Merck & Co's third-quarter earnings have edged up 2%, helped by one-time tax gains, as new products helped soften the blow of losing US patent protection on its asthma/allergic rhinitis blockbuster Singulair in August.

Net income came in at $1.73 billion, while turnover declined 4% to $11.49 billion and pharmaceutical sales fell 5% to $9.88 billion. Singulair (montelukast) sank 55% to $602 million and Merck says it expects a similar decline in Europe following patent expiry in the main markets here in February 2013.

Taking over as the company's best-selling drug was the diabetes drug Januvia (sitagliptin) which generated $975 million, up 15%, while Janumet (sitagliptin plus metformin) brought in $405 million, a rise of 16%. Turnover from the HIV drug Isentress (raltegravir) reached $399 million, up 16%, while sales of the cervical cancer vaccine Gardasil soared 31% to $581 million.

Sales of the cholesterol drugs Vytorin (ezetimibe plus simvastatin) and Zetia (ezetimibe) reached $423 million and $645 million, down 10% and up 5% respectively. Revenues from the antihypertensives Cozaar (losartan) and Hyzaar (losartan plus hydrochlorothiazide) fell 27% to $295 million, due to generic competition.

The anti-inflammatory Remicade (infliximab), the Johnson & Johnson drug which Merck sells outside the USA, contributed $490 million, down 13%, as a result of the change in marketing rights agreed with J&J for the drug. Merck's new hepatitis C treatment Victrelis (boceprevir) had sales of $149 million, up from $31 million in the like, year-earlier period, while the herpes vaccine Zostavax shot up 87% to $202 million.

Chief executive Kenneth Frazier (pictured) said the firm will still focus on its "four-part strategy of executing on our core business, expanding geographically in high-growth markets, extending our complementary businesses and excelling at managing our costs while investing for growth".  He added that Merck will submit "multiple new products" for marketing approval before the end of 2013, including suvorexant for insomnia, odanacatib for osteoporosis and Tredaptive (extended-release niacin/laropiprant) for atherosclerosis.