Prothena Corporation plc PRTA is expected to report first-quarter 2016 results on May 3.Prothena’s track record has been has mixed so far. Over the last four trailing quarters, the company’s earnings missed estimates in the two quarters and beating the same in the other two, with an average negative earnings surprise of 0.89%.Let us see how things are shaping up for this announcement.Factors at PlayWith no approved product in its portfolio yet, investor focus should remain on pipeline updates by the company. Currently, its pipeline includes three lead immunotherapy programs – NEOD001 for the potential treatment of AL amyloidosis, PRX003 for the treatment of psoriasis, and PRX002 for the treatment of Parkinson’s disease and other related synucleinopathies.NEOD001 is currently being evaluated in a phase III study in newly diagnosed treatment- naïve patients with AL amyloidosis and cardiac dysfunction. Moreover, Prothena plans to initiate a phase IIb study on the candidate in previously-treated patients with AL amyloidosis and persistent cardiac dysfunction in the second quarter of 2016. Meanwhile, both PRX002 and PRX003 are being evaluated in phase I studies.The company’s top line mainly comprises collaboration revenues under its license agreement with Roche Holding AG RHHBY for PRX002.Like any other development-stage biotechnology company, Prothena is likely to see an increase in research and development expenses due to higher spending on pipeline development.What Our Model IndicatesOur proven model does not conclusively show that Prothena is likely to beat estimates this quarter. That is because a stock needs to have both a positive Earnings ESP and a Zacks Rank #1 (Strong Buy), #2 (Buy) or #3 (Hold) for this to happen. Unfortunately, that is not the case here, as you will see below.Zacks ESP: The Earnings ESP for Prothena is 0.00%, as both the Most Accurate Estimate and the Zacks Consensus Estimate stand at a loss of 70 cents.Zacks Rank: Prothena currently carries a Zacks Rank #4 (Sell). As it is, 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.Stocks to ConsiderHere are a couple of health care stocks you may want to consider, as our model shows that they have the right combination of elements to post an earnings beat this quarter.The Earnings ESP for Zoetis Inc. ZTS is +2.44% and it carries a Zacks Rank #3. The company is scheduled to release results on May 4.The Earnings ESP for Agios Pharmaceuticals, Inc. AGIO is +30.44% and it carries a Zacks Rank #3. The company is expected to release first-quarter results on May 5.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 ROCHE HLDG LTD (RHHBY): Free Stock Analysis Report AGIOS PHARMACT (AGIO): Free Stock Analysis Report PROTHENA CP PLC (PRTA): Free Stock Analysis Report ZOETIS INC (ZTS): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research