New drug shrinks skin cancer in small trial

An experimental drug shrank skin cancers that had spread, a small-scale drug trial has found.

The drug, called GDC-0449, shrank tumours or improved symptoms in 18 of 33 patients with basal-cell skin cancer that had spread to other organs, researchers said in Thursday's issues of the New England Journal of Medicine and Science Express.

The research was funded by the drug's manufacturer, Genentech, a subsidiary of Roche.

Metastatic basal-cell skin cancer is among the most common but least deadly types of skin cancer.

The compound is designed to block the "hedgehog" signalling pathways that are thought to fuel the growth of some cancers. The pathway was originally named for the oblong, hedgehog-like shape of fly embryos when a key gene in the pathway is disrupted.

Of the 33 subjects, 18 had metastatic disease spread to other organs and 15 had locally advanced disease at the original tumour site. Half of the metastatic cancer patients had their tumours regress by 30 per cent or more.

Resistant case
The Science Express study described one 26-year-old patient with advanced medulloblastoma, an aggressive type of childhood brain cancer, who eventually developed resistance to the drug.

Experiments showed tumours developed a mutation that blocks the action of the drug.

The hedgehog signalling pathway appears to play a role in many cancers, but seems to be especially important for medulloblastoma and basal-cell skin cancer, said study author Dr. Charles Rudin of the Johns Hopkins Kimmel Cancer Center.

The signalling pathways are important during embryo development and become inactivated in adult tissue, except for tumours.

Blocking the pathway could make cancer drugs more selective with fewer side-effects, compared with current chemotherapies, dermatologist Dr. Andrzej Dlugosz and Dr. Moshe Talpaz of the department of internal medicine at the University of Michigan at Ann Arbor, said in a commentary accompanying the NEJM study.

Side-effects included muscle cramping, hair loss, fatigue and low levels of sodium in the blood.

Source : www.cbc.ca