An experimental melanoma drug from GlaxoSmithKline managed to shrink secondary tumors in the brains of nine patients with advanced disease, according to results of a small clinical trial.

The development is encouraging because secondary tumors, or metastases, in the brain are a major problem in the deadly form of skin cancer.

Dr. Georgina Long from Melanoma Institute Australia, who led the early-stage Phase I/II study, told the European Society for Medical Oncology (ESMO) congress she was excited by the results.

"Until now, melanoma has been notoriously resistant to drug therapy in general, and responses in highly lethal brain metastases are particularly uncommon," she said.

The latest data come from a subgroup of 10 trial participants with previously untreated brain metastases. All 10 patients experienced control of melanoma brain metastases, and nine of them had reductions in the overall size of their brain metastases, Dr. Long reported.

Melanoma is a particularly difficult cancer to treat and has the greatest capacity of all solid tumors to spread via the blood stream to the brain.

As a result, patients with advanced disease have a very poor prognosis.

Recently, however, hopes for new treatments have started to improve, thanks in large part to good results with two other products in late-stage development — Roche's PLX4032 and Bristol-Myers Squibb's ipilimumab.

Glaxo's new oral drug, known as GSK2118436, is further behind these two in development but it works in a similar way to the Roche product, by targeting a protein called BRAF.

The British-based drugmaker said in July it was pushing ahead with final-stage Phase III trials of the new medicine.