GlaxoSmithKline has received US approval for its two melanoma pills and a companion diagnostic made by French firm bioMérieux.

Specifically, Tafinlar (dabrafenib) and Mekinist (trametinib) have received marketing approval for patients with advanced or unresectable melanoma, the most dangerous type of skin cancer.

Tafinlar, a BRAF inhibitor, is approved to treat patients with melanoma whose tumours express the BRAF V600E gene mutation.

Mekinist, a MEK inhibitor, is approved to treat patients whose tumours express the BRAF V600E or V600K gene mutations - around half of melanomas arising in the skin have a BRAF gene mutation.

By using the companion diagnostic, called the THxID BRAF test and developed by France’s bioMérieux in conjunction with GSK, doctors can also determine if a patient’s melanoma can be used by these medicines.

“The co-approval of Tafinlar and Mekinist and the second companion diagnostic for BRAF mutation detection demonstrates the commitment of pharmaceutical and diagnostic partners to develop products that detect and target the molecular drivers of cancer,” said Alberto Gutierrez, director of the office of in vitro diagnostic devices at the FDA.

Genetic mutation kits such as THxID BRAF are becoming necessary devices alongside new personalised medicines, with a number of pharma companies pairing up with diagnostic firms – or in the case of Roche, having its own unit – in order to increase the chances of approval of new oncology drugs.

Paolo Paoletti, president of GlaxoSmithKline Oncology, said: “With [the] FDA approvals, GSK can now offer two new single-agent therapies to selected patients who have metastatic melanoma, a devastating disease with very low survival rates and few treatment options.

“GSK Oncology has been focused on progressing research in the most efficient manner possible, and we’re pleased to bring Tafinlar and Mekinist to physicians and their patients in rapid development times.”

The firm said it would be making Tafinlar and Mekinist available for prescription in the USA “no later” than in the early third quarter of 2013.

The two drugs are currently under an accelerated review by the European Medicines Agency, which could make a decision on the medicines by July.

New treatments

Just two years ago melanoma had very few drug options outside of chemotherapy agents such as dacarbazine, and there had not been a new treatment for the disease since the 1970s.

But in 2011 two melanoma medicines: Bristol-Myers Squibb’s cancer vaccine Yervoy and Roche’s Zelboraf for BRAF positive mutations were approved by the FDA, giving late-stage patient with poor prognosis more options.

Both drugs are expected to reach peak annual sales $1.4 billion and $700 million respectively.

Analysts at Cowen and Co. forecast sales reaching about $350 million for each of GSK’s drugs in 2016. Distinctly less than its competition, but they are both second to market after Roche’s treatment, and can only treat around half of all melanoma patients.

Yervoy has the highest potential for peak sales as it can potentially treat all advanced patients as it ‘teaches’ the immune system to fight back against the cancer, instead of targeting a specific mutation.

This week’s approval means there are now four new medicines available for the disease, which The National Cancer Institute estimates will see 76,690 Americans diagnosed with melanoma, with 9,480 expected to die from the disease this year.