R343 - asthma

Unparalleled Innovation in Asthma:

• Rigel's R343 is an inhaled syk kinase inhibitor designed to block the major pathways triggered by asthma, potentially resulting in a more effective and comprehensive drug.


• About 25 million people in the U.S. suffered from asthma in 2009 (8% of the population) (source: CDC).


• A Phase 2 clinical study of R343 was initiated in Q3' 2012. Rigel expects results in mid 2013.

Latest News:

• Rigel Announces Fourth Quarter and Year End 2012 Financial Results


• Rigel Initiates Phase 2 Clinical Studies with R343 for Asthma and R333 for Discoid Lupus

Asthma and Syk background
Allergic asthma is a chronic inflammatory disorder of the lungs and respiratory passages caused in response to an allergen or pathogen. In patients with this disorder, allergens, such as pollen, trigger the production of immunoglobulin E (IgE) antibodies, which then bind to mast cells (the body's defense system gatekeeper) and spark a cascade of intracellular signals to mount an immune response resulting in swelling and inflammation of the airways.

Syk is a protein tyrosine kinase that plays a pivotal role in IgE receptor signaling in mast cells. Rigel’s R343 is designed to bind to the syk in mast cells to interrupt the signal from the IgE receptors. R343’s ability to inhibit syk potentially prevents or stops the immune response to the allergen and may be effective in the short and long-term control of allergic asthma. R343 is delivered into the lung via the inhalation route.