Lapatinib clinical trial update

Issued: London UK

A planned interim review of early data from ALTTO a Phase III, four arm study of adjuvant lapatinib (Tykerb/Tyverb^®), trastuzumab, their sequence and their combination in patients with HER2 positive early stage breast cancer, has resulted in a change to the ongoing study. The independent data monitoring committee that carried out the review has recommended that three of the trial arms continue without modification. However, the committee has indicated that the lapatinib alone arm is unlikely to meet the pre-specified criteria to demonstrate non-inferiority to trastuzumab alone with respect to disease-free survival.  Consequent to this finding, patients assigned to the lapatinib alone arm of the trial will discontinue lapatinib and discuss treatment options with their study physician.  This study is fully recruited and the remaining three arms of the trial will continue as planned.

Use of lapatinib in an adjuvant setting is not approved anywhere in the world.

About ALTTO

ALTTO (Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization trial; NCT00490139) is a randomised, multi-centre, open-label, phase III study of adjuvant lapatinib, trastuzumab, their sequence and their combination in patients with HER2 positive primary breast cancer. Patients were randomised to receive lapatinib, trastuzumab, trastuzumab followed by lapatinib or the combination of lapatinib and trastuzumab. The primary analysis of the study will test for superiority between the combination arms and trastuzumab alone with respect to disease free survival. 

ALTTO has randomised more than 8,000 patients at nearly 1,500 research sites in 44 countries. Patient enrolment began in June 2007 and completed in 2011.

ALTTO is lead by two prominent academic groups—BIG (Breast International Group) and NCCTG (North Central Cancer Treatment Group) in collaboration with GlaxoSmithKline. Please visit http://www.alttotrials.com for additional information on this trial.

About adjuvant therapy

Adjuvant therapy is additional cancer treatment given after the primary treatment and surgical resection to lower the risk that the cancer will come back. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, targeted therapy, or biological therapy.

About lapatinib (Tykerb/Tyverb)

Lapatinib is approved in 107 countries including the U.S., Europe, Australia, India, Brazil, Russia, Turkey, South Korea and other countries around the world in the metastatic setting.

In Europe, lapatinib, in combination with an aromatase inhibitor (AI), is indicated for the treatment of post-menopausal women with hormone receptor (HR)-positive, HER2 (ErbB2) over-expressing metastatic breast cancer and for whom chemotherapy is currently not intended. In Europe, lapatinib is also approved in combination with capecitabine for the treatment of patients with advanced or metastatic breast cancer whose tumours over-express HER2 and who have received prior therapy including an anthracycline, a taxane, and trastuzumab.

In the United States, lapatinib is indicated in combination with letrozole for the treatment of postmenopausal women with hormone receptor positive metastatic breast cancer that over-expresses the HER2 receptor for whom hormonal therapy is indicated. Lapatinib in combination with an aromatase inhibitor has not been compared to a trastuzumab-containing chemotherapy regimen for the treatment of metastatic breast cancer. Lapatinib is also FDA approved in combination with capecitabine for the treatment of patients with advanced or metastatic breast cancer whose tumours over-express HER2 and who have received prior therapy including an anthracycline, a taxane, and trastuzumab.

US FDA boxed warning and important safety information for Tykerb

Hepatotoxicity has been observed in clinical trials and post marketing experience. The hepatotoxicity may be severe and deaths have been reported.  Causality of the deaths is uncertain.

Patients with known severe hypersensitivity to TYKERB or any of its components should not take TYKERB. Also, patients may experience decreased left ventricular ejection fraction, hepatotoxicity, diarrhea, interstitial lung disease/pneumonitis, QT prolongation, and risk of fetal harm in pregnant women. If TYKERB is to be administered to patients with severe hepatic impairment, dose reduction should be considered.  The most common adverse reactions during therapy with TYKERB plus letrozole compared to letrozole were diarrhea, rash, nausea, and fatigue.  The most common adverse reactions during therapy with TYKERB plus capecitabine versus capecitabine alone were diarrhea, palmar-plantar erythrodysesthesia, nausea, rash, vomiting, and fatigue.

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 further information please visit www.gsk.com

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Under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Factors that may affect GSK's operations are described under 'Risk Factors' in the 'Business Review' in the company's Annual Report on Form 20-F for 2010.