PARIS, June 30, 2026, 01:04 (CEST)
- Abivax ADSs in the U.S. traded at $124.50 as of 7 p.m. ET, jumping 29.49% after hours. The move followed the company’s expanded ABTECT maintenance data release.
- Paris stock ended Tuesday at €83.30, down 1.42%. The late release is set to be priced into the next Euronext session.
- With 79.78 million shares out and each ADS equal to one ordinary share, the after-hours jump adds up to a $2.26 billion boost in equity value.
Abivax S.A. (EPA:ABVX; NASDAQ:ABVX) is set for a lagged Paris opening after its U.S. ADS jumped in after-hours trading. Investors reacted to new clinical data on obefazimod, Abivax’s ulcerative colitis drug. The latest news hits late, but the drop earlier this month wasn’t about whether the drug works. It was about the potential cancer risk and what that could mean for the drug’s label.
Abivax put out the release at 22:05 CEST, after Euronext Paris had already closed for the day at 17:30 and just past the U.S. market close. Euronext Paris trades from 9:00 a.m. to 5:30 p.m. local time and, according to its 2026 holiday calendar, June 30 isn’t a holiday.
| Market line | Last cited price | Move | Read-through |
|---|---|---|---|
| Euronext Paris ordinary share | €83.30 at 17:35 CEST | -1.42% | Market closed ahead of the data |
| Nasdaq ADS, regular session | $96.15 | -1.38% | U.S. session ended before traders saw the news |
| Nasdaq ADS, after hours | $124.50 at 7 p.m. ET | +29.49% | First after-hours trading following fresh safety results |
The ADS traded at $124.50 after hours, leaving it 16.3% under its 52-week high of $148.83. It’s still 11.6% higher than the $111.57 per ADS price Abivax used in May for its royalty-certificate deal, pushing the latest quote above a recent capital structure mark as well as Monday’s session close.
ABTECT Maintenance Part 2 data was the driver for the stock. Abivax said its pooled Phase 2 and Phase 3 ulcerative colitis safety set includes 1,704 patient-years of exposure. Malignancy rates were in line with what’s expected for ulcerative colitis.
| ABTECT item | New data point | Comparison |
|---|---|---|
| Induction non-responders, 50 mg | Clinical remission seen in 37.2%; endoscopic remission at 34.5% | With 25 mg: 23.5% clinical, 22.2% endoscopic |
| Relapsers after placebo re-randomization | Clinical remission rate 45.0%, response 69.7% | Escalating from 25 mg to 50 mg showed 45.5% remission, 66.7% response |
| Malignancies excluding non-melanoma skin cancer, integrated UC program | Rate was 0.35 events per 100 patient-years for all-active arm | UC background expected at 0.30-0.70 |
| Non-melanoma skin cancer, integrated UC program | Recorded 0.59 events per 100 patient-years, all-active group | CU background rates: 0.70-1.40 |
CEO Marc de Garidel said the broader safety data “strengthens our confidence” in obefazimod’s long-term outlook. Remo Pannacione, professor of medicine and IBD Clinic director at the University of Calgary, said the cancer and skin-cancer rates seen so far matched expected background rates. Abivax
Keith Fournier, Abivax’s head of regulatory affairs, told Reuters that four independent former senior FDA leaders said it’s “highly unlikely” the agency will give its strictest boxed warning. That’s what matters for the stock—investors can shrug off efficacy if they think the label will restrict use. Reuters
The June 1 data showed strong remission numbers: 50.8% on 25 mg and 51.3% for 50 mg by week 44, while placebo was just 10.4%. Still, three cancer-linked cases in the 50 mg group weighed on shares. Jefferies called those cases a break for their investment thesis. Yale Jen at Laidlaw & Company said the market reaction was an “overreaction” and called the top-line data a “homerun.” Abivax
Balance sheet figures are in focus. Abivax reported €491.6 million in cash, cash equivalents and short-term investments as of March 31. The company said this should fund operations into the fourth quarter of 2027. R&D costs for the first quarter stood at €49.5 million, with 94.5% spent on obefazimod.
Abivax moved to clean up its balance sheet in May, paying $90 million to buy back all outstanding royalty certificates. The payment came half in cash and half in 403,347 ADSs, a roughly 0.5% dilution. CFO Didier Blondel said the balance sheet remains a “core priority.” SEC
Abivax chief medical officer Fabio Cataldi said after reporting June 1 maintenance data that the company is still “on track” for an NDA filing. Next up is the half-year report on Sept. 21, followed by a planned U.S. filing for obefazimod in the fourth quarter. Phase 2b topline Crohn’s disease data are due in mid-2027. Abivax
