AstraZeneca (AZN 0.32%) announced its fourth-quarter and 2019 full-year financial results on Friday morning. While the company reported impressive sales growth in a number of its top-selling drugs, investors are worried that the novel coronavirus outbreak could significantly eat away at the company's 2020 sales.

Revenue came in at $6.7 billion, a 3.8% increase from last year. Product sales accounted for the majority of this figure, around $6.25 billion, which is up a healthy 8.4% from Q4 2018. The remaining $414 million came from collaboration revenue, which has shrunk by 36.2%. In terms of specific products, AstraZeneca's non-small cell lung cancer drug Tagrisso brought in $884 million in revenue, a 49% increase from last year. Another top performer for the company, a cancer drug called Imfinzi, is up 62% from Q4 2018 and brought in $424 million.

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Despite strong growth in a number of the company's drugs, the bottom line remains less than impressive. Profit after tax came in at only $277 million for the quarter, which is a 72% decline from last year.

What's in store for the future?

The pharmaceutical giant also warned that 2020 revenues could be significantly impacted due to the coronavirus epidemic. Chinese sales have been a major revenue driver for AstraZeneca, which grew 35% in 2019 alone. Considering China is the AstraZeneca's fastest-growing market, the company's growth prospects for 2020 could be significantly hampered by further outbreaks of the coronavirus.

The company's 2020 guidance expects high-single-digit to low-double-digit percentage increases in revenue assuming that the coronavirus doesn't last more than a few months.