Circassia is a clinical-stage specialty biopharmaceutical company focused on the development and commercialisation of a range of novel immunotherapy products for the 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 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). Cat-SPIRE is in an ongoing phase III registration study and the Company expects to have the results available by H1 2016. Subject to the results of this phase III registration study, the Company intends to submit applications to the FDA, Health Canada and the EMA for marketing approval for Cat-SPIRE in H2 2016 and use this data to support applications in other territories. The Company 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. The Company 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 £105 million in private rounds from investors including Imperial Innovations and Invesco Perpetual. The company raised £200 million on admission to the London Stock Exchange, for a total of £305 million.

Our investment

% share holding

Total funding raised

Carrying value

Imperial College London

Investment stage

Imperial Innovation news

Key milestones

  • 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.

    Read more
  • March 2014

    Circassia admitted to trade on the London Stock Exchange

    Read more
  • October 2013

    Grass allergy treatment achieves significant system reduction during Hay Fever season

    Read more
  • September 2013

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

    Read more
  • February 2013

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

    Read more
  • December 2012

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

    Read more
  • October 2012

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

    Read more
  • 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

    Read more

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