Gilead Sciences Inc. GILD is scheduled to report first-quarter 2016 results on Apr 28, after the market closes. Last quarter, the company had comfortably surpassed expectations with a positive earnings surprise of 12.37%. Will this biotech major be able to beat estimates this time around as well? Let’s see how things have shaped up for this quarter.Factors Driving Q1 ResultsGilead’s blockbuster hepatitis C virus (HCV) drug Harvoni should continue to contribute significantly to the top line in the first quarter of 2016 as well. Moreover, Harvoni sales should benefit from label expansion that came last November. However, sales of another HCV drug at Gilead, Sovaldi, has been witnessing a slowdown (declining 10.7% year over year in the fourth quarter of 2015) due to the availability of newer HCV therapies including Harvoni and AbbVie Inc.’s ABBV Viekira Pak.On the fourth-quarter call, Gilead had said that its HCV franchise should benefit from launches of HCV products in international markets as well as continued launches across Europe in 2016. While the company expects the number of patients in the U.S. to be similar to 2015 levels, it should grow in Europe. Notably, the company expects to see more patients being treated with shorter durations. Investor focus will primarily remain on the impact of the recently launched, lower priced HCV drug, Zepatier.Other anti-viral products, such as, Complera/Eviplera should aid revenues whereas Atripla should continue declining. Focus would also be on Genvoya, the company’s first tenofovir alafenamide (TAF)-based regimen for the treatment of HIV-1 infection. The drug has been off to an encouraging start since its launch in Nov 2015. The company noted on the fourth-quarter call that 80% of Genvoya sales came from switches from another HIV-1 drug, Stribild, belonging to Gilead.Meanhwile, two other TAF-based regimens for the treatment of HIV – Odefsey and Descovy – recently gained approval.For 2016, Gilead expects net product sales in the range of $30–$31 billion. On the first quarter call, investors could see an update on the guidance based on the company’s performance. Meanwhile, the company is actively pursuing share repurchases as well as partnerships/acquisitions to expand its product portfolio beyond antivirals into other therapeutic areas. This should be another area of focus.Surprise HistoryGilead’s track record has been impressive with the company beating earnings estimates consistently. In fact, Gilead has posted a positive earnings surprise in each of the trailing four quarters, with an average beat of 7.79%.Why a Likely Positive Surprise? For the first quarter of 2016, our proven model also shows that Gilead is likely to beat earnings estimates because it has the right combination of two key ingredients. Positive Zacks ESP: Earnings ESP, which represents the difference between the Most Accurate estimate and the Zacks Consensus Estimate, is +1.65%. This is a meaningful and leading indicator of a likely positive earnings surprise for the shares. Zacks Rank #1 (Strong Buy): Note that stocks with Zacks Ranks of #1, #2 (Buy) and #3 (Hold) have a significantly higher chance of beating earnings. However, we caution against stocks with a Zacks Rank #4 or 5 (Sell-rated stocks) going into the earnings announcement, especially when the company is seeing negative estimate revisions. The combination of Gilead’s Zacks Rank #1 and +1.65% ESP makes us makes us reasonably confident of an earnings beat this season. Other Stocks That Warrant a Look Gilead is not the only company looking up this earnings season. Here are a couple of other health care stocks that you may want to consider as our model shows that they too have the right combination of elements to post an earnings beat this quarter. Innoviva, Inc. INVA has an Earnings ESP of +77.78% and a Zacks Rank #2. It is scheduled to report first-quarter results on Apr 28. Amgen Inc. AMGN has an Earnings ESP of +3.52% and a Zacks Rank #3. It is scheduled to report first-quarter results on Apr 28. Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report GILEAD SCIENCES (GILD): Free Stock Analysis Report AMGEN INC (AMGN): Free Stock Analysis Report ABBVIE INC (ABBV): Free Stock Analysis Report INNOVIVA INC (INVA): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research