CIR.L Regulatory News (CIR)

Circassia Announces Top-Line Results from Ragweed Allergy Treatment Phase IIb Chamber Study

Oxford, UK - 8 December 2014: Circassia Pharmaceuticals plc ("Circassia" or "the Company"; LSE: CIR), a specialty biopharmaceutical company focused on allergy, today announces results from a phase IIb chamber study of its ragweed allergy product candidate, Ragweed-SPIRE. In the study, subjects in the optimal treatment group had improved allergy symptoms, compared with both baseline and placebo. In addition, there was a clear dose-response effect, with subjects who received the highest dose of Ragweed-SPIRE experiencing the greatest reduction in symptoms. Currently, Circassia has received top line results only from the study, and the Company intends to review the full dataset in the coming weeks.

Study overview (TR006)

The randomised, double-blind, placebo-controlled phase IIb study included 280 subjects with ragweed allergy. Subjects received placebo or one of three Ragweed-SPIRE short-course regimens (4 x 6 nmol; 8 x 6 nmol; 8 x 12 nmol), which were completed prior to the start of the ragweed pollen season. After the peak of the season, the subjects recorded their nasal and non-nasal symptoms (Total Rhinoconjunctivitis Symptom Score (TRSS)) while exposed to ragweed pollen in an environmental exposure chamber. The study's primary efficacy endpoint was a comparison of the improvement in TRSS from baseline for each Ragweed-SPIRE regimen vs placebo, with secondary endpoints comparing improvements in nasal (TNSS) and non-nasal (TNNSS) symptoms. Subjects included in the study required a mean baseline TRSS of greater than or equal to 12 points.

Study results

· The optimal treatment regimen (8 x 12 nmol; n=70) achieved an improvement in mean TRSS from baseline of 4.72 points and an improvement vs placebo of 1.25 points (p=0.149);

· The treatment regimens demonstrated a clear dose-response effect, with both of the lower doses reducing TRSS from baseline and vs placebo, although at a lower level than that achieved by the higher dose;

· There was a marked placebo effect in the study, which was greater than that seen in comparable subjects in the previous Ragweed-SPIRE phase II study;

· There was a similar response pattern in the secondary endpoints, with greater reductions in nasal than non-nasal symptoms, compared with both baseline and placebo (8 x 12 nmol mean TNSS reduction of 2.42 points from baseline and 0.69 points vs placebo; p=0.095); and

· Ragweed-SPIRE was well-tolerated with no significant safety issues.

Next steps

Circassia has top line results only from the study, and in the coming weeks will examine the full dataset. The Company will:

· Evaluate whether any specific circumstances influenced the study outcome;

· Review the opportunity to conduct a follow-up study in subjects in the optimal treatment group to assess the effect of a booster course of treatment; and

· Utilise the full dataset to inform the design of a potential higher-dose escalation study.

Steve Harris, Circassia's Chief Executive, said: "These results follow the earlier proof-of-concept data we achieved with our ragweed allergy treatment, and confirm the potential of our product candidate to improve allergy symptoms. The clear dose-response effect is consistent with our short-course of treatment having a positive effect on subjects' symptoms. 

We did not test a higher dose than that used in our previous Ragweed-SPIRE study, based on learnings from our other programmes. However, the results from this new study, and the greater efficacy seen with our other product candidates, indicate that there are doses we have not yet explored that could produce a greater response.

Currently, we have top line results only from this recent study, and in the coming weeks we intend to review the full dataset, including the dose-response data, to inform the next steps in our Ragweed-SPIRE development programme. In parallel, we will pursue the potential to conduct a follow-up booster study, to ensure we maximise the learnings we can take from this trial, and provide further valuable data to inform a potential future higher-dose escalation study."

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Notes to editors

Circassia

Circassia is a specialty biopharmaceutical company focused on the development and commercialisation of a range of allergy immunotherapy product candidates. Established in 2006, the Company has used its proprietary ToleroMune® technology to develop a new class of therapies, the Synthetic Peptide Immuno-Regulatory Epitopes (SPIREs), which have the potential to revolutionise allergy treatment.

The Company's portfolio of SPIREs is designed to treat a broad range of seasonal and perennial allergies. The most advanced, Cat-SPIRE, targets cat allergy and is currently in phase III development. Three other product candidates, targeting house dust mite, ragweed and grass allergies, have completed clinical proof-of-concept phase IIb studies.

As Circassia continues to grow, the Company remains focused on its founding principle - a commitment to improving patients' lives by controlling immune responses. Further information is available at: www.circassia.co.uk.