UCB shares fall 8.5% as Bimzelx sales miss despite guidance upgrade

Key Takeaways:

• UCB shares fell 8.5% after raising 2026 earnings guidance
• Bimzelx first-half sales came in slightly below expectations
• Peak sales forecast for Bimzelx raised to 7 billion euros

Belgian biopharmaceutical group UCB raised its 2026 earnings guidance on Thursday, but shares fell more than 8% as investors focused on weaker-than-expected sales of flagship drug Bimzelx and questioned the quality of the upgrade.

"The upgraded guidance appeared to imply second-half EBITDA below market expectations, raising questions about whether part of the first-half outperformance reflected favorable one-off factors rather than a sustained improvement in underlying earnings," analysts covering the stock said.

Adjusted EBITDA is now expected to grow in the mid-teens to low-twenties percentage range at constant exchange rates, up from a previous forecast of high single-digit to mid-teens growth. The company beat first-half revenue forecasts, supported mainly by legacy products, though Bimzelx — its blockbuster anti-inflammatory drug — posted first-half sales that came in slightly below analyst estimates.

The 8.5% selloff in early Brussels trading wiped out gains from the guidance upgrade and pushed UCB shares to their lowest level in weeks. While the company raised Bimzelx's peak sales forecast to 7 billion euros, the miss on first-half sales raised doubts about the drug's near-term trajectory. UCB, which focuses on severe immune-system and neurological diseases, had narrowed its earnings guidance in April to absorb costs linked to a series of acquisitions completed in the first half of 2026.

The selloff signals that investors are pricing in execution risk around Bimzelx's commercial ramp, even as management points to a stronger second half. The next catalyst for UCB shares will be second-half sales data for Bimzelx, which will determine whether the upgraded guidance is achievable without further reliance on legacy product revenue.

This article is for informational purposes only and does not constitute investment advice.