Shares of Halozyme Therapeutics ($HALO) plunged more than 20 percent this morning after the news spread that the FDA wants to see more data on its HyQ Biologics before it can formally decide on its fate. The treatment, which is partnered with Baxter ($BAX), combines Immune Globulin--a solution which contains antibodies--and Recombinant Human Hyaluronidase to treat patients with primary immune deficiencies. The partners said they will design new studies to satisfy the FDA's demands. Report