There's been plenty of good news for GlaxoSmithKline over the last few days with the UK drug giant celebrating a positive opinion on marketing approval for its seizure drug Trobalt in Europe and confirming the start of late-stage clinical trials of two targeted skin cancer therapies.

GSK and development partner Valeant announced Friday that the European Medicines Agency’s Committee for Medicinal Products for Human Use has recommended a green light for Trobalt (retigabine) as an add-on treatment for partial onset seizures in adults with epilepsy, thereby overcoming the penultimate hurdle on the path to market approval.

Around one-third of patients with epilepsy experience seizures despite treatment, highlighting the urgent need for new effective treatment options to manage the condition and the potential for Trobalt to take advantage of this unmet need, and peak sales forecasts for the drug - the first potassium channel opener in development for epilepsy - range from $200-$800 million.

Trobalt, which is known as Potiga (ezogabine) in the US, received a preliminary approval from Swissmedic, the Swiss Agency for Therapeutic Products, in December last year, but the drug's application in the US has temporarily stalled after the Food and Drug Administration issued a complete response letter for the drug on non-clinical grounds.

Melanoma drugs in Ph III

Meanwhile, GSK also said that two of its investigational drugs have started Phase III clinical trials in advanced or metastatic melanoma patients with a BRAF V600 mutation.

The two studies will look at the efficacy and safety of GSK2118436 and GSK1120212 to determine whether they are capable of slowing or stopping the progression of skin cancer in patients with this particular defect, which affects around 50% to 60% of melanoma patients, the drugmaker said.

BRF113683 is a randomised, open-label study designed to compare the BRAF inhibitor GSK’436 to the chemotherpy dacarbazine in previously untreated patients, while the METRIC trial compares the MEK inhibitor GSK’212 to chemotherapy (dacarbazine or paclitaxel) in advanced or metastatic melanoma patients.

Paolo Paoletti, President of GSK Oncology, noted that the investigational agents are also being studied alone and in combination with other therapies in various other difficult to treat cancers such as pancreatic cancer and relapsed leukaemias.