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KDDF-201812-09 Development of HDAC6 inhibitor (CKD-506) for the treatment of Rheumatoid arthritis(Immunology, Chemical) [2020-06-24]

Ongoing Project
Section Lead
Preclinical Phase I Phase II Phase III

Development and Market Objectives

The goal of this project includes phase IIa study in patients with rheumatoid arthritis (RA) who had an inadequate response to methotrexate (MTX) and long term GLP-toxicology study and DS/DP study for Phase IIb.

Unmet Medical Need & Target Patients

RA is a chronic autoimmune disorder which affects 1% of adults in the developed world. The market size of RA is bigger than any other autoimmune diseases. The guideline for RA treatment recommends using MTX as a 1st therapeutic but around 30~40 % of patients do not have a good response to MTX single treatment and then switch to other therapeutics such as conventional- or biological- disease modifying anti-rheumatic drugs (cDMARD or bDMARD) in combination with MTX. However, cDMARDs are not fully satisfied therapeutics and bDMARDs develop neutralization antibodies which lead to loss of therapeutic effects in patients with RA. Moreover, oral JAK inhibitors which recently released in RA market have been reported that significantly induced LDL cholesterol and increased the risk of cardiovascular events. Therefore, a drug with new mechanisms should be developed as a novel therapeutic for RA patients.

In animal models of RA, CKD-506 showed good therapeutic efficacy and strong synergism in combination with MTX, suggesting that CKD-506 with MTX may have synergistically therapeutic effects in patients with RA.

Therefore, the 1st targeted population is an inadequate responder to MTX therapy, but we consider other patients with inadequate responders to other DMARD for the next therapeutic since they have no option for therapeutics.


In animal models of RA, CKD-506 showed good therapeutic efficacy and strong synergism in combination with MTX. In addition, CKD-506 inhibited TNFα and induced Treg activity of PBMCs of RA patients. Mechanistically, CKD-506 inhibited HDAC6 induced inflammatory responses in macrophages and induced CTLA4 expression in mouse Treg cells.

In PI clinical study, CKD-506 is safe and well tolerable and confirmed dose-dependent increased pharmacokinetics and pharmacodynamics in healthy volunteers.

Intellectual Property

Novel compounds for selective histone deacetylase inhibitor, and the pharmaceutical composition comprising thereof. The patent of CKD-506 was granted in Korea, and filed in 53 countries.

Competitive Advantages

CKD-506, an oral small molecule, has dual action mechanisms that inhibits inflammation especially TNFα and induces CTLA4 in Treg cells. These targets are representative therapeutics for patients with RA now. Moreover, CKD-506 has synergistic efficacy with MTX combination. Unlike JAK inhibition mechanisms, CKD-506 does not induce LDL cholesterol and decrease white blood cells.   

Contact & Company Overview

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