There are also trials evaluating the efficacy of spesolimab for palmoplantar pustulosis. A pilot study (Mrowietz et al, 2021) found that spesolimab was well tolerated but did not meet the primary endpoint for efficacy in treating palmoplantarpustulosis. A phase IIb trial is underway.
Spesolimab is a humanised monoclonalantibody that binds to interleukin 36 (IL-36) receptors and prevents binding of IL-36, preventing activation of proinflammatory pathways.
As the IL-36 pathway is integral in the pathogenesis of GPP, its downregulation is proposed to help relieve GPP flares.
IL-36 has also been shown to play a role in the pathogenesis of palmoplantar pustulosis, and the use of spesolimab in this context is being investigated.
Spesolimab dosing and administration
Administered as a single 900mg dose (diluted prior to administration in sterile 0.9% sodium chloride injection) by intravenous (IV) infusion over 90 minutes.
Not to be combined with other medications during infusion.
The infusion should be discontinued if a reaction occurs. In the case of mild reaction, restarting the infusion at a slower rate (over maximum 180 mins) can be considered.
If GPP symptoms persist, an additional 900mg dose one week after the initial dose can be given.
What are the benefits of spesolimab?
Effisayil-1, a phase II, multi-centre, randomised, double-blind, placebo-controlled trial (Bachelez et al, 2021), examined the efficacy of spesolimab in 53 patients with moderate-to-severe generalised pustular psoriasis (GPP) flares.
Spesolimab was associated with a higher incidence of lesion clearance at 1 week compared to placebo, as assessed using the GPP Physician Global Assessment (GPPGA) score.
To be eligible for randomisation, patients had to have a GPPGA score of ≥3.
One week after administration of either 900mg IV spesolimab or placebo, 54% of patients in the spesolimab group had a pustulation subscore of 0, compared to 6% in the placebo group (p <0.001).
What are the potential side effects of spesolimab?
Reported side effects in patients given spesolimab include:
In the 12-week assessment extension period of Effisayil-1 trial (Bachelez et al, 2021), 47% of the 51 patients who received at least 1 dose of spesolimab reported infection, including UTI, upper respiratory tract infection, influenza, otitis externa, and folliculitis
There is limited or no data on the use and safety of spesolimab in pregnant, breastfeeding, paediatric, or geriatric patients.
What are the contraindications to spesolimab?
Severe or life-threatening hypersensitivity to spesolimab or its excipients.
Do not give spesolimab during clinically significant active infection, including active tuberculosis infection.
Approved datasheets are the official source of information for medicines, including approved uses, doses, and safety information. Check the individual datasheet in your country for information about medicines.
Bachelez H, Choon SE, Marrakchi S, et al. Inhibition of the Interleukin-36 Pathway for the Treatment of Generalized Pustular Psoriasis. N Engl J Med. 2019;380(10):981–3. doi 10.1056/NEJMc1811317. Journal
Bachelez H, Choon SE, Marrakchi S, et al. Trial of Spesolimab for Generalized Pustular Psoriasis. N Engl J Med. 2021;385(26):2431–40. doi 10.1056/NEJMoa2111563. Journal
Mrowietz U, Burden AD, Pinter A, et al. Spesolimab, an Anti-Interleukin-36 Receptor Antibody, in Patients with Palmoplantar Pustulosis: Results of a Phase IIa, Multicenter, Double-Blind, Randomized, Placebo-Controlled Pilot Study. Dermatol Ther (Heidelb). 2021;11(2):571–85. doi 10.1007/s13555-021-00504-0. Article
Pang Z, Wu C, Liu J, Liu Y, Jin H. Spesolimab Response in a Patient With Steroid-Resistant Sweet Syndrome. JAMA Dermatol. 2025;161(1):110-112. PubMed