Aktis Oncology exceeded its own expectations for its IPO in a good omen for those hoping for a more inviting public market this year.
The company, which has accrued an impressive list of Big Pharma backers in its previous funding rounds, estimated earlier this week that it would sell 11.8 million shares priced between $16 and $18 apiece. But the IPO this morning sees the biotech reach the top end of the price range while bumping up the number of shares to 17.6 million.
The recalibrated figures mean the IPO should bring in gross proceeds of about $318 million—significantly above the net proceeds of $181.7 million the company had predicted Monday.
The proceeds could rise by another $47.6 million if underwriters take up their 30-day offer to buy an additional 2.6 million shares at the same price of $18. The previous expectation was that Aktis would only offer 1.7 million shares to underwriters.
Aktis’ shares are due to start trading on the Nasdaq Friday morning under the ticker “AKTS.”
The $318 million proceeds make the biotech a larger IPO than any of the handful of biotech offerings last year—beating obesity biotech Metsera’s $275 million, LB Pharmaceuticals’ $285 million or MapLight Therapeutics’ $250 million IPOs.
In its filing on Monday, Aktis explained how it had earmarked between $140 million and $150 million of the proceeds to fund the ongoing U.S. phase 1b study of the miniprotein radiopharmaceutical Ac-AKY-1189 for Nectin-4 expressing tumors. Preliminary results from the dose-escalation portion of the study are expected to read out in the first quarter of 2027.
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Aktis has previously pointed out that Pfizer and Astellas’ Padcev, an antibody-drug conjugate that also targets Nectin-4, brought in worldwide sales of $1.9 billion in 2024. Aktis has argued that Padcev has had “limited” impact beyond urothelial cancer due to the need to develop a companion diagnostic.
The biotech is hoping to carve out its own niche for Ac-AKY-1189 by using imaging radioisotopes conjugated to the drug to select patients most likely to benefit from the treatment.
Meanwhile, another $70 million to $80 million of the IPO proceeds is expected to fund the launch a phase 1b study of its second asset, Ac-AKY-2519, for B7-H3 expressing tumors, according to Monday’s filing.
Aktis oversaw 76 full-time employees as of September 2025, who are based across a site in Boston and another in Durham, North Carolina. The company, which ended September with $246.2 million still in the bank, has previously said it expects the IPO proceeds will help keep the company financed until the first half of 2028.
The biotech saw the likes of Bristol Myers Squibb and Merck & Co.’s MRL Ventures Fund join previous backer Eli Lilly for a $175 million series B last year. The pharma attention was based on Aktis’ platform for delivering alpha emitters to cancer cells using miniproteins, an approach that could potentially destroy tumors without causing intolerable harm to healthy tissues.
Aktis’ upsized IPO backs up industry observers’ predictions to Fierce that the IPO window could reopen in 2026—although no other biotechs have yet confirmed they will be following Aktis’ lead this year.
