Shares in Oxford-based Circassia Pharmaceuticals PLC (LON:CIR) slumped after its cat allergy treatment did little better than the placebo in a Phase III trial.
The pharma company said it would stop the registration study of its grass allergy treatment, as well as the preparatory work for a dose-ranging study of its ragweed allergy therapy.
“We are surprised and disappointed by these results,” said chief executive Steve Harris.
Patients reacted well to its treatment, but they also did to the dummy drug so the trials were not able to conclusively identify the effect of the treatment.
“Such a placebo effect was not a feature of our earlier phase II studies. However, in this large-scale trial it eliminated our ability to identify a treatment effect," Harris added.
The firm will now analyse the full set of results to determine and address the implications for its wider allergy pipeline.
Circassia was keen to stress that its wider respiratory franchises are unaffected by the results, and that it will continue growing its NIOX asthma management products.
Cat-SPIRE is the most advanced of Circassia’s immunotherapy pipelines which use short peptides to induce immune tolerance with a lower risk of side effects.
The Phase III CATALYST study compared a four-dose course of Fel d 1 allergen peptides, two sequential courses (eight doses) and placebo.
All of the study groups had a greatly improved combined total rhinoconjunctivitis symptom score (TRSS) versus baseline – 58.2% for the 4 dose course, 59.8% for the eight dose course, and 58.5% for placebo.
The company added that it had over £139mln in cash as of 31 May.
Shares were down 178p, or 66%, to 92p.
-- Update: Share price --
-- Update: Background info --