GlaxoSmithKline has filed for approval of two melanoma treatments in the US and EU, raising hopes of yet more treatment options in this hard-to-treat form of skin cancer.
The pharma company submitted BRAF inhibitor dabrafenib in both the US and EU as a treatment for adults with unresectable or metastatic melanoma who carry a mutation in the BRAF V600 gene, the same target as Daiichi Sankyo/Roche’s Zelboraf (vemurafenib) which was approved in the US last year and in Europe in February.
Meanwhile, the UK-headquartered pharma major has also filed for approval of its MEK inhibitor trametinib in BRAF V600-positive patients in the US, with an EU submission scheduled for the next few months.
Both MEK and BRAF are key targets in the oncogenic pathway in melanoma, and having drugs available to treat both targets is expected to reduce the chances of treatment failure because of tumour resistance.
The mutated BRAF gene is involved in around 50 per cent of malignant melanomas, according to the Institute of Cancer Research (ICR).
While the marketing submissions are for each drug as single-agent therapies in melanoma, GSK is carrying out a phase III trial of them in combination, with the help of a genetic test for BRAF V600 mutations developed at diagnostics specialist bioMerieux.
The prospects for patients with melanoma have been transformed of late with the approval of new drugs, including Zelboraf and Bristol-Myers Squibb’s antibody-based CTLA-4 inhibitor Yervoy (ipilimumab), an immunotherapy which debuted in the US in the first quarter of 2011.
Both Zelboraf and Yervoy have got off to strong starts in the marketplace – pulling in sales of 92m Swiss francs ($95m) and $316m respectively in the first half of this year – and GSK’s candidates are also expected to be big sellers if approved.
Yervoy is tipped to become the go-to drug in BRAF-negative melanoma with peak sales of $2bn or more, while Zelboraf will benefit from its first-to-market status in the BRAF inhibitor class and pull in around $1.5bn, according to analysts.
GSK’s double-whammy approach will also stand it in good stead, however, with combined peak sales of $2.4bn predicted by 2020.
The pharma major is currently carrying out a comparative study of its combination therapy against Zelboraf with results due in 2013.