE: GSK; LSE) today announced interim results of a once-daily oral dose of lapatinib (GW572016) from a Phase II clinical study presented today at the 40th Annual Meeting of the American Society of Clinical Oncology (ASCO). Objective response or stable disease (lasting 8 to 16 weeks) were reported in 46 percent of women (scheduled interim analysis, first 41 patients on study) with heavily pretreated advanced metastatic breast cancer whose disease had previously progressed on trastuzumab (Herceptin*) containing regimens (including chemotherapy, hormones, etc), according to interim results. The study was designed to determine tumour response rate and tolerability in patients who received lapatinib, which targets two receptors (ErbB1 or EGFR and ErbB2) after these patients had progressed on Herceptin, a single receptor (ErbB2) inhibitor. Lapatinib does not have regulatory approval in any country for use in any indication.
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"The evidence that we could stabilise or shrink tumours in some women whose disease progressed following treatment with Herceptin was encouraging and suggests that simultaneous targeting of both ErbB1 and ErbB2 may represent a new approach in the treatment in breast cancer," said Kimberly L. Blackwell, M.D., Assistant Professor of Medicine, Department of Medicine, Division of Hematology/Oncology, at Duke University Medical Centre, who presented the study. "Research into new treatment options for women with metastatic breast cancer is bringing us closer to a day when we can halt the progress of this cancer and manage it like other chronic diseases."
The multi-centre, open-label study of women with ErbB2 overexpressing metastatic breast cancer that had progressed on Herceptin-containing regimens was conducted to assess the clinical response and toxicity of monotherapy with a planned daily 1500 mg oral dose of lapatinib. These heavily pre-treated patients received lapatinib until their disease progressed and were evaluated at eight-week intervals while on treatment.
As reported at ASCO, interim data, were presented on the first 41 patients. The results indicate that 46.3 percent (19 patients) had either a partial response or stable disease at 8 weeks and 24.4 percent (10 patients) were progression-free at 16 weeks, with follow-up continuing. The trial will continue to accrue to a total of 80 patients.
The most frequently reported adverse events were rash, fatigue and diarrhoea, with Grade 3 events reported for rash (5%), fatigue (5%) and diarrhoea (10%). One patient had a Grade 2 decrease in left ventricular ejection fraction that resolved with continued treatment (the effect was asymptomatic and transient). One Grade 4 adverse event (respiratory failure) was observed but there was no association with the study drug, according to the investigator.
Lapatinib is currently under investigation in a variety of solid tumours and Phase III trials have been initiated in a target indication for metastatic breast cancer.
About Lapatinib
Lapatinib is a potent, reversible inhibitor of ErbB1 and ErbB2, which are members of a receptor tyrosine kinase family comprised of four closely related receptors (ErbB1 to ErbB4). Overexpression of ErbB1 and ErbB2 has been reported in a variety of human tumours and is associated with poor prognosis and reduced overall survival. Moreover, stimulation of these receptors is associated with cell proliferation, and with multiple processes involved in tumour progression, invasion and metastasis. Lapatinib is a small molecule that targets the ErbB1 and ErbB2 receptors.
To find out more about ongoing clinical trials of lapatinib in breast cancer go to
http://www.4BreastCancerTrials.com or call 800-563-7137. Information about these trials is also available at
http://www.clinicaltrials.gov (keyword: GW572016), a website maintained by the U.S. government, or by calling the National Cancer Institute's Cancer Information Service at 1-800-4-CANCER.
About Metastatic Breast Cancer
The World Health Organisation reports that in 2004 more than 1 million cases of breast cancer will be diagnosed and an estimated 40,580 will die from the disease. Breast cancer is the most common malignancy in women and one of the leading causes of cancer death. Approximately 40 percent of breast cancer patients develop metastatic breast cancer (disease that has spread to other organs) after receiving treatment during the primary breast cancer phase and the average survival time for patients after diagnosis of metastatic disease is 18 to 30 months.
The economic impact, social consequences, and overall morbidity and mortality of breast cancer are devastating, making the search for new effective treatments a high priority. Despite advances over the past several decades, metastatic breast cancer remains a significant therapeutic challenge. The majority of patients with metastatic breast cancer treated with Herceptin- containing regimens eventually experience disease progression. The response rate to salvage chemotherapy is as low as 11 percent.
About GlaxoSmithKline
GlaxoSmithKline -- one of the world's leading research-based pharmaceutical and healthcare companies -- is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For company information, visit GlaxoSmithKline at
http://www.gsk.com.
Herceptin® is a registered trademark of Genentech.
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