Vaccination for Hypertension
In most challenging era of Hypertension Management, various multiple drug regimens are used to control the Blood Pressure. But the most burdensome is the difficulties in adhering to antihypertensive medication regimens.
Good control of hypertension has been undermined by problems of patient compliance with antihypertensive medications. Although many effective drugs are available, only about 25% of patients are optimally controlled, Dr. Nussberger said. "This has probably something to do with the fact that these drugs have to be taken daily and lifelong."
However, many of these drugs have a half-life of less than 24 hours, so if patients take them in the morning, the medications are at a trough in the early-morning hours, he said, just as the normal rise in blood pressure takes place and when most cardiovascular events occur.
There is significant potential for this kind of approach to treating hypertension.
Immunization against angiotensin II:
"In order to develop a vaccine that can reduce hypertension, it must be able to trigger a highly specific immune response. The blood pressuring- increasing angiotensin II and the blood pressure-reducing angiotensin 1-7 differ by only one amino acid, while the remainder of the structure is identical.
The vaccine spurs the body to make antibodies that target a protein called angiotensin II, which helps constrict blood vessels. By sidelining angiotensin II, blood vessels stay more relaxed, keeping blood pressure lower.
There are drugs that act on angiotensin II. But some high blood pressure patients don't take their medicines as instructed, hence the interest in a blood pressure vaccine.
Immunization against angiotensin II may offer a valuable alternative to conventional drugs for the treatment of hypertension, because vaccines induce relatively long-lasting effects and do not require daily dosing. Here we describe the preclinical development and the phase I clinical trial testing of a virus-like particle (VLP)-based antihypertensive vaccine.
7 vaccines under pipeline:
In China, researchers are focusing on a target further along the RAS system, and they have developed a virus-like particle (VLP)-based antihypertensive vaccine, ATR12181, that utilizes a peptide from the extracellular portion of rat angiotensin II type 1A (AT1A) receptor. The research is funded by the National Natural Science Foundation of China.
The vaccine was previously shown to be effective in reducing blood pressure and ameliorating remodeling of target organs in spontaneously hypertensive rats (SHR) at 5 months.The long-term, 64-week study was carried out in 12 male, 6-week-old SHRs. One group of 6 animals was immunized against the peptide from rat AT1A receptor by repeated subcutaneous injections of ATR12181, whereas 6 control animals received 0.9% saline. The schedule for administration in each group was 0, 4, 9, 12, 16, 24, 32, 40, and 52 weeks.
ATR12181 significantly reduced LV fibrosis and, in the kidneys, glomerular damage and interstitial fibrosis were significantly attenuated in the vaccine group compared with the control group.
The current study explored the safety and tolerability of CYT006-AngQb, a virus like particle-based conjugate vaccine that targets angiotensin II in a placebo-controlled phase 2a sequential 2-dose comparison trial. In the study, 72 patients with mild to moderate hypertension, defined as a systolic pressure of 140 to 179 mm Hg and a diastolic pressure of 90 to 109 mm Hg, were enrolled; 5 patients dropped out for reasons unrelated to the study, he noted.
The study was done over 4 months; patients were given 100 µg or 300 µg of the antigen or placebo at time zero, then at 1 month and 3 months, after which they were followed for 8 months for safety. End points were safety and tolerability, with an "exploratory" look at efficacy with ambulatory blood pressure measurements and plasma rennin concentrations.
And few other bio-pharma is developing such vaccines for hypertension.
Adverse Events:
No serious side effects were linked to the vaccine. Adverse events were generally mild and included injection site reactions and flu-like symptoms and they are pain, erythema, or edema at the injection site. Headache was also more frequent in the vaccination group, but all of these effects occurred over the first 1 or 2 days and were reversible. Several studies to investigate further the safety and efficacy of the vaccine are now being planned, Dr. Nussberger
Conclusion:
Dr. Liao and his colleagues believe that targeting the AT1 receptor with a vaccine may provide the basis for an immunologic approach to the treatment of hypertension and its associated cardiovascular and renal risk factors. Further studies are needed to determine the mechanism by which VLP vaccine lowers blood pressure.
Nevertheless, the results of this new biotherapy for hypertension are intriguing and promising, and vaccination for hypertension may turn out to be very useful in many patients," If the vaccine fares well in those tests, patients would need "a few injections per year" and hypertension management will become very amicable.
by
N.Shanmuga Priya.
Sounds interesting.
Priya.N