GlaxoSmithKline has announced the start of the first late-stage trial of its investigational cancer drug Tykerb in squamous cell carcinoma of the head and neck.

The global, Phase III study will enroll 680 high-risk patients with locally advanced head and neck cancer (stages II, III and IVa) that have undergone surgery and patients will receive, within four to seven weeks after surgery, either 1,500mg of Tykerb (lapatinib) or placebo tablets once-daily with radiotherapy and cisplatin for seven weeks. After that, patients will continue with either lapatinib or placebo for a year and the principal objective will be to investigate the length of time without disease symptoms, and overall survival with other clinical factors will also be measured, GSK noted.

The company noted that head and neck is the sixth most common cancer worldwide, with 600,000 patients diagnosed annually, including 100,800 in Europe. 40,000 people die of the disease every year.

Prof Jean Bourhis of the Institute Gustave Roussy in France and principal investigator said the trial “represents another exciting step towards understanding the role of lapatinib in other tumour types beyond breast cancer." He added that "there is a significant group of patients who are at high-risk of disease recurrence following surgery, and they need new treatments that can be combined with standard chemoradiation therapy."

The announcement coincided with the International Meeting on Innovative Approaches in Head & Neck Oncology in Barcelona, Spain, where GSK presented results from a Phase I dose-escalation study of lapatinib, where doses ranged from 500mg to 1,500mg) plus chemoradiation in 31 head and neck cancer patients. The data showed that 1,500 mg of lapatinib taken once-daily with chemotherapy and radiotherapy was the optimal dose for this combination, so this dose was selected for the Phase III study.

Additionally, 89% of patients had a tumour response to this combination treatment and the most common side effects in the Phase I study were mouth ulcers (87%), radiation skin injury (65%), nausea (61%), swallowing difficulties (52%) and vomiting (52%).

Tykerb, in combination with capecitabine, has been submitted for marketing approval in the USA, European Union and Switzerland for the treatment of advanced or metastatic HER2-positive breast cancer in women who have progressed despite prior therapy, including trastuzumab. Registration dossiers have also been filed in Australia, Canada and New Zealand.

Tykerb could be a blockbuster simply from the breast cancer indication alone but with studies going on in brain and kidney as well as head and neck cancers, analysts have very high hopes for the drug.