In the following video, Fool contributor Maxxwell Chatsko tells investors about pipeline developments from Merck (NYSE:MRK). The Food and Drug Administration will review Biologics License Applications, or BLAs, for two investigational allergy tablets in the first half of 2014. Investors awaiting the next big pipeline hit to help replace falling revenue from patent expirations throughout the portfolio should have their ears perked up on the news. 

How do these tablets work in the body? What is their revenue potential? Maxxwell explains just what it means for Merck and investors and answers one important question.