Attovia Therapeutics, Inc.
IPO DOSSIER · Nasdaq Global Market: ATTO
Attovia Therapeutics, Inc. (ATTO) IPO
Attovia is developing engineered antibodies against interleukin-31 (IL-31), the immune signal that drives chronic itch in atopic dermatitis (eczema) and in chronic pruritus of unknown origin (CPUO), a persistent itch with no identified cause. It is clinical-stage — no approved product, no revenue — and sold 17,000,000 shares at a fixed $17.00.
WHERE THIS DEAL STANDS
Attovia Therapeutics, Inc. is trading, and Bellipo tracks it through lock-up.
RADAR
Reported, nothing filed
READY
Terms on file, awaiting pricing
PING
Priced, not yet trading
STRIKE
The first trade crosses
ORBIT
Trading, through lock-up
AT A GLANCE
Offer range
$17.00
Priced
Shares offered
17,000,000
Deal size
~$289.0M
At the offer price
First trade
Aug 5
On Nasdaq Global Market
A Bellipo Dossier is built from the filing itself. We aggregate the company's S-1 and its amendments, extract the disclosures that move a deal, and compile them into a single structured brief — the financial statements normalized into comparable lines, the use-of-proceeds split between primary and secondary, the capitalization and ownership table, the underwriting syndicate, insider selling, the auditor and its prior engagements, and the ranked risk factors. Every figure is traced to the source filing rather than the press release. The result is a desk-grade read of what the company disclosed, not what it announced — in plain English, in about five minutes.
Attovia is a clinical-stage biotechnology company working on chronic itch and immune-driven inflammation — beginning with atopic dermatitis (eczema, an itchy inflammatory skin disease) and chronic pruritus of unknown origin (CPUO), a persistent itch with no identified cause. Its lead candidate, ATTO-1310, blocks interleukin-31 (IL-31), the immune signalling protein that tells nerves to itch, and is in a Phase 1/1b trial. Two further candidates are in IND-enabling studies: ATTO-2306, which blocks both interleukin-13 (IL-13, a driver of the skin inflammation behind eczema) and IL-31; and ATTO-1091, which blocks TL1A (a protein that amplifies inflammation in the gut and other tissues), interleukin-23 (IL-23, another inflammatory signal) and integrin alpha-4-beta-7 (the molecule that routes immune cells into the gut lining). The company is based in San Carlos, California, incorporated in Delaware, SIC 2836 (biological products). It has no approved product and no product revenue. Its ATTOBODY biparatopic biologics platform — antibodies engineered to grip two separate sites on a target at once — is in-licensed from Alamar Biosciences, Inc., which is also a greater-than-5% holder. Everything in this dossier is read from the filing.
Industry
Clinical-Stage Biotechnology
Listing
ATTO · Nasdaq Global Market
Website
attovia.com
Lead program as filed
Lead candidate
ATTO-1310
Anti-IL-31 ATTOBODY Fc-fusion protein
Stage
Phase 1/1b
Dosing completed Q1 2026; Phase 1b ongoing
Indications named
CPUO, high-itch AD
Plus cholestatic pruritus and CKD-aP in later trials
Second candidate
ATTO-2306
IL-13 x IL-31 bispecific, IND-enabling
Third candidate
ATTO-1091
TL1A x IL-23 x alpha-4-beta-7 trispecific, IND-enabling
CEO
Tao Fu
Named as CEO and agent for service in the filing
The arc
Dec 2022
Company formed; 800,632 shares issued to Alamar Biosciences under a stock issuance agreement.
Jun 2023
Alamar Platform License Agreement signed; 2,428,646 additional shares issued to Alamar as consideration. Services agreement and sublease with Alamar also signed.
Jun 2023 - Jan 2024
Series A-1 and A-2 preferred sold in two closings for approximately $60.8 million gross. That is those two closings only, not total preferred raised: aggregate gross proceeds from redeemable convertible preferred through March 31, 2026 were $255.8 million.
Q1 2026
ATTO-1310 completed dosing in its Phase 1 trial in healthy volunteers and patients.
Jun 30, 2026
Approximately $115.1 million in cash, cash equivalents and marketable securities (preliminary, unaudited management estimate).
Jul 14, 2026
Form S-1 filed.
Jul 29, 2026
Amendment No. 1 filed with terms: 12,500,000 shares at $15.00-$17.00; 1-for-9.29 reverse stock split reflected.
Aug 4, 2026
Amendment filed: upsized to 17,000,000 shares at an expected fixed price of $17.00, no range on the cover; over-allotment 2,550,000 shares.
Expected Aug 5, 2026
Expected first trade on Nasdaq under ATTO, per exchange calendars. Not a company statement.
- The 21 million adult and 10 million pediatric U.S. atopic dermatitis figures for 2035 are from independent third-party market research studies commissioned by the company. They are company-commissioned estimates, not independent ones.
- The ATTOBODY platform is licensed, not owned. Alamar Biosciences is both the licensor and a greater-than-5% holder.
Form S-1/A, accession 0001193125-26-331510 (filed 2026-07-29).
One candidate dosed in humans, two in IND-enabling studies, a platform licensed from a greater-than-5% holder, and $289.0 million gross asked at a fixed $17.00 with no range on the cover. What the filing settles is the money. What it does not settle is the medicine.
What the filing supports
- ATTO-1310 has human data: greater than 95% IL-31 suppression sustained at least 12 weeks at 4.5 mg/kg and above, which the company cites as supporting quarterly dosing.
- Adverse events as disclosed were predominantly Grade 1 or 2, with no treatment-related serious or severe adverse events and no neutralizing anti-drug antibodies.
- Composition-of-matter coverage on ATTO-1310 is already issued, not pending (US 12,509,510).
- Cash after the offering is approximately $380.2 million on our arithmetic - approximately $115.1 million preliminary at June 30 plus approximately $265.1 million estimated net proceeds - against a $60.6 million net loss in 2025.
- Specialist holders are on the register before the deal - Frazier, venBio, Deep Track, and Goldman-affiliated entities.
What the filing does not settle
- Every efficacy figure is preliminary, exploratory, and from cohorts of 12 to 14 patients in a trial still blinded at the individual level.
- Two of three candidates have never dosed a human, and neither is expected to start Phase 1 before the first half of 2027.
- The platform is in-licensed and the filing itself flags field restrictions, retained rights, and third-party enforcement rights over the licensed portfolio.
- The licensor is also a 12.4% holder, a services vendor and a former sublandlord - the relationship is not arm's length in any simple sense.
- The addressable-market figures are from studies the company commissioned.
The line
No approval decision is pending on this deal and there is no PDUFA date. The next disclosed catalyst is a full Phase 1b readout the company places in Q4 2026 or Q1 2027.
All figures read from Form S-1/A, accession 0001193125-26-331510 (filed 2026-08-04). We do not handicap regulatory outcomes.
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