Merck & Co's fourth-quarter earnings have fallen 7.3%, but new products have helped soften the blow of losing US patent protection on its asthma/allergic rhinitis blockbuster Singulair.

Net income came in at $1.40 billion, while turnover declined 5% to $11.74 billion and pharmaceutical sales fell 6% to $10.1 billion. Singulair (montelukast) sank 67% to $480 million and Merck says it expects a similar decline in Europe following patent expiry in the main markets here in February 2013.

The company's best-selling drug now is the diabetes drug Januvia (sitagliptin) which generated $1.13 billion, up 18%, while Janumet (sitagliptin plus metformin) brought in $452 million, a rise of 17%. Turnover from the HIV drug Isentress (raltegravir) reached $381 million, down 2%, while sales of the cervical cancer vaccine Gardasil soared 61% to $442 million.

Sales of the cholesterol drugs Vytorin (ezetimibe plus simvastatin) and Zetia (ezetimibe) reached $435 million and $676 million, down 8% and up 6% respectively. Revenues from the antihypertensives Cozaar (losartan) and Hyzaar (losartan plus hydrochlorothiazide) fell 26% to $315 million, due to generic competition.

The anti-inflammatory Remicade (infliximab), the Johnson & Johnson drug which Merck sells outside the USA, contributed $549 million, up 8%, while the hepatitis C treatment Victrelis (boceprevir) had sales of $115 million, up 32%, while the herpes vaccine Zostavax shot up from $78 to $225 million.

Chief executive Kenneth Frazier (pictured) said the firm overcame "significant challenges last year…by successfully growing our businesses, expanding geographically and reducing our expenses". He noted that "Merck is rapidly advancing many compounds that are potentially first-in-class or best-in-class", adding that "we will continue to pursue external opportunities that have the potential to deliver value".

Merck expects full-year earnings per share of $2.03-$2.26, compared to $2.16 in 2012. Revenues are scheduled to to be near 2012 levels on a constant currency basis.

Odanacatib filings put back

Merck is on track to file five products for regulatory approval in 2013, but these will not include odanacatib for osteoporosis, which was expected to be filed in the first half of the year. The company has been conducting a blinded extension of a Phase III trial in 8,200 women, which will provide additional safety and efficacy data and use this as part of filings in 2014.

The delay has caused some alarm among analysts but Merck said "it continues to believe that odanacatib will have the potential to address unmet medical needs in patients with osteoporosis".