Circassia is a clinical-stage speciality biopharmaceutical company focused on the development and commercialisation of a range of novel immunotherapy products for the long-term treatment of common allergies.


Circassia is developing a portfolio of novel immunotherapy products for the long term treatment of common allergies through short treatment courses with its SPIRE (synthetic peptide immune-regulatory epitope) therapies. Clinical studies conducted by the Company have demonstrated the potential of its product candidates to deliver an effective short course (of either four or eight injections over three months) immunotherapy with minimal side-effects and long-lasting benefits. These are significant benefits over the current treatment options available to allergy sufferers. The company’s proprietary ToleroMune® platform technology is based on technology originally developed at Imperial College London.

Circassia’s lead product, Cat-SPIRE (a new treatment for cat allergy), is currently in a pivotal Phase III registration study. The trial is fully recruited and is due to report out in H1 2016. A positive outcome of this trial is likely to represent a substantial value inflection point for the business. Three other products developed to treat a broad range of seasonal and perennial allergies (house dust mites, grass and ragweed) have completed clinical proof-of-concept Phase IIb studies.

The Company has demonstrated clinical proof-of concept for each of its four lead product candidates, Cat-SPIRE (for the treatment of cat allergy), HDM-SPIRE (for the treatment of house dust mite allergy), Grass-SPIRE (for the treatment of grass allergy) and Ragweed-SPIRE (for the treatment of ragweed allergy). Circassia has completed a phase IIb study for each of HDM-SPIRE, Grass-SPIRE and Ragweed-SPIRE. The Company expects that phase III data for each of these product candidates will be available in 2017. Circassia is also developing product candidates for the treatment of allergies to Birch, Alternaria (a common type of mould) and Japanese cedar, which are each in earlier stages of development.

Circassia’s SPIRE products are developed using its proprietary ToleroMune® technology, which uses small sections of allergens (epitopes) to generate regulatory T-cells, which suppress allergic immune responses, leading to the rapid development of immune tolerance without the long duration of treatment and the adverse reactions seen with conventional whole allergen immunotherapy.

Circassia listed on the main market of the London Stock Exchange on the 18th March 2014, raising £200 million at a market cap of £581.0 million, in one of the UK's largest ever biotech floats. The company trades under the ticker CIR.


Peak product sales for Circassia’s four lead products has been estimated at $2.5 billion per year by external consultants. This has been corroborated by further research by which estimates that the market for Circassia’s cat product alone is over $0.6 billion. The global market for allergy treatments is currently underserved, despite large numbers of sufferers: more than 150 million people suffer from allergic rhinitis in the US and Europe, and the total treatment market for allergies is estimated at $12 billion per year.

Investment History

Circassia has raised a total of £580 million from private investors and the public markets. Prior to its IPO in 2014, Circassia had raised £105 million from a syndicate of private investors. During its IPO, it raised £200 million and in May 2015 it raised a further funding round of £275 million to fund its acquisition of Aerocrine and Prosonix.

These acquisitions transform the enlarged Circassia into a leading speciality biopharmaceutical company focused on the diagnosis, treatment and management of allergy, asthma and chronic obstructive pulmonary disease (COPD).

Crucially, the acquisition of Aerocrine provides an opportunity to leverage its existing sales structure in US and Germany, which will form the basis of Circassia’s own commercialisation strategy ahead of the planned launch of its own SPIRE products in 2017.

Our investment

% share holding

Total funding raised

Carrying value

Imperial College London

Investment stage

Imperial Innovation news

Key milestones

  • November 2015

    Receives first marketing approval for its fluticasone propionate pressurised metered dose inhaler using only in vitro results.

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  • June 2015

    Circassia acquires Aerocrine Limited and Prosonix Limited

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  • June 2015

    Circassia completes placing and raises £275 million to fund acquisitions of Aerocrine and Prosonix

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  • January 2015

    Recruitment for pivotal phase III trial for cat allergy treatment complete

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  • June 2014

    Positive top-line results for a phase IIb clinical study of HDM-SPIRE, a house dust mite allergy product candidate based on Circassia’s proprietary ToleroMune® platform technology.

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  • March 2014

    Circassia admitted to trade on the London Stock Exchange

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  • October 2013

    Grass allergy treatment achieves significant system reduction during Hay Fever season

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  • September 2013

    Short course house dust mite allergy treatment achieves significant long-term symptom reduction

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  • February 2013

    Toleromune cat allergy treatment shown to maintain symptom improvement two years after the start of short course therapy

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  • December 2012

    Circassia receives outstanding abstract awards at 2012 World Allergy Organization International Scientific Conference

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  • October 2012

    Start of pivotal phase III Toleromune trial in Cat Allergen-Induced Rhinoconjunctivitis

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  • August 2012

    Joint venture with McMaster University initiates clinical studies to explore biomarkers of Toleromune treatment effectiveness

  • June 2012

    NIH Awards $6.4 Million to Professor Mark Larché to Investigate Mechanisms of Allergy Tolerance Generated by Circassia’s ToleroMune® Treatment

  • April 2012

    Draws down £35m funding from investors following milestone completion and raises further £12m

  • March 2012

    Ragweed allergy therapy achieves positive phase II clinical results

  • March 2012

    Circassia Successfully Completes Observational Study to Inform Design of Cat Allergy Treatment Phase III Trial

  • January 2012

    Announces grant of european patents for key peptides in grass and ragweed allergy therapies

  • September 2011

    Positive phase II trial results for Toleromune hayfever vaccine, which substantially improved patients’ allergy symptoms

  • April 2011

    Circassia announces £60m fundraising

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Imperial Innovations key people

Russ  Cummings Russ  Cummings
Russ Cummings Chief Executive Officer View profile

Key people from Circassia

Steve Harris Steve Harris
Steve Harris CEO/Co-founder View profile
Charles Swingland Charles Swingland
Charles Swingland Deputy Chairman, General Counsel & Co-founder View profile
Julien Cotta Julien Cotta
Julien Cotta Chief Financial Officer View profile
Rod Hafner Rod Hafner
Rod Hafner Senior Vice President Research & Development View profile
Stewart Sharpe Stewart Sharpe
Stewart Sharpe Vice President Commercial Operations View profile
Ian Crosbie Ian Crosbie
Ian Crosbie Senior Vice President Corporate Development View profile