Positive results halt trial of new Herceptin rival
pharmafile | May 3, 2006 | News story | Research and Development |Â Â Â
Better than expected results for a new drug for advanced breast cancer have led to trials being halted, in order to allow more women to benefit from the treatment.
GlaxoSmithKline's Tycerb (lapatinib) was being used to treat advanced breast cancer in women in combination with capacitabine (Roche's Xeloda) in phase III trials comparing it with capacitabine alone.
Results were so positive for the women taking the new combination that an independent monitoring committee said enrolment in the trial should end, with all women on the trial given the choice of receiving the dual therapy.
Like the much-publicised Herceptin, GSK's new drug targets the sub-group of women with breast cancer who have an aggressive form of the disease, known as HER2 or ErbB2 positive.
Herceptin works by blocking the effect of the ErbB2 gene, which is associated with cancer that grows faster and spreads to other organs more quickly.
By blocking the stimulation of these genes, Herceptin can slow or halt the progress of the disease and ultimately save lives.
But Tycerb could have significant benefits over Herceptin. Firstly, the new drug not only targets the ErbB2 receptor but also the similar ErbB1 receptor, which is also associated with accelerated cancer growth. By blocking the stimulation of both genes, GSK hopes its drug could be even more effective than Herceptin.
Secondly, lapatanib is a small molecule drug taken as a pill, making it easier to manufacture and more convenient for patients compared to Herceptin, which must be administered via intravenous infusion.
Paulo Paoletti, head of GSK's oncology development centre commented: "We are extremely encouraged by these data which suggest that Tycerb may offer significant benefit as an oral medication in combination with chemotherapy for patients with advanced or metastatic ErbB2 positive breast cancer, and whose disease has progressed on previous treatment regimens, including Herceptin.
"On the basis of this and other data we now plan to file in the US and Europe during the second half of 2006."
By the time women are first diagnosed with breast cancer, between 10-20% are already in the advanced stages of the disease, with either locally advanced tumours or a metastatic tumour spreading the cancer to other organs.
Currently the median survival time for these women is just two years, and GSK hopes Tycerb will prove to be an advance in treating these women.
The company has not released extensive details of the trial results, but has confirmed that the drug significantly exceeded its primary endpoint of a 50% increase in the time to disease progression (TTP).
GSK says it is using advanced technologies, including pharmacogenetics to determine which patients will respond the most to the new drug.
