CYT006-AngQb was an investigational
vaccine
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified.[ ...]
against
angiotensin II
Angiotensin is a peptide hormone that causes vasoconstriction and an increase in blood pressure. It is part of the renin–angiotensin system, which regulates blood pressure. Angiotensin also stimulates the release of aldosterone from the adr ...
, designed to lower
blood pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressur ...
. It was somewhat effective in
clinical trial
Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...
s, but less so than conventional drugs against
hypertension (elevated blood pressure).
Method of action
Angiotensin II causes blood vessels to constrict, and drives blood pressure up. CYT006-AngQb consists of virus-like particles
covalent
A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atom ...
ly coupled to angiotensin II.
Subcutaneous injection
Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion.
A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, co ...
causes the immune system to produce antibodies which reduce angiotensin II blood levels, lowering blood pressure.
Studies
In a 2008
phase IIa study, 72 patients received 100 µg, 300 µg or placebo in weeks 0, 4, and 12. Blood pressure was lowered dose-dependently, by 5.6 mmHg (systolic) and 2.8 mmHg (diastolic) in the 300 µg group. Morning blood pressure (5:00-8:00) was lowered by 25 mmHg (systolic) and 13 mmHg (diastolic).
Side effects were mild and included local reactions, headache and fatigue.
The 2008 trial was small and exploratory. It did not address the question of whether the vaccine actually protects internal organs, nor did it address safety concerns such as whether the vaccine would cause autoimmune disease. If a standard drug treatment is found to dangerously inhibit the renin-angiotensin-aldosterone system, it can be withdrawn and the effects reversed quickly, but that would not be true of the vaccine. However, poor compliance to standard treatment is the main reason for inadequate control of blood pressure, and if vaccination were safe and effective in the long run, it may solve many compliance problems.
CYT006-AngQb did not reach Phase III studies because the antihypertensive effects were small compared to existing
ACE inhibitor
Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. They work by causing relaxation of blood vessels as well as a decrease in blood volum ...
s and
angiotensin II receptor antagonists, and they were not reproducible across dosing schemes. Similar vaccines with modified
immunogens and different
adjuvant In pharmacology, an adjuvant is a drug or other substance, or a combination of substances, that is used to increase the efficacy or potency of certain drugs. Specifically, the term can refer to:
* Adjuvant therapy
Adjuvant therapy, also known ...
s are being investigated.
References
{{DEFAULTSORT:Cyt006angqb
Vaccines
Antihypertensive agents