NEW YORK (TheStreet) -- Perrigo  (PRGO - Get Report) stock is plunging by 12.85% to $105.70 in pre-market trading on Monday, as the company will not fight the departure of CEO Joseph Papa as he leaves for rival Valeant Pharmaceuticals (VRX).

Perrigo has appointed President John Hendrickson to succeed Papa, effective immediately following Papa's departure. Hendrickson has been with Perrigo for 27 years and has led several of its operations including its U.S. consumer healthcare business. 

Papa will join Valeant in early May, according to a statement by Valeant.

Additionally, Perrigo expects to report 2016 first quarter adjusted earnings between $1.71 and $1.77 per share on revenue between $1.33 billion and $1.35 billion. Analysts are looking for earnings of $1.89 per share on revenue of $1.4 billion for the most recent quarter.

For the full year, Perrigo expects to report adjusted earnings between $8.20 and $8.60 per share. The guidance update reflects lower pricing expectations for its Rx segment due to "industry and competitive pressures in the sector," as well as anticipated weakness in the BCH segment and reduced expectations for consolidated new product launches. 

Perrigo will report 2016 first quarter earnings before the market open on May 12.

Separately, TheStreet Ratings team rates the stock as a "hold" with a ratings score of C.

Perrigo's strengths such as its robust revenue growth, expanding profit margins and largely solid financial position with reasonable debt levels by most measures are countered by weaknesses including deteriorating net income, disappointing return on equity and weak operating cash flow.

You can view the full analysis from the report here: PRGO

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this article's author.