GlaxoSmithKline has begun another late-stage trial comparing its new oncology agent Tykerb with Roche/Genentech’s blockbuster Herceptin as a treatment for early breast cancer.

The Phase III study, called Neo-ALTTO, will evaluate and compare the rate at which cancer cells disappear in the breast following treatment with Tykerb (lapatinib) and/or Herceptin (trastuzumab) before surgery in women with early-stage HER2-positive breast cancer. Last year, GSK began a similar trial assessing the two competing drugs when used after surgery.

Tykerb is not yet approved for early use although a fortnight ago, though the European Medicines Agency’s Committee for Medicinal Products for Human Use issued a revised positive opinion for the drug to treat patients with advanced or metastatic breast cancer in combination with Roche's Xeloda (capecitabine). It is already marketed in the USA as Tyverb.

GSK is conducting the study in collaboration with the Breast International Group and the Spanish Breast Cancer Cooperative Group (SOLTI). Target enrollment is 450 patients with 130 clinical trial centres in 26 countries.

Chair of SOLTI, Jose Balsega, said “the evolution seen in breast cancer care has been tremendous in the last few decades," noting that surgery, in the form of a radical mastectomy, was traditionally the first line treatment offered to patients with little or no improvement in overall survival. Now, he claimed, “we have a range of sophisticated targeted treatments that can significantly delay disease progression and increase survival.” Through trials such as Neo-ALTTO, “oncologists may be better able to optimise the use of these agents," Dr Baselga concluded.

GSK noted that one in four women diagnosed with early breast cancer have tumours that are HER2-positive. These women have a higher risk of their cancer returning - either at the location of the original tumour or when the cancer spreads to other organs - even after receiving additional therapies.

Some analysts believe that Tykerb will eventually generate peak annual sales well in excess of $1 billion due to the fact that GSK's drug has the advantage of being orally-active, while Herceptin is dosed by injection.