What happened Gilead Sciences (NASDAQ: GILD), the undisputed king of anti-viral medications, was unable to shrug off the moody market last year. In fact, the biotech's stock traded pretty much in lockstep with the industry as a whole in 2018 -- leading to a disappointing 12.7% decline in its share price over the course of the year, according to data from S&P Global Market Intelligence. Image source: Getty Images. So what Gilead's inability to swim against the current last year can be directly attributed to two key events. First off, Gilead's hepatitis C franchise continued to sink at an alarming rate in 2018 due to the emergence of new competitive threats such as AbbVie's Mavyret, as well as a rapidly shrinking marketplace. Gilead is thus expected to post a whopping 16.6% decline in revenue for the year when it releases its fourth-quarter and full year results early next month. Secondly, CEO John Milligan announced that he would be stepping down last July, but the company didn't name a replacement until early December. This nearly five-month-long leadership transition seemingly put the brakes on the biotech's business development plans for the better part of 2018. Now what Fortunately, Gilead's days of wandering in the abyss appear to be at an end. As proof, the biotech named Roche executive Daniel O'Day as the next CEO, and it signed a sizable immuno-oncology partnership with Agenus last month. Taken together, these two bold moves clearly show that Gilead has big plans for its nascent oncology franchise going forward. And that's arguably a rather smart decision. Cancer therapies, after all, tend to have appreciably longer shelf lives from a commercial standpoint than anti-viral drugs. 10 stocks we like better than Gilead SciencesWhen 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 quadrupled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and Gilead Sciences wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of November 14, 2018George Budwell owns shares of AbbVie. The Motley Fool owns shares of and recommends Gilead Sciences. The Motley Fool has a disclosure policy.