Strong demand for AstraZeneca's new drugs - especially those for cancer - drove a return to sales growth in the third quarter and the drugmaker said it now anticipated years of sustained improvement. 

Product sales in the three months rose 8%, or 9% in constant currencies, which is the benchmark AstraZeneca uses for measuring the return to growth that it has been promising for 2018. 

AstraZeneca has faced a massive loss of patents on older drugs since 2012, wiping out more than half of its sales.

But a batch of 10 new medicines - which grew 85% in the latest quarter - now offer a path to growth. 

"Today marks an important day for the future of AstraZeneca, with the performance in the quarter and year to date showing what we expect will be the start of a period of sustained growth for years to come," its chief executive Pascal Soriot said. 

Promising new medicines include Imfinzi and Tagrisso for lung cancer, Lynparza for ovarian cancer and Fasenra for severe asthma. 

AstraZeneca also has high hopes for diabetes drug Farxiga, which cut heart risks in a major study. The full details of that trial will be unveiled at a medical meeting on November 10. 

China remains a stand-out market, with quarterly sales up 32% in the quarter, as AstraZeneca continued to outperform rivals in the world's second biggest drugs market, where it is turning increasingly to smart tech to drive sales. 

Despite the good news on the product front, however, AstraZeneca is still transitioning to its new growth phase and total revenue and earnings both fell in the quarter, as analysts had expected. 

Overall revenue was down 14% in dollar terms to $5.34 billion and core earnings per share, which exclude some items, declined 37 percent to 71 cents.

This reflected sharply lower income from divestments and investment behind new drug launches. 

Analysts, on average, had forecast earnings of 72 cents on revenue of $5.30 billion, Refinitiv data showed. 

For the full year, AstraZeneca reiterated its forecast of a low single-digit percentage increase in overall product sales in constant currencies and core earnings per share of $3.30 to $3.50.