Rigel Pharmaceuticals today announced that R348, its ophthalmic JAK/SYK inhibitor, did not meet the primary or secondary endpoints in a recently completed Phase 2 clinical study in patients with dry eye disease.  The endpoints were measured by changes in corneal fluorescein staining, conjunctival staining, tear production and dry eye symptom scores from baseline over 12 weeks of treatment versus placebo. No significant adverse events were reported in the trial.  Rigel has decided not to initiate any new studies of R348 for this indication, but is continuing its Phase 2 study of dry eye in patients with graft versus host disease (GvHD).

The company is focusing its resources on advanced clinical studies of fostamatinib in two indications.  The fostamatinib programs include a recently initiated Phase 3 study in patients with immune thrombocytopenic purpura (ITP) and its planned Phase 2 study in patients with IgA Nephropathy (IgAN), an autoimmune disease of the kidneys, in Q4 2014.  “Demonstrating clinical benefit in patients with dry eye disease remains a significant challenge for the pharmaceutical industry,” said James M. Gower, chairman and chief executive officer of Rigel.  “Our energies and resources going forward are committed to supporting fostamatinib in its advanced clinical development,” he added.

In addition, Rigel announced it has discontinued its indirect AMPK activator program, R118, due to its side-effect profile in Phase 1 clinical trials.  However, the company will continue its direct AMPK activator research program.