David Phillips

AbbVie is spending more than 16% of annual sales to develop new drugs that will lesson the drug maker's dependence on the rheumatoid arthritis drug Humira. Fortunately, the Chicago-based drug manufacturer has a stable of off-patent, legacy drugs that contribute sizable sales to this R&D effort.

A published survey of rheumatologists suggests that growth in key European markets for AbbVie’s (NYSE: ABBV) flagship drug Humira could stall as biosimilar options become more prevalent. Absent longer-term safety data on these follow-on drugs, Humira should continue to shine.

Pfizer (NYSE: PFE) remains committed to maintaining a leadership position in global pain-treatment markets, despite the upcoming loss of market exclusivity for Celebrex. Foolish investors should remain wary of management promises.

The share price of Zogenix has soared more than 260% during the past year, driven by investor optimism for new opioid painkiller Zyhydro ER. Will the drug be a commercial success?