Optimism on Wall Street proved wise and shares of Mirum Pharmaceuticals Inc. (NASDAQ:MIRM) rose accordingly to close June 17 at $33, up $7.08, or 27.3%, as the firm disclosed interim results from two phase IIb studies evaluating volixibat, an oral ileal bile acid transporter (IBAT) inhibitor, in patients with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). The drug proved its mettle in both liver biliary tract-stenosing indications, with no new safety signals turning up, Foster City, Calif.-based Mirum said.