Citryll Doses First Patient in Phase IIa Trial of CIT-013 for Hidradenitis Suppurativa
Key Insights
Citryll (search) has dosed the first patient in its Phase IIa "Citylights" trial evaluating CIT-013, a first-in-class monoclonal antibody targeting extracellular traps (search), for moderate-to-severe hidradenitis suppurativa (search).
The multi-center, randomized, placebo-controlled study will assess two dose levels of CIT-013 in 96 participants over 12 weeks across North America and Europe.
Hidradenitis suppurativa (search) affects approximately 2% of the US and European population, causing recurring painful skin lesions and pus-draining tunnels with limited current treatment options.
Citryll (search) has dosed the first patient in its Phase IIa clinical trial evaluating CIT-013, a first-in-class monoclonal antibody, for the treatment of moderate-to-severe hidradenitis suppurativa (search) (HS). The milestone marks the initiation of the company's second Phase IIa trial this year, following the start of a rheumatoid arthritis (search) study in September 2025.
Novel Therapeutic Approach for Underserved Disease
The "Citylights" trial is a multi-center, double-blind, randomized, placebo-controlled study designed to investigate two dose levels of CIT-013 in 96 participants over a 12-week period across Europe and North America. The study will assess efficacy, safety, and tolerability of the novel antibody in patients with moderate-to-severe HS.
Hidradenitis suppurativa (search) is a debilitating, chronic autoimmune disease affecting approximately 2% of the population in the US and Europe. Patients with the disease suffer from recurring, painful skin lesions with nodules and pus-draining tunnels, leading to scarring, irreversible tissue destruction and decreased quality of life. Despite its prevalence, there are currently limited approved treatment options, and these often fall short in providing adequate disease control.
Targeting Extracellular Traps
CIT-013 represents a potentially transformative therapeutic strategy by targeting extracellular traps (search) (ETs), a key driver of inflammation in HS, rheumatoid arthritis (search), and other immune-mediated inflammatory diseases that has yet to be addressed therapeutically. The antibody employs a unique dual mechanism of action, enhancing the clearance of existing extracellular traps while inhibiting the formation of new ones.
The highly selective antibody minimizes off-target effects and goes beyond individual pathway management and symptom treatment, potentially creating a new class of therapeutics with broad applications across immune-mediated inflammatory diseases.
Clinical Advisory Board Established
To support this clinical advancement, Citryll (search) has established a Clinical Advisory Board bringing together global experts in the field. The board includes Dr. James Krueger, Head of the Laboratory for Investigative Dermatology at The Rockefeller University in New York; Dr. Alexa Kimbal, Professor of Dermatology at Harvard Medical School; and Dr. John Frew, Clinical Dermatologist and Director of Research at The Skin Hospital in Sydney, Australia.
"This is an exciting period for Citryll (search), initiating this HS trial a few months after starting our Phase IIa trial in rheumatoid arthritis (search)," said Maarten Kraan, Chief Medical Officer of Citryll. "As we advance our investigation of CIT-013 in HS, we look forward to drawing on the expertise of our newly formed Clinical Advisory Board. Underpinning all this work is our desire to deliver a novel, disease modifying therapy for the many HS patients who currently lack suitable treatments."
Dr. Falk Bechara, lead investigator of Citylights, added, "I am looking forward to advancing this Phase IIa trial, which marks an important step towards delivering effective treatments for HS, a debilitating disease, where treatment options remain limited. CIT-013's novel, ET-targeting approach offers the potential to improve disease control in HS and address a broad range of inflammatory conditions."
Development Timeline
The current trial follows Citryll (search)'s completion of subject dosing in the repeat-dose stage of the Phase I clinical trial of CIT-013 in July 2024. The company's Phase IIa trial in rheumatoid arthritis (search) was initiated earlier this year, demonstrating the broad potential of the extracellular trap-targeting approach across multiple immune-mediated inflammatory conditions.