What: Shareholders of Perrigo PLC (PRGO 2.87%), a drug manufacturer, are having a rough day as the company's stock is down by 11% as of 3:30 p.m. EST. The company reported fourth-quarter earnings that came up short of expectations. 

So what: Revenue came in at $1.42 billion for the quarter, which was up 33% when compared to the year-ago period, and its adjusted earnings per share were $1.80. Both of those numbers came up short of Wall Street's expectations, as the pros were expecting $1.93 in adjusted earnings, and $1.46 billion in revenue.

The huge jump in the company's top line was mostly acquisition related as Perrigo shelled more than 4.0 billion euros last year to acquire the European drugmaker Omega Pharma, and a portfolio of over-the-counter brands from GlaxoSmithKline (GSK 1.22%). The moves led the company to create a new reporting segment that it calls "Branded Consumer Healthcare," but this division appears to be primarily responsible for the earnings miss.

Here's Perrigo's CEO Joseph Papa commenting on the quarter:

Since we closed the Branded Consumer Healthcare acquisition, Euro net sales have improved year over year, due to some exciting new product launches and the acquisition of our new portfolio of leading OTC brands from GSK. Although the segment did not meet our internal expectations, we are taking specific actions to address this performance. 

Now what: Perrigo stock has been taken to the woodshed during the past few months, as it's down more than 36% from its springtime highs. Its stock is still reeling from last year's failed takeover attempt by Mylan N.V. Perrigo's stock initially jumped when news broke that Mylan was interested in buying out the company, but after a long and drawn-out process, the deal ultimately fell through. Perrigo's shares plunged on the news, and its shares have waned ever since.

Looking to 2016, Perrigo's management team is forecasting that its earnings per share will land between $9.50 to $9.80 for the year, which would be strong growth from the $7.59 it recorded in 2015. If the company can prove that it's capable of delivering on its promises, then it's possible that investors could once again warm up to the stock.