About Citryll

Citryll is a private pharmaceutical company based in Oss, the Netherlands at the Pivot Park , that is dedicated to the development and commercialization of antibody therapeutics that target innate immunity in particular NETosis and NETs.

Citryll was founded by Helmuth van Es, and Renato Chirivi of ModiQuest B.V., CSO of Citryll and co-inventor of tACPA. ModiQuest B.V. and Citryll’s antibody development program is based on the unexpected discovery of immunoglobulins with anti-inflammatory activity in immunoglobulin repertoires of rheumatoid arthritis patients. Its lead molecule CIT-013 is currently being produced by Lonza and first in man studies have started in 2021.

Citryll, is taking a new approach to treat autoimmune and other human diseases like lupus, vasculitis, pulmonary fibrosis, rheumatoid arthritis and organ damage due to sepsis, by targeting and inhibiting the source of auto-antigens and neutrophil extracellular trap (NET) derived toxic molecules instead of broadly targeting inflammation or acquired immunity. The latter are the MoAs of the current medicines like anti-TNF antibodies, small molecule Jak inhibitors and antagonists of B cell biology like anti-CD20 antibodies. 


Citryll’s lead programme targets the formation of NETs and its pathological consequences. NETs are a part of the innate immune system. Inhibition of NET function and/or formation inhibits the release of pro-inflammatory proteins,  citrullinated autoantigens as well the release of toxic histones and autoimmune complexes. Citryll’s programme does so by interfering with formation, function and clearance of NETs and NET components downstream of the protein citrullination pathway catalyzed by peptidylarginine deiminase (PAD) enzymes.

The PAD pathway is  essential for the formation of NETs.  tACPA binds to N-terminal citrullinated epitopes in histones that are essential for NET formation. We believe that drugs that block NET based auto-antigen production and promote the systemic clearance of NETs have the potential to create game changing new treatments to prevent or treat human diseases with high medical need like SLE, vasculitis and organ damage due to sepsis and many other indications.