Corbus Pharmaceuticals Holdings Inc $CRBP nosedived after TheStreet�s Adam Feuerstein said that the stock is �headed for a big fall�, citing an unidentified healthcare fund manager who earlier shorted CytTx, Mast Therapeutics, Immunomedics and others. The analyst added that Resunab, the sold drug in the research pipeline, doesn�t work. The drug-maker is slated to provide the top-line results from mid-stage study of Resunab later this quarter.