• Rigel is targeting asthma and allergy using its advanced technology to develop significantly improved therapeutics for the more than 11 million people in the U.S. with asthma, and the more than 59 million people suffering from allergic disorders.


• Rigel’s syk kinase inhibitors are designed to block all of the major pathways triggered in an allergic attack, potentially resulting in more effective and comprehensive drugs.


• Rigel and Pfizer are collaborating to advance small molecule compounds to the clinic for the treatment of asthma and chronic obstructive pulmonary disease (COPD) via intrapulmonary delivery.

• In December 2007, Pfizer initiated Phase 1 studies with R343 in allergic asthma.


• In May 2006, Pfizer selected R343 for advanced preclinical development in allergic asthma.

• Rigel Announces Initiation of Phase 1 Clinical Trial of R343 for Allergic Asthma by its Partner Pfizer


• Rigel Announces Pfizer Selection of R343, a Syk Kinase Inhibitor, for Advanced Preclinical Development in Allergic Asthma

Disease background
Asthma and allergic rhinitis are chronic inflammatory disorders of the airways. Asthma affects the lower respiratory tract and is marked by episodic flare-ups, or attacks, that can be life threatening. Allergic rhinitis, or allergy, is an acute inflammatory reaction in the upper respiratory tract resulting in nasal congestion, sneezing, itching and watery eyes.

In some patients, allergens, such as pollen, trigger the production of immunoglobulin E antibodies, or IgE antibodies, which then bind to mast cells and cause an intracellular signal that results in the release of various chemical mediators. When this process occurs repeatedly over time, it creates persistent inflammation of the airway passages, resulting in airway obstruction and the chronic congestion associated with asthma and allergic rhinitis, respectively.