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%.
Shares of Protagonist Therapeutics Inc. (NASDAQ:PTGX) fell 62% to $17.53 on Sept. 17 after it reported finding malignant skin tumors in a mouse model test of its most advanced candidate, rusfertide for blood disorders. After the company notified the FDA, the regulator put the program on a clinical hold, leading dosing of patients in all ongoing trials of rusfertide to be halted for now. The development could impact Protagonist's ability to start phase III testing of the candidate in polycythemia vera (PV) early in 2022, as well as efforts to expand its development to a third indication beyond PV and hereditary hemochromatosis (HH) by the end of this year, as it has planned.
“All along our guidance has been that, look, we are doing multiple open-label studies with the intent of picking a winner,” said Protagonist Therapeutics Inc. CEO Dinesh Patel during a conference call with investors. “Today, we have picked a winner by a huge margin” in the shape of PTG-300, an injectable hepcidin mimetic for the rare blood cancer polycythemia vera (PV).
Protagonist Therapeutics Inc. stock (NASDAQ:PTGX) nosedived 47% on Tuesday after the company released preliminary results from its phase II open-label study of PTG-300, an injectable hepcidin mimetic to treat patients with transfusion-dependent beta-thalassemia.
