Affibody Announces New Izokibep Data at EADV 2026 Demonstrating Efficacy Across Patient Subgroups and Stringent Clinical Endpoints

Regulatory

September 30, 2026

Stockholm, Sweden, September 30, 2026. Affibody AB (“Affibody”) today announced new analyses from its global Phase 3 study of the next generation IL-17A inhibitor izokibep in hidradenitis suppurativa (HS), demonstrating consistent efficacy across clinically relevant patient subgroups and stringent measures of disease activity. The data will be presented at the European Academy of Dermatology & Venereology Congress 2026 (EADV) taking place September 30 – October 3 in Vienna.

As previously announced, the Phase 3 study met the primary endpoint of HiSCR75, as well as several key secondary endpoints including HiSCR90 and HiSCR100.

The new analyses demonstrate that patients treated with izokibep consistently achieved higher rates of HiSCR75, HiSCR90 and HiSCR100 at week 16 compared to placebo-treated patients across clinically relevant patient subgroups including, baseline body weight (<100 kg/≥100kg), smoking status (yes/no), baseline Hurley stage (II/III), and prior tumor necrosis factor inhibitor (TNFi) use (yes/no).

At week 32, patients randomized to izokibep had sustained responses across all evaluated subgroups, and patients initially randomized to placebo demonstrated improved response rates following crossover to izokibep.

Dr Martina Porter, investigator in the study, will present the results in an oral presentation at EADV 2026 on Friday, October 2.

“Hidradenitis suppurativa is a highly heterogeneous disease, and there is a medical need for new treatments that can provide deep remission across a broad range of patients,” said Martina Porter, M.D., Department of Dermatology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, USA. “These results show that izokibep delivers clinically meaningful improvements across all evaluated patient subgroups, including patients with severe disease and those previously treated with TNF inhibitors. The consistency of response observed is encouraging and supports the potential of izokibep to benefit a broad HS patient population.”

In a separate analysis of the International HS Severity Score System (IHS4), significantly higher proportions of patients treated with izokibep versus placebo achieved IHS4-55 (49.1% vs 33.6%; p=0.007), IHS4-75 (32.8% vs 18.6%; p=0.005), IHS4-90 (23.6% vs 8.1%; p<0.001), and IHS4-100 (17.5% vs 6.4%; p=0.004) at week 12 using nonresponse/multiple imputation, with similar findings observed at week 16.

Patients who continuously received izokibep continued to improve through week 32 and patients who crossed over from placebo to izokibep at week 16 also achieved notable responses by week 32.

Professor Falk Bechara, investigator in the study, will present the IHS4 data as an ePoster at EADV 2026.

“These new findings reinforce our confidence in izokibep’s potential to offer a differentiated treatment option for patients living with hidradenitis suppurativa,” said David Bejker, Chief Executive Officer of Affibody. “Importantly, izokibep demonstrated clinically meaningful improvements across stringent disease activity measures, with nearly one in five patients achieving complete resolution of all inflammatory lesions already at week 12 as measured by IHS4-100.”

Details about the presentations:
Title: Efficacy of izokibep, a novel interleukin-17A inhibitor, in moderate to severe hidradenitis suppurativa: A patient subgroup analysis from a randomized, double-blind, placebo-controlled, multicenter, phase 3 study.
Date/Time: Friday, 2 October, 14:25 – 14:35 CEST.
Presenter: Martina Porter, M.D., Department of Dermatology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, USA.
Format: Oral
Presentation ID: FC07.1B

Title: IHS4 outcomes to week 32 with izokibep, a novel interleukin-17A inhibitor, in patients with moderate to severe hidradenitis suppurativa: Results from a randomized, double-blind, placebo-controlled, multicenter, phase 3 study.
Presenter: Prof Falk Bechara, M.D., Department of Dermatology, Venereology and Allergology, International Centre for Hidradenitis Suppurativa/Acne Inversa (ICH), Ruhr-University Bochum, Bochum, Germany.
Format: ePoster
Poster ID: P1369

Additional information about EADV 2026 is available at: https://eadv.org/congress/

About izokibep

Izokibep is an Affibody^® molecule designed to selectively inhibit IL-17A with high potency. It is only about one-tenth the size of a monoclonal antibody and has been engineered to reach difficult-to-treat tissues by incorporating an albumin binding domain that also results in improved pharmacokinetic (PK) properties. Clinical trial data support the hypothesis that these unique characteristics of izokibep may provide clinically meaningful and differentiated benefits for patients, including resolution of key manifestations of disease. Izokibep has been administered to more than a thousand patients, some of whom have been dosed for more than three years.

Late-stage trials of izokibep in hidradenitis suppurativa (HS) and psoriatic arthritis (PsA) have demonstrated levels of clinical response comparable with next generation approaches to IL-17 inhibition. These data also demonstrate that targeting IL-17A alone with greater potency can achieve the same or better clinical responses than agents targeting IL-17 subunits more broadly, without their associated safety liabilities.

About the Phase 3 Hidradenitis Suppurativa clinical study

The Phase 3 clinical study (NCT05905783) was a global, multicenter, randomized double-blind, placebo-controlled trial evaluating the safety and efficacy of izokibep dosed subcutaneously 160 mg every week (QW) versus placebo. The study included 258 randomized patients with moderate-to-severe HS. The primary endpoint was the proportion of patients achieving HiSCR75 at week 12. Further endpoints included HiSCR90 and HiSCR100 as well as later timepoints. At week 16, the study was unblinded, and patients receiving placebo were switched to izokibep 160 mg QW.

For more information about the Phase 3 HS clinical study, please visit www.clinicaltrials.gov.

About Hidradenitis Suppurativa

HS is a chronic inflammatory skin disease which typically manifests in areas with high concentrations of sweat glands causing inflammatory nodules, abscesses, draining fistulas, malodor, scarring, and severe pain. HS is a highly burdensome condition that profoundly impairs patients’ quality of life.

HiSCR measures response to treatment in HS with HiSCR75 indicating at least a 75% reduction in total abscess and inflammatory nodule count (AN count), with no increase in abscess count, and no increase in draining fistula count relative to baseline. Higher order measures such as HiSCR90, and HiSCR100 indicate 90%, and 100% reduction respectively.

About Affibody® molecules

Affibody^® molecules are a novel drug class of small therapeutic proteins with characteristics surpassing monoclonal antibodies (mAbs) and antibody fragments. The company has created a large library consisting of more than ten billion Affibody^® molecules, all with unique binding sites, from which binders to given targets are selected. Affibody^® molecules are only 6 kDa in size.

They have demonstrated clinical benefit both as tumor-targeting moieties and as efficacious disease modifying agents in autoimmune indications by utilizing the inherent differentiated properties of the platform.

About Affibody

Affibody is a clinical stage radiopharmaceutical company developing next generation Radioligand Therapies (RLTs) designed to deliver highly selective tumor targeting across a wide range of cancers. Leveraging decades of innovation in Affibody^® molecule discovery and engineering, together with deep understanding of the RLT field, the company is advancing a novel pipeline focused on oncology indications with high unmet medical need. Affibody’s lead RLT candidate, ABY-271, is currently being evaluated in a first-in-human clinical study in HER2-positive metastatic breast cancer.

The Affibody^® platform has also demonstrated clinical value in immunology and inflammation, with multiple programs being advanced through strategic partnerships.

Affibody’s main shareholder, Patricia Industries, is a part of Investor AB.

Further information can be found at: www.affibody.com.

Affibody Announces New Izokibep Data at EADV 2026 Demonstrating Efficacy Across Patient Subgroups and Stringent Clinical Endpoints