Kuros Biosciences Ltd.

Regulatory Filings • Jun 24, 2009

News Details

Corporate | 24 June 2009 18:00

Cytos Biotechnology reports biochemical findings from phase IIa study with hypertension vaccine CYT006-AngQb

Cytos Biotechnology AG / Research Update

Release of a Corporate News, transmitted by DGAP - a company of EquityStory
AG.
The issuer / publisher is solely responsible for the content of this announcement.

---

Schlieren (Zurich), Switzerland, June 24, 2009 - Cytos Biotechnology Ltd
(SIX:CYTN) announced today results from a biochemical analysis from a phase
IIa study (study 02) with the vaccine candidate CYT006-AngQb for the
treatment of hypertension. CYT006-AngQb has demonstrated in a first phase
IIa study (study 01) a significant reduction of the day-time ambulatory
blood pressure of -9 / -4 mmHg (systolic/diastolic) vs. placebo (The Lancet
2008, 371:821). In study 02 an accelerated treatment regimen with
injections at weeks 0, 2, 4, 6, and 10 was tested, while in study 01 the
vaccine was given at weeks 0, 4, and 12. This modification was anticipated
to induce higher antibody titers and, thereby, a stronger blood pressure
reduction. While first study results which were communicated on March 17,
2009 showed on average a 5-fold higher antibody titer in study 02 than in
study 01, the blood pressure reductions in study 02 were much lower than in
study 01; they amounted to -2.3 / -0.4 mmHg. In order to understand this
discrepancy, the biochemical properties of the induced antibody responses
were analyzed in detail. The main findings are as follows:

• Antibody affinities (i.e. the strength by which the antibodies bind
  angiotensin II) determined by different biochemical methods were
  significantly lower in study 02 than in study 01 (p<0.001).

• The amount of angiotensin II sequestered in the blood of vaccinated
  individuals was on average 33% lower in study 02 than in study 01.

• The individual changes in daytime ambulatory blood pressure correlated
  with the individual antibody affinities (p=0.10) and, in particular,
  with measures for the off-rates, describing how long angiotensin II is
  bound to the antibodies (p=0.006). This means that patients whose
  antibodies had a higher affinity and which bound angiotensin II for a
  longer period of time showed a larger blood pressure reduction. No such
  correlation was detected between individual antibody titers and blood
  pressure reductions (p=0.47).

A hypothesis which would be compatible with the above findings is that an
accelerated treatment regimen like in study 02 leads to the induction of
antibody responses with higher titers but lower affinities, thereby
creating a lower capacity for sequestering angiotensin II in the blood, and
ultimately leading to a smaller blood pressure reduction. Cytos
Biotechnology will prospectively test this hypothesis in study 03 which is
currently ongoing and which will be un-blinded in Q3, 2009. Study 03 uses
the same treatment regimen as study 02, but higher doses of the vaccine.

Understanding of how the treatment parameters dose and regimen are
affecting pharmacodynamic responses like antibody titers, affinities and
effects on blood pressure is crucial for the development of a novel therapy
like CYT006-AngQb. A positive validation of the above hypothesis in study
03 would therefore guide the next development step of this vaccine
candidate which would then focus on the induction and subsequent boosting
of high affinity antibodies.

About the hypertension vaccine CYT006-AngQb

CYT006-AngQb is a therapeutic vaccine in development for the treatment of
hypertension (1, 2). It is designed to instruct the patient's immune system
to produce an antibody response against angiotensin II. Angiotensin II is a
small peptide in the body and part of the renin-angiotensin system (RAS),
which is an important regulator of blood pressure. Angiotensin II causes
blood vessels to narrow, resulting in increased blood pressure. In a phase
IIa study with hypertensive patients, vaccination with CYT006-AngQb has
been shown to significantly reduce the mean ambulatory day-time blood
pressure by induction of antibodies that bind angiotensin II (The Lancet
2008, 371:821). A particularly strong blood pressure reduction has been
observed in the early morning hours - a crucial time of day when adverse
cardiovascular events are more likely to occur than during other times of
the day.

CYT006-AngQb is a first-in-class product candidate in this important
indication and represents a completely novel approach to hypertension
treatment. Treatment with CYT006-AngQb should allow for convenient dosing
schedules and a smooth control of blood pressure due to a sustained
antibody response induced by vaccination.

About hypertension

Hypertension, also termed high blood pressure, is a medical condition where
the blood pressure is chronically elevated. Although symptomless in nature
and in itself rarely an acute problem, persistent hypertension is one of
the most important preventable causes of premature death worldwide and
contributes to around half of all cardiovascular diseases (3). It is one of
the major risk factors for stroke, myocardial infarction, heart failure,
and vascular disease, and is a leading cause of chronic renal failure.
Genetic predisposition and lifestyle habits such as inadequate physical
activity, high fat diet, and high salt intake promote high blood pressure.
Up to 30% of adults in most countries suffer from hypertension. Despite
effective and relatively inexpensive treatment available, less than one out
of four hypertensive individuals have their blood pressure controlled
successfully (4,5). This poor overall treatment success is mainly
attributed to the symptomless nature of hypertension and the necessity for
long-term treatment with currently available medications that require at
least once daily self-administration.

Glossary

Affinity: A measure which describes how strong an antibody binds to its
target molecule.

Ambulatory blood pressure: Blood pressure measured by numerous readings
over a 24-hour period or longer. Provides accurate and reliable information
about a person's blood pressure.

Angiotensin II: A small peptide that is part of the renin-angiotensin
system (RAS). Induces narrowing of blood vessels and other effects to raise
blood pressure.

Antibody: Class of blood proteins generated by the immune system to
neutralize foreign materials such as bacteria or viruses. Can also be
directed against the body's own disease-associated molecules.

Diastolic blood pressure: Lowest pressure within the arterial blood stream
occurring with each heart beat.

Off-Rate: Describes the rate at which an antibody-target complex
dissociates.

Systolic blood pressure: The highest pressure within the arterial blood
stream occurring with each heart beat.

Titer: A relative measure for the amount of antibodies that bind to a
target molecule.

References

(1) Journal of Hypertension; A vaccine for hypertension based on virus-like
particles: preclinical efficacy and phase I safety and immunogenicity;
2007, 25:63

(2) The Lancet; Effect of immunization against angiotensin II with
CYT006-AngQb on ambulatory blood pressure: a double-blind, randomized,
placebo-controlled phase IIa study; 2008, 371:821

(3) Centres for Disease Control and Prevention (CDC); The Atlas of Heart
Disease and Stroke, 2004

(4) Journal of the American Medical Association (JAMA); The Seventh Report
of the Joint National Committee on Prevention, Detection, Evaluation, and
Treatment of High Blood Pressure; 2003, 289:2560

(5) National Institute for Health and Clinical Excellence (NICE), Centre
for Health Services Research, UK; Essential Hypertension: managing adult
patients in primary care; August 2004

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 Immunodrugs(TM). Immunodrugs(TM)
are
intended for use in the treatment and prevention of common chronic
diseases, which afflict millions of people worldwide. Immunodrugs(TM) 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 Immunodrug(TM)
platform, Cytos Biotechnology has built a diversified pipeline of different
Immunodrug(TM) candidates in various disease areas, of which six are
currently
in clinical development. The Immunodrug(TM) candidates are developed both
in-house and together with Novartis, Pfizer, and Pfizer Animal Health.
Founded in 1995 as a spinoff from the Swiss Federal Institute of Technology
(ETH) in Zurich, the company is located in Schlieren (Zurich). Cytos
Biotechnology Ltd is listed on the SIX Swiss Exchange (SIX:CYTN).

This foregoing press release may contain forward-looking statements that
include words or phrases such as 'may', 'will', 'would', 'can', 'could',
'anticipate', 'designed', 'intend' or other similar expressions. These
forward-looking statements are subject to a variety of significant
uncertainties, including scientific, business, economic and financial
factors, and therefore actual results may differ significantly from those
presented. There can be no assurance that any further therapeutic entities
will enter clinical trials, that clinical trial results will be predictive
for future results, that therapeutic entities will be the subject of
filings for regulatory approval, that any drug candidates will receive
marketing approval from the U.S. Food and Drug Administration or equivalent
regulatory authorities, or that drugs will be marketed successfully.
Against the background of these uncertainties readers should not rely on
forward-looking statements. The company assumes no responsibility to update
forward-looking statements or adapt them to future events or developments.
This document does not constitute an offer or invitation to subscribe or
purchase any securities of Cytos Biotechnology Ltd.

Wolfgang A. Renner, PhD
Chief Executive Officer
Cytos Biotechnology Ltd
Phone: +41 44 733 47 03
Fax: +41 44 733 47 04
e-Mail: wolfgang.renner@cytos.com
Website: www.cytos.com
24.06.2009 Financial News transmitted by DGAP

---

Language: English
Issuer: Cytos Biotechnology AG
Wagistr. 25
8952 Schlieren
Schweiz
Phone: +41 44 733 4747
Fax: +41 44 733 4740
E-mail: info@cytos.com
Internet: www.cytos.com
ISIN: CH0011025217, CH0029060735
WKN: -
Listed: Freiverkehr in Berlin, München, Stuttgart; Open Market in
Frankfurt; Foreign Exchange(s) SWX

End of News DGAP News-Service

---