UCB Soars to Record as Rival MoonLake Crashes on Trial Data

(Bloomberg) — Shares in Belgium’s UCB SA soared to a record, while rival MoonLake Immunotherapeutics is set to lose most of its value, after the latter announced late-stage trial data for an experimental skin disease drug that analysts said failed to demonstrate superiority to one of UCB’s most important medicines.

UCB shares surged as much as 20%, adding more than €7 billion ($8.2 billion) in market value. MoonLake plunged as much as 87% in US premarket trading, with the stock set to erase most of its $4 billion capitalization.

The key data point for MoonLake’s sonelokimab in patients with moderate to severe hidradenitis suppurativa — measured by a reduction in skin abscesses and inflammation — showed a combined efficacy of 14% on a placebo adjusted basis across two studies, according to Morgan Stanley analysts. UCB’s Bimzelx treatment showed an 18% placebo adjusted benefit in previously announced trial results.

The profile for sonelokimab is “unambiguously inferior” to Bimzelx in hidradenitis suppurativa, JPMorgan Chase & Co. analyst Richard Vosser wrote in a note.

UCB shares have soared roughly 190% since late 2023, when Bimzelx was approved in the US to treat psoriasis. Bimzelx has also received approval to treat hidradenitis suppurativa, or HS, a debilitating disease that causes painful skin abscesses and scarring.

HS is a crucial growth area for UCB, with the disease making up 21% of Bimzelx’s global net sales in the first half of 2025. The HS market could grow to $15 billion by 2035, from $2 billion currently, because there are a large number of untreated patients with the disease, according to an April presentation by MoonLake.

“We expect the MoonLake update to be a big clearing event for investors,” TD Cowen analyst Stacy Ku said in a note. UCB’s market value now exceeds €44 billion.

Shares in Financiere de Tubize SA, a listed investment vehicle for the family of UCB founder Emmanuel Janssen, also got a big boost, jumping as much as 17% to a record high.

–With assistance from Subrat Patnaik.

(Adds market value swings in second paragraph, JPMorgan comment in fourth.)

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