Citryll BV, based in Oss, The Netherlands, has successfully closed an oversubscribed €85 million Series B funding round, building on its €18.5 million Series A round from 2020. The financing will propel the clinical development of CIT-013, a novel monoclonal antibody targeting Neutrophil Extracellular Traps (NETs).
The funding round was co-led by Johnson & Johnson Innovation, Forbion, and Novartis Venture Fund, with participation from Pureos Bioventures and existing investors including BioGeneration Ventures, Seventure Partners, BOM, Curie Capital, and Citryll’s founders from ModiQuest BV.
Targeting NETs with CIT-013
CIT-013 is designed to bind to Histone 2A and Histone 4, key components of NETs. NETs are mesh-like structures composed of DNA, histones, and antimicrobial proteins released by neutrophils to trap and degrade pathogens. However, excessive NET formation can lead to tissue damage and chronic inflammation in various immune-mediated inflammatory disorders, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and hidradenitis suppurativa (HS).
Unlike broad-spectrum anti-inflammatory or immunosuppressive therapies, CIT-013 selectively targets and clears NETs while inhibiting the formation of new ones. This dual mechanism of action aims to extinguish the source of autoantigens, such as NET-derived toxic, prothrombotic, and proinflammatory components, and citrullinated histone proteins, without affecting normal intracellular functions.
Clinical Development and Trial Design
Citryll has completed Phase I studies, including successful repeat dosing in eight rheumatoid arthritis (RA) patients. The company is now planning Phase IIa trials in both RA and hidradenitis suppurativa (HS). These trials are designed to establish CIT-013’s unique dual mechanism of action, demonstrating its ability to clear existing NETs and inhibit the formation of new NETs.
CIT-013 exhibits high selectivity for its epitope, minimizing off-target effects. The antibody does not enter cells, preserving normal intracellular functions. While the initial focus is on RA and HS, Citryll’s NET-targeting approach has potential applications across a wide range of immune-mediated inflammatory diseases, including sepsis, acute respiratory distress syndrome (ARDS), acute lung injury (ALI), systemic lupus erythematosus (SLE), vasculitis, antiphospholipid syndrome (APS), and asthma.
Leadership and Future Directions
Following the Series B round, Geert-Jan Mulder, Managing Partner at Forbion, Florian Muellershausen, Managing Director at Novartis Venture Fund, and a representative of JJDC will join Citryll’s Board as non-executive directors. This infusion of capital and expertise will support Citryll's efforts to advance CIT-013 through clinical development and explore its potential in various immune-mediated inflammatory diseases.
