AstraZeneca has booked a drop in revenues for the fourth quarter but says 2017 could be a 'turning point' for the firm as it comes to the end of its patent-expiry phase and begins its return to growth.

Core earnings for the period came in a $1.21 per share, a rise of 29 percent over the year ago period, or 9 percent when taking currency effects out of the equation. The results beat analyst expectations of $1.14 a share (compiled by Cantor Fitzgerald).

Fourth-quarter revenues hit $5.6 billion, 12 percent down on a year ago (at constant exchange rates), as generic competition continued to hit sales of cholesterol blockbuster Crestor (rosuvastatin), which plummeted 53 percent to $631 million.

Core operating profit for the period was just over $2 billion, up 15 percent on the fourth quarter of 2015.

For the full year, the company booked core earnings of $4.31, down 5 percent on the previous year, revenues of $23 billion, also down 5 percent, and a 7 percent fall in core operating profit to $6.7 billion.

Performance highlights include: 6 percent growth in sales from emerging markets to $5.8 billion, supported by China, up by 10 percent to $2.6 billion; an 11 percent rise in the diabetes franchise, as Farxiga (dapagliflozin) became the AZ' largest-selling diabetes medicine with turnover of $835 million (up 4 percent); a 39 percent leap in sales of cardiovascular therapy Brilinta (ticagrelor) to $839 million; and strong sales of new oncology drugs, which hit $664 million, of which Tagrisso (osimertinib) brought in $423 million from its first year on the market for lung cancer.

On the downside, Japan saw a sales decline of 3 percent to $2.2 billion, reflecting the biennial price reduction in the year, while there was also a 3 percent drop in sales from the firm's respiratory segment to $4.8 billion because of US pricing pressure for Symbicort (fluticasone furoate/umeclidinium/vilantero), which fell 10 percent to just under $3 billion.

Commenting on the results, chief executive Pascal Soriot said they "reflected the ongoing transition of our company".

"Our underlying business is growing as a new AstraZeneca emerges, driven by competitive franchises and Emerging Markets," he said, adding that "2017 has the potential to be a turning point for our company as we near the end of our patent-expiry period and bring new medicines to patients across the globe".

"This year we have the opportunity to launch several life-changing medicines for cancer, respiratory and metabolic diseases. It is an exciting time as we rapidly approach the inflection point for our anticipated return to long-term growth, built on the solid foundations of a science-led pipeline."

But looking forward, AZ's guidance suggests another tough year for the firm, with a low to mid single-digit percentage decline for total revenues and a low to mid teens percentage decline for core earnings per share.