Rigel has focused its RA program on the development of oral, safe, disease modifying anti-rheumatic drugs (DMARD’s). In December 2007, Rigel announced significant and rapid improvement in RA patients in a Phase 2 clinical trial that showed higher ACR20, ACR50, and ACR70 scores than placebo. This data was reconfirmed in a Phase 2b trial in July 2009.

ITP is an autoimmune-based hematological diseases characterized by the destruction of platelets. Rigel’s lead product candidate, R788, may address platelet destruction by inhibiting IgG signaling. In November 2007, we released initial results from our Phase 2 ITP trial showing that R788 increased platelet counts for a majority of the patients treated.

Diffuse large B-cell lymphoma is the most common type of non-Hodgkins lymphoma. Research has shown that R788 effectively interrupts the growth of B-cells and signaling proteins that contribute to the survival of these tumors. In December 2008, results in our Phase 2 clinical study showed the benefit of R788 in Diffuse Large B-Cell and SLL/CLL lymphomas. Rigel has also initiated a Phase 2 clinical trial in T-cell lymphomas.

R763 is a potent, selective Aurora kinase that has been shown to inhibit proliferation and trigger apoptosis in several tumor cell lines, including cervical, colon, lung, pancreas and prostate. Rigel partnered with Merck Serono to develop R763, in a deal worth $160M. Merck Serono has initiated three Phase 1 studies of R763.

Rigel is investigating Syk kinase inhibitors, which are designed to block all of the major pathways triggered in an allergic attack, for the treatment of asthma. In May 2006, Pfizer selected R343 for advanced preclinical development. In December 2007, Pfizer initiated Phase 1 trials with R343. Both of these events triggered $5 million milestone payments.