NEW YORK - Shares of Rigel Pharmaceuticals tumbled Monday after the company reported a potential asthma treatment failed to meet any of its goals in a mid-stage clinical trial.
Rigel said the clinical trial was designed to compare the effect of its treatment R343 to that of a placebo on patients' lungs. Based on the results Rigel does not plan to continue studying the drug as a treatment for asthma.
Shares of the South San Francisco, Calif., company lost 40 cents, or 11 percent, to $3.23 in morning trading. Earlier they fell to an all-time low of $3. Shares of Rigel are down about 70 percent since their 52-week high of $10.95 last September.
Rigel Pharmaceuticals Inc. does not have any approved drugs.
Its most advanced product is fostamatinib, a potential treatment for rheumatoid arthritis. In December Rigel and its partner AstraZeneca reported mixed results from a mid-stage trial of the drug, and in April they reported similar results from late-stage studies. In June British drugmaker AstraZeneca PLC ended a partnership with Rigel, deciding it would not try to get marketing approval for fostamatinib.
Rigel is also studying a lupus treatment called R333 and a drug called R348 as a treatment for dry eye.