The Food and Drug Administration (FDA) has approved two new GlaxoSmithKline drugs that will treat advanced stages of melanoma, Reuters reported.

The two GSC drugs were studied in trials and were found to delay tumor growth, but are not to be used in combination with each other.

Over the past few decades there has been very little progress in finding a treatment for melanoma, the newly approved Tafinlar and Mekinist are the third and fourth new drugs that have been put on the market to treat melanoma over the past year.

The drugs may only be distributed to those who fit specific genetic profiles, as they only target certain gene mutations, which will keep sales on the product low.

The THxID BRAF test was also approved by the FDA, which will help determine which gene mutation is present in the patient so that doctor's know which drug will act as the best possible treatment.

The predicted annual global revenue of Tafinlar is expected to only be at $371 million by 2017, for Mekinist it is projected to be at $425 million, according to forecasts compiled by Thomson Reuters Pharma.

Tafinlar works by inhibiting a protein that's linked to melanoma tumors called MEK.

The approval gives evidence that it has recently become easier for companies to get their drugs into the market. The FDA has approved 13 major drugs this year, by this time in 2011 they had approved 11.

GSK also had success this week with a drug called Arzerra which could treat lymphocytic leukemia. Arzerra was found to be effective in a late-stage study.

Azerra has only been administered in extreme cases so far, but Thomson Reuters Pharma. predicts that it will reach $297 million by 2017.

Deutsche Bank stated that these numbers will most likely rise as competitors begin recognizing the drugs.