Rigel Pharmaceuticals' results from a comparative phase II clinical study of R112, a potential intranasal therapy for the treatment of allergic rhinitis were disappointing. The randomised, double-blind study compared R112 and Beconase AQ (beclomethasone) nasal spray to placebo, over a 7-day period.

In the trial, treatment with R112 failed to show a statistically significant difference from placebo treatment in improving nasal allergy symptoms, the study's primary endpoint. Beconase AQ was superior to placebo treatment.

"We are disappointed in today's results. These results are surprising given that the earlier phase II 'Park' study of R112 demonstrated a statistically significant reduction in the symptoms associated with allergies," said James M. Gower, chairman and chief executive officer of Rigel.

The phase II study was conducted at 25 centres across the United States and enrolled 396 patients who had experienced seasonal allergic rhinitis during the summer/fall pollen season for the last two years. The primary endpoints were safety and efficacy, as measured by a total nasal symptom severity (TNSS) rating scale, a scale of five nasal symptoms including congestion, runny nose, sneezing, itchy nose and postnasal drip. The trial consisted of a screening period during which the patients stopped taking any allergy medications, followed by a placebo run-in period. The patients were then randomized to a 7-day treatment cycle of twice daily dosing of R112, placebo or Beconase AQ.

Allergic rhinitis involves inflammation of the mucous membranes of the nose, eyes, ear, sinuses and pharynx. This inflammation is characterised by a complex interaction of inflammatory mediators, but ultimately is triggered by an immunoglobulin E (IgE)-mediated response to a foreign allergen.

Rigel is a clinical-stage drug development company that discovers and develops novel, small-molecule drugs for the treatment of inflammatory diseases, cancer and viral diseases.