Boehringer Ingleheim, LEO Pharma Announce Partnership to Advance Spesolimab in GPP and Beyond

Boehringer Ingelheim and LEO Pharma announced today that both companies have entered into a partnership and exclusive global license and transfer agreement for advancing the development and commercialization of spesolimab (Spevigo).¹

The agreement aims to accelerate and expand global access to spesolimab for adult and pediatric patients with generalized pustular psoriasis (GPP).

Under the terms of the agreement, Boehringer Ingelheim will transfer global rights to LEO Pharma in exchange for a €90 million upfront payment, with additional milestone payments and royalties. The transaction is expected to close in the second half of 2025, pending regulatory clearance.

IL-36 as a Driver in GPP

Spesolimab, a humanized monoclonal antibody, binds to the IL-36 receptor, blocking downstream inflammatory signaling. In the pathogensis of GPP, IL-36 dysregulation drives massive neutrophilic infiltration, keratinocyte activation, and systemic inflammation.²

The US FDA approved spesolimab for GPP in 2022 for adults and pediatric patients aged 12 and above weighing ≥40 kg, as the first treatment specifically indicated for GPP flares.³ The approval was based on positive data stemming from the pivotal Effisayil-1 trial, a randomized, double-blind, placebo-controlled study demonstrating rapid pustular and systemic symptom clearance following a single intravenous dose.⁴

Spesolimab is now approved in over 40 countries, including the US, Japan, China, and the European Union, for acute GPP flares. It has also received expanded indications in some jurisdictions for broader use in GPP management and is currently under investigation for other IL-36-mediated dermatoses.

Clinical Implications and Expert Insights

With this agreement, LEO Pharma will assume full responsibility for future development, medical affairs, market access, and global distribution of spesolimab.

“We are immensely proud of what Spevigo represents for people living with GPP and bringing innovation to this community of patients has been a powerful reflection of our purpose to transform lives,” said Shashank Deshpande, chairman of the Board of Managing Directors and head of Human Pharma at Boehringer Ingelheim, in a news release.¹ “Spevigo holds a significant promise, and ensuring it reaches its full potential requires continued focus, and expertise in medical dermatology. With over six decades of singular dedication to this field, LEO Pharma is exceptionally well-positioned to build on the strong foundation we’ve laid.”

Christophe Bourdon, CEO of LEO Pharma, echoed the significance of the partnership.

“Skin diseases can profoundly impact people’s lives, and at LEO Pharma, we are here to change that,” Bourdon said.¹ “Partnering to bring Spevigo to more patients is more than a strategic step; it means the opportunity to help people living with GPP by addressing a disease with limited treatment options and aiming to improve their quality of life. Together, we have a powerful opportunity to expand access to innovative care and deliver meaningful progress for patients who have long been underserved.”

References

1. Boehringer Ingelheim and LEO Pharma enter partnership to commercialize and further develop Spevigo (spesolimab). News release. Boehringer Ingelheim. July 14, 2025. Accessed July 14, 2025. https://www.boehringer-ingelheim.com/human-health/skin-and-inflammatory-diseases/gpp/boehringer-leo-pharma-partnership-commercialize-spevigo
2. Marrakchi S, Puig L. Pathophysiology of generalized pustular psoriasis. Am J Clin Dermatol. 2022;23(Suppl 1):13-19. doi:10.1007/s40257-021-00655-y
3. Spevigo approved for expanded indications in China and the US. News release. Boehringer Ingelheim. March 19, 2024. Accessed July 14, 2025. https://www.boehringer-ingelheim.com/us/human-health/skin-and-inflammatory-diseases/gpp/spevigo-approved-expanded-indications-china-and-us
4. Morita A, Strober B, Burden AD, et al. Efficacy and safety of subcutaneous spesolimab for the prevention of generalised pustular psoriasis flares (Effisayil 2): an international, multicentre, randomised, placebo-controlled trial. Lancet. 2023;402:1541–1551.