Fourth-quarter results released by Amgen (AMGN -1.85%) were roughly in line with Wall Street estimates. So, while shares didn't react particularly strongly (and have pretty much tracked the wider Nasdaq index since their release), there were a number of positives in the results that investors should be happy to hear about.

Fourth quarter 2013
Indeed, total revenues in the fourth quarter increased by 13% to just over $5 billion, with product sales growing by 11%. This was despite the end of the Enbrel profit share, making the top-line figures arguably more impressive than at first glance. Furthermore, adjusted earnings per share grew by 30% to $1.82 in the fourth quarter, although a lower tax rate and the inclusion of Onyx Pharmaceuticals (which was acquired in October) help to sweeten this figure somewhat, while increased research and development expenses pinned back earnings growth to an extent.

Product sales growth
Key products that contributed to fourth-quarter sales growth included combined Neulasta and Neupogen sales, which increased by 8%, and Xgeva sales, which increased by 33% in the fourth quarter (versus the fourth quarter of 2012) as a result of higher unit demand. This makes Xgeva the seventh best-selling drug in Amgen's stable.

Interestingly, most of the drugs that experienced significantly higher sales volumes in the quarter were a result of higher demand, as opposed to higher prices. This could be good news for Amgen's medium- to long-term outlook, as it isn't generating higher sales simply from raising prices. Therefore, it could be argued that the current levels of sales growth could be more sustainable than if they had been a result of simply increasing prices.

The pipeline
Looking ahead, Amgen has multiple projected milestones for its late-stage pipeline in 2014. Phase 3 data from Evolocumab, whose lead indication is Dyslipidemia, is expected in Q1 2014, while a U.S. filing for chronic heart-failure drug, Ivabradine, is expected this side of July. In all, there are six different drugs for which phase 3 data is due to be received in 2014, with a phase 2 trial also set to be completed for Blinatumomab, whose lead indication is relapsed/refractory acute lymphoblastic leukaemia, in the first half of the year, too.

An exciting sector?
Amgen's results paint an exciting picture for drug development in 2014, with the company having a relatively strong pipeline -- especially in later-stage assets. As sector peer Alexion (ALXN) reported in its fourth-quarter update, the biotechnology space seems to be gathering momentum in 2014.

Indeed, Alexion is seeking further marketing approvals, particularly for its Soliris drug, which was originally approved in 2007 for the treatment of a life-threatening condition called paroxysmal nocturnal hemoglobinuria. These additional approvals (which include the use of Soliris as an orphan treatment for the prevention of delayed graft function -- granted just last month) caused Alexion to increase its own sales guidance for 2014.

In addition, sector peer Biogen (BIIB 0.42%) has received European Commission aproval for its new multiple sclerosis drug, Tecfidera, and will launch the product in H1 2014. The potential in Europe for the drug seems vast, since it has become the most prescribed pill for the treatment of multiple sclerosis in the U.S. since Biogen gained approval for it in 2013.

Amgen in 2014
Overall, Amgen delivered an impressive set of fourth-quarter results, where it posted double-digit sales and profit growth. This, allied to the relative strength of its product pipeline and multiple regulatory milestones expected this year, means that 2014 could be another exciting year for investors.