It’s a supersized Tuesday: Attovia Therapeutics (ATTO Proposed), a Phase 1 biotech developing drugs to treat chronic pruritis (itching) and IBD, upsized its IPO to $289 million – up from $200 million – in an S-1/A filing early today (Tuesday, Aug. 4, 2026). The California biotech increased the number of shares to 17 million – up from 12.5 million shares originally – and set the IPO price at $17.00 – the top of its $15.00-to-$17.00 range – to raise $289 million. That’s an upsizing of 44.5 percent.
Under the new pricing terms, Attovia Therapeutics would have a market cap of $731.49 million.
Morgan Stanley, Leerink Partners, Citigroup, RBC Capital Markets and LifeSci Capital are the joint book-runners.
Attovia, based in San Carlos, California, plans to start Phase 1 clinical trials next year for its three drug candidates, the prospectus said.
Alamar Biosciences (ALMR), which went public in mid-April, is one of Attovia’s founding shareholders. Goldman Sachs Alternatives is also a principal shareholder.
Financial Snapshot: Net loss of $64.13 million on collaboration revenue of $1.35 million for the 12 months that ended on March 31,2026