Updates

** Shares of drug developer Sionna Therapeutics SION.O jump as much as 38.9% in their Nasdaq debut; last up 38.1% at $24.86

** Stock opened for trading at $25 vs $18 IPO price, giving it a market capitalization of $1.06 billion

** SION sold ~10.6 million shares, 20% more than initially offered, at the top end of its marketed range of $16 to $18 apiece to raise $190.6 million

** Founded in 2019 and previously known as Sling Therapeutics, SION is developing drugs to treat cystic fibrosis

** SION is vying for a slice of the cystic fibrosis market that is dominated by drugmaker Vertex Pharmaceuticals VRTX.O

** Vertex booked almost $10 billion in sales in 2023 and has significantly impacted cystic fibrosis treatment

** SION is evaluating its experimental drug candidates SION-719 and SION-451 in early-stage trials in Australia

** Prior to the IPO, SION had raised about $330 million from investors, including RA Capital and TPG's Rise Fund

** Goldman Sachs, TD Cowen, Stifel and Guggenheim Securities were the underwriters

(Reporting by Arasu Kannagi Basil in Bengaluru)

((ArasuKannagi.Basil@thomsonreuters.com))