What happened Shares of Aerie Pharmaceuticals (NASDAQ: AERI) jumped more than 14% after the company reported fourth-quarter and full-year 2019 operating results. The commercial-stage pharmaceutical company handily beat expectations for product revenue in the final three months of last year. The business reported fourth-quarter 2019 revenue of $24.7 million, whereas Wall Street analysts were expecting just $19.5 million on average, according to numbers compiled by Yahoo! Finance. That reinvigorated investors who had grown accustomed to disappointing sales figures from the company, although guidance for 2020 supports the excitement. As of 1:54 p.m. EST, the pharma stock had settled to a 10.5% gain. Image source: Getty Images. So what Aerie Pharmaceuticals has served as a reminder to investors that earning marketing approval for an experimental therapy, although difficult, doesn't guarantee success. Companies still have to earn coverage from major insurance programs, avoid manufacturing delays, and persuade doctors to adopt new treatments in crowded markets. Problems in any one of those areas can derail a promising drug's market launch. That's exactly what happened to Aerie Pharmaceuticals. The company developed two novel treatments for glaucoma, now called Rhopressa and Rocklatan. Analysts projected combined peak annual sales of $1 billion. Management projected the duo could grab 40% market share in a crowded glaucoma market. But quarterly revenue totals have routinely disappointed since each drug's market launch. At the end of September, the duo had just 1.5% market share. A strong performance at the end of 2019 injects a little more confidence into demoralized investors. So does rosy full-year 2020 revenue guidance. Aerie Pharmaceuticals reported full-year 2019 product revenue of $69.9 million. It expects to grow that to $100 million to $110 million in 2020. Guidance might be a little conservative considering fourth-quarter 2019 revenue was nearly $25 million, although investors should consider that first-quarter 2020 revenue might slip sequentially due to purchasing trends and inventory planning. Importantly, the company expects to reduce annual cash burn by about $30 million to $40 million in 2020 compared to the prior year. Now what There's still a long way to go for Aerie Pharmaceuticals to live up to its potential, but ending 2019 on a high note suggests the company might be finding its footing. It started 2020 with $309 million in cash, which is enough to fund the ramp-up of Rhopressa and Rocklatan and invest in clinical programs for at least two more years. Now the company only has to execute -- or risk losing its momentum. 10 stocks we like better than Aerie PharmaceuticalsWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Aerie Pharmaceuticals wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of December 1, 2019 Maxx Chatsko has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source