Science & Pipeline

Direct inhibition

YB-101 is a potentially first-in-class monoclonal antibody that specifically blocks TSHR, the central target of the immune attack responsible for Graves’ disease (GD) and thyroid eye disease (TED).

The site of action in GD and TED

In the absence of disease, thyroid stimulating hormone (TSH), is secreted by the anterior of pituitary gland and binds to the TSH receptor (TSHR). This binding regulates production of thyroid hormones that direct metabolic processes such as heart rate, thermoregulation, sleep and energy balance. In TED, TSHR is also present expressed in the eye. In both locations, autoantibodies against TSHR attack and overstimulate the receptor which leads to the symptoms of GD and TED.

This mechanism makes TSHR the ideal target for treatments aiming to block the pathophysiology of both GD and TED.

Graves’ Disease

Thyroid gland
Colloid
Disease State TSHR Inhibition
TSH TSH TSHR receptor

TSH
binding site

TSHR

TSHR
autoantibody

YB-101

TED

Orbital fibroblast
Increased thyroid activity
Expanded orbital tissues
Thyroid cell proliferation
Fibrosis
Adipogenesis
Normalized thyroid activity
Inhibition of TED orbital pathology

The advantages of a precision approach

By directly disrupting the central mechanism underlying both GD and TED, YB-101 offers the potential to suppress both thyroidal and extra-thyroidal manifestations of these diseases without the risk of serious toxicities or immunosuppression.

Pipeline

Yarrow is developing YB-101 for the treatment of both GD and TED worldwide with our partner Changchun Genescience Pharmaceutical Company, Ltd. (“GenSci”).

YB-101

in Graves’ Disease

Preclinical
Phase 1
Phase 2

A global Phase 2a/2b trial in patients with Graves’ disease led by Yarrow is underway.

Preclinical
Phase 1
Phase 2

YB-101 (GenSci098) is currently being investigated in a Phase 1 clinical trial in Graves’ disease by our partner GenSci in China.

YB-101

in Thyroid Eye Disease

Preclinical
Phase 1
Phase 2

YB-101 (GenSci098) is currently being investigated in a Phase 1 clinical trial in thyroid eye disease by our partner GenSci in China.