Shares of Protagonist Therapeutics Inc. (NASDAQ:PTGX) climbed 93.9% on Oct. 11 after the FDA removed a full clinical hold on studies of the rusfertide, the company's investigational treatment for the blood disorders polycythemia vera and hereditary hemochromatosis. Triggered by a finding of malignant skin tumors in mice treated with the drug disclosed on Sept. 17, the FDA's three-weeks-ago hold had pushed Protagonist shares down by as much as 72%.