FDA approves Impax generic of Merck's cholesterol drug Vytorin

April 26 (Reuters) - The U.S. Food and Drug Administration on Wednesday approved Impax Laboratories Inc's generic version of Merck & Co's cholesterol-reducing drug Vytorin, the first cheap competitor for a drug that in 2016 generated more than $1 billion in sales.

Vytorin is a combination product that includes the drugs ezetimibe and simvastatin, sold under the brand names Zocor and Zetia. Zocor lost patent protection in 2006. Zetia lost patent protection on Tuesday. Zetia generated 2016 sales of $2.6 billion.

In general, revenue from branded products falls by 90 percent once multiple generics hit the market. Vytorin currently costs about $300 for a supply of 30 tablets.

Merck faces generic competition this year not only to Vytorin and Zetia, but also to its antibiotic Cubicin and its Nasonex nasal spray in the United States and for its arthritis drug Remicade in Europe.

The company is betting it will ultimately offset those losses with other drugs, including its cancer drug Keytruda, which is approved for certain patients with non-small cell lung cancer and melanoma and is being tested in a range of other cancers as well.

Merck in February issued a 2017 profit forecast that was in line with Wall Street expectations. (Reporting by Toni Clarke in Washington; Editing by Savio D'Souza)