Attovia Therapeutics Raises $289M in Upsized IPO, Opens 23.5% Above Offer Price on Nasdaq Debut

Attovia Therapeutics, Inc. (Nasdaq: ATTO) priced its initial public offering at $17.00 per share on August 4, 2026 — the top of its targeted range — raising $289.0 million in gross proceeds before underwriting discounts and expenses, according to the company's August 5, 2026 news release on GlobeNewswire.

The offering was upsized to 17,000,000 shares, 45% more than Attovia originally anticipated, per BioPharma Dive. Underwriters — Morgan Stanley, Leerink Partners, Citigroup, and RBC Capital Markets as joint book-running managers, with LifeSci Capital as passive book-running manager — hold a 30-day option to purchase up to an additional 2,550,000 shares at the IPO price, less discounts and commissions.

Shares opened at $21.00 on August 5, 2026 at 12:18 p.m. EDT, a $4.00 gain from the IPO price representing a 23.53% opening move, on volume of 672,648 shares, per IPO Scoop.

Attovia is a clinical-stage biopharmaceutical company developing biotherapeutics for immune-mediated diseases. Founded in 2023 as a spinout of Alamar Biosciences, it had raised approximately $256 million in venture funding as a private company, per the GlobeNewswire release and allsci.com. Its lead pipeline includes ATTO-1310, a half-life extended IL-31-targeting fusion protein for chronic pruritic diseases currently in Phase I — with Phase I dosing in healthy volunteers and patients completed in Q1 2026 — ATTO-2306 for atopic dermatitis, and ATTO-1091 for inflammatory bowel disease. Phase I completion dates for ATTO-2306 and ATTO-1091 are not disclosed in the sources reviewed, and no efficacy readouts for any program appear in the sourced material.

For context on where Attovia sits in the 2026 IPO calendar: per BioPharma Dive, the deal ranks ninth in total proceeds among 2026 biotech IPOs and is the 16th of the year. Twelve 2026 biotech IPOs have secured $250 million or more. The year's largest came from Parabilis Medicines Inc., a rare cancer specialist that raised $770.6 million in June. Biotech IPOs as a class have averaged 55% returns in 2026, against a broader market return of -4.4%, per Briefs.co.

No named CEO or CFO quote was located in primary sources reviewed as of August 7, 2026.

What's next, per the sourced material: underwriters have 30 days from the August 4, 2026 pricing to exercise their option on the additional 2,550,000 shares. That overallotment decision will be the next discrete financing event to watch for in ATTO's public filings.