Cytos Biotechnology Ltd (SWX:CYTN) announced results from two randomized, double-blind, placebo-controlled, multicentre phase II studies with CYT003-QbG10 monotherapy for the treatment of house dust mite and cat allergy, and with CYT005-AllQbG10 combination therapy for the treatment of house dust mite allergy. The studies were conducted in order to determine whether QbG10 acts through an allergen-independent or allergendependent mechanism of action and to define the strategy for late-stage development of this product candidate.

Study 08 with CYT003-QbG10 monotherapy included 80 patients suffering from house dust mite and / or cat allergy and investigated the safety, tolerability and efficacy of six injections of ascending doses of CYT003-QbG10 (300-900?g) or placebo. Treatment with CYT003-QbG10 was safe, very well tolerated and significantly reduced rhinoconjunctivitis symptoms in daily life compared to placebo (p=0.008). The CYT003-QbG10 treatment group mean total rhinoconjunctivitis symptom score had fallen from 9.3 points pre-treatment to 3.6 points post-treatment (-61%), whereas for the placebo group a reduction from 9.2 points pre-treatment to 6.3 points post-treatment (-32%) was observed.

Also, the allergen tolerance as measured in the conjunctival provocation test was improved after CYT003-QbG10 treatment compared to placebo (borderline significant, p=0.06).

In study 04, which compared CYT005-AllQbG10 (i.e. the combination of 300?g QbG10 with an approved allergen extract) and the allergen extract alone in 93 patients suffering from house dust mite allergy, reductions of the mean total rhinoconjunctivitis symptom score of -54% for CYT005- AllQbG10 and -51% for the allergen extract were observed (not significant).

The conjunctival provocation test showed a trend in favour of CYT005-AllQbG10 (p=0.11). The total number of suspected adverse events was similar in both treatment arms and was attributed mainly to the presence of the allergen extract (CYT005-AllQbG10: 219 events; approved allergen extract alone: 209 events). In contrast to this, CYT003-QbG10 monotherapy in study 08 was much better tolerated with a total number of suspected adverse events of only 20 (placebo: 10).

Dr. Wolfgang Renner, CEO of Cytos Biotechnology commented: "The two studies clearly answered our primary question about the mechanism of action of QbG10. To our great satisfaction it turned out that QbG10 is active as a monotherapy and that addition of an allergen extract is not necessary. On the contrary, avoidance of allergen extracts dramatically improves tolerability as we have seen in study 08. A product with an allergen-independent mechanism of action has major advantages over current immunotherapy approaches, which are all based on allergen components. By nature, allergen extracts can cause severe side effects, which may lead to potentially life-threatening conditions like anaphylaxis. This is why these treatments are contraindicated in those patients who would benefit most from them: People with severe allergies and asthma. In addition, such treatments are usually administered only by specially trained physicians.

In contrast to this, the almost placebo-like side effect profile of CYT003-QbG10 monotherapy may enable the use of this product in larger patient populations and by general practitioners. Its allergen-independent mechanism of action simplifies treatment, since a single agent can be used for the treatment of multiple allergies. Also, it may be possible to use this product in people for whom immunotherapy is currently contraindicated.

With these major advantages, CYT003-QbG10 has potential to rejuvenate the mature allergic diseases market, which is dominated by either purely symptomatic drugs like antihistamines or corticosteroids or by immunotherapy products containing allergen components. We are therefore excited to advance CYT003-QbG10 monotherapy as a first-in-class, disease-modifying product candidate into late-stage development. Start of phase IIb is planned already in the forth quarter this year."

About CYT003-QbG10 / CYT005-AllQbG10

CYT003-QbG10 / CYT005-AllQbG10 are immunotherapeutic products in development for the treatment of allergy and asthma. Both are based on Cytos Biotechnology's second ImmunodrugT platform, which applies immunostimulatory DNA sequences to induce targeted T cell responses. The immunotherapeutics encompass the virus-like particle Qb, which has been filled with the immunostimulatory DNA sequence G10 - a synthetically produced stretch of DNA originally derived from bacteria. The resulting entity QbG10 is designed as a disease-modifying treatment and aims to alter the immunological milieu and the allergic immune cell responses to ameliorate disease symptoms. CYT003-QbG10 represents QbG10 monotherapy, whereas CYT005-AllQbG10 consists of QbG10 combined to an approved allergen extract of house dust mites. As clinical observations of the present as well as earlier studies indicate, CYT003-QbG10 monotherapy seems to act by an allergenindependent mechanism of action so that it has potential as a treatment for a broad range of different allergies.

About allergic diseases

Allergy as a whole is a multi-faceted disease and manifests itself clinically in various allergic disorders including allergic rhinoconjunctivitis, asthma, eczema and food hypersensitivity. It is an exaggerated reaction by the patient's immune system to a normally harmless substance such as various environmental proteins present in pollen, dust mite faeces, or food. Allergy is a very common chronic disease, and its prevalence has increased dramatically within the last few decades. Today, more than 20% of the world population suffers from allergic diseases1, and Europe alone has 80 million adult allergy sufferers2. House dust mites and cats represent the two most important allergen sources for perennial allergies.

There are three general approaches being pursued today to relieve the symptoms of allergic diseases: avoidance of the allergen whenever possible; prescription of medication that targets disease symptoms; and conventional immunotherapy, also known as desensitization. Symptomatic medication available only offers short-term amelioration of the disease. For patients this may mean chronic use of corticosteroids and antihistamines - often with multiple daily doses. Conventional immunotherapy, on the other hand, is very time-consuming (3-5 years) and, with up to 80 allergen injections, it is also inconvenient for the patient, so that only few allergy sufferers take advantage of this therapy. It is, however, the only curative treatment available for some defined allergies and reduces disease symptoms over a longer period of time. There remains significant unmet medical need for disease-modifying and convenient allergy treatments.

About Cytos Biotechnology

Cytos Biotechnology Ltd is a public Swiss biotechnology company that specializes in the discovery, development and commercialization of a new class of biopharmaceutical products - the ImmunodrugsT. ImmunodrugsT are intended for use in the treatment and prevention of common chronic diseases, which afflict millions of people worldwide. ImmunodrugsT are designed to instruct the patient's immune system to produce desired therapeutic antibody or T cell responses that modulate chronic disease processes. Taking advantage of the high flexibility of its ImmunodrugT platform, Cytos Biotechnology has built a diversified pipeline of different ImmunodrugT candidates in various disease areas, of which 6 are currently in clinical development. The ImmunodrugT candidates are developed both in-house and together with Novartis and Pfizer Animal Health. Founded in 1995 as a spin-off from the Swiss Federal Institute of Technology (ETH) in Zurich, the company is located in Schlieren (Zurich). Currently, the company has 132 employees. Cytos Biotechnology Ltd has been listed on the SWX Swiss Exchange (SWX:CYTN) since October 2002.


1 World Health Organization; Prevention of Allergy and Allergic Asthma, January 2002.

2 GAL2EN - Global Allergy and Asthma European Network,, 2008.


-- Allergen: a normally harmless substance that elicits a misdirected immune response.

-- Allergen extract: a mixture of allergenic components from e.g. house dust mites.

-- Allergen tolerance: non-reactivity to a certain allergen or reactivity only up to the level of a predefined symptom score.

-- Anaphylaxis: an acute and potentially life-threatening reaction of the immune system to specific stimuli. If untreated, it can result in shock, respiratory and cardiac failure, and death.

-- Conjunctival provocation test: a commonly used allergy test to monitor the allergic disease status of an individual.

-- Contraindicated: when a medical treatment is not advised for use.

-- Combination therapy: see under monotherapy.

-- Disease-modifying: in contrast to symptomatic treatment, a disease-modifying treatment aims at addressing the cause of disease and modifying the disease progression.

-- Double-blind: a set-up often used in clinical trials where neither the doctor nor the patients know if placebo or the active drug is applied.

-- Immunotherapy / immunotherapeutic: a therapy / a medication aimed at activation of the immune system to modulate a certain disease process.

-- Monotherapy: treatment with one drug as opposed to combination therapy. Here the term refers to treatment with QbG10 alone (i.e. CYT003-QbG10) in contrast to the regimen where QbG10 is combined to allergen extract (i.e. CYT005-AllQbG10).

-- Phase II / phase IIb: clinical trial that examines a new drug candidate's safety, tolerability and efficacy in a larger group of patients.

-- Placebo: dummy medical treatment.

-- QbG10: Cytos Biotechnology's ImmunodrugT Qb filled with the immunostimulatory DNA sequence G10.

Rhinoconjunctivitis: combination of rhinitis (inflammation of the nasal mucosa) and conjunctivitis (inflammation of the eye).

-- T cell: immune cell playing an important role in cell-mediated immunity. One differentiates various subgroups such as cytotoxic (killer) T cells and T helper (Th) cells.

Cytos Biotechnology Ltd