As the countdown to 2013 continues, it's important for investors to look back and assess the year. Before we dive into Merck's (NYSE: MRK) most notable successes and failures of 2012, however, let's take a quick look at the company's performance last quarter.

Q3 Results

Merck announced its third quarter earnings near the end of October, and considering Singulair's patent expiration, it was no surprise that revenue took a hit. Singulair's year-over-year sales sales plummeted by a whopping 55% — but the company's overall sales only decreased by 4%.

How was Merck able to mute the effects of Singulair's drastic slump?

One driving force was growth from the company's diabetes drugs Januvia and Janumet, which posted year-over-year sales increases of 15% and 16%, respectively. Last quarter also had strong showings from the company's HPV vaccine Gardasil and HIV drug Isentress, sales of which grew by 31% and 16%, respectively.

MRK Pharmaceutical Revenue, Q3 2012

A few cost-cutting measures, a lower tax rate compared to the same quarter last year, and a healthy 7% boost from the consumer care division also helped to offset the losses faced by Singulair's patent expiration. All told, it was a solid quarter for the big pharma stalwart.

With the first quarter after Singulair's patent loss now under it's belt, investors are turning their attention to Merck's pipeline. In the next update, we'll look at some of Merck's recent clinical trial victories and failures.

Fool contributor Brian Orelli has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.