Rigel Plunges 18% As R343 Fails To Meet Goals In Mid-stage Asthma Study

(RTTNews) - Shares of Rigel Pharmaceuticals, Inc. (RIGL) plunged nearly 18 percent in pre-market trading on Monday after the clinical-stage drug development company's R343 failed to meet primary or secondary endpoints in a mid-stage clinical study as a potential therapeutic for patients with allergic asthma. The company has now decided not to pursue this indication with R343.

"This was not the result we expected based on the collection of data we had previously seen with R343 in this therapeutic area. Fortunately, we have a robust portfolio of clinical and preclinical research programs to focus on that includes Fostamatinib, R333 for discoid lupus erythematosus and R348 for dry eye," Chairman and CEO James Gower said in a statement.

R343 is an inhaled small molecule SYK kinase inhibitor for the treatment of allergic asthma. Rigel had a collaborative research and license agreement with Pfizer for R343 that was signed in 2005. The agreement was terminated in 2011 and Rigel gained full rights to the R343 program.

The South San Francisco-based company commenced the Phase 2 clinical studies in early September 2012. The study saw about 270 adults with allergic asthma being randomized into the three arms of this Phase 2 clinical study of R343, called SITAR (SYK Inhibition for Treatment of Asthma with R343), for eight weeks of treatment with either of two different doses of the study agent or placebo.

The primary endpoint of this double-blind, multi-center study was the measurement of each patient's change in pre-bronchodilator FEV1, a measure of lung function, from baseline to dosing completion at week 8, comparing active doses to placebo. Rigel used the 3M Taper Dry Powder Inhaler device for this trial.

Allergic asthma is a chronic inflammatory disorder of the lungs and respiratory passages caused in response to an allergen or pathogen. In severe cases or episodes, this disorder can cause breathlessness, tissue scarring and/or death from asphyxiation.

The Asthma and Allergy Foundation of America estimates that 20 million people in the U.S. have asthma; the majority of them classified as allergic asthma. Despite the currently available therapies, approximately 25%, or approximately 2 million, of all Emergency Room visits each year are attributed to acute and severe episodes of this disease.

Rigel has no marketed drugs, and currently, its only potential sources of revenue are upfront payments, research and development contingent payments and royalty payments pursuant to its collaboration arrangements.

RIGL closed Friday's regular trading session at $3.63, unchanged on a volume of 0.14 million shares.