News Release

Immunization instead of medication to control blood pressure

Peer-Reviewed Publication

The Lancet_DELETED

Immunisation against angiotensin* II could lower the blood pressure of patients with high blood pressure (hypertension) and improve treatment adherence, and eventually replace traditional medications for treatment of this common and sometimes life-threatening condition. These are the conclusions of authors of an Article in this week's edition of The Lancet.

Treatment of hypertension with both angiotensin-converting enzyme inhibitors and angiotensin II type I receptor blockers has proven very successful. However, in addition to inadequate diagnosis and prescription, adherence to this treatment is a significant problem -- with only about a third of patients with hypertension in the USA estimated to have their blood pressure under control. Key factors affecting patients' adherence are side-effects and concerns over taking long-term medication in the absence of symptoms. Active immunisation to induce antibodies against angiotensin could simplify treatment -- with an ideal regimen of a few injections per year. Previous attempts to treat hypertension by immunotherapy targeted angiotensin I; however a phase II clinical trial in patients with hypertension showed no reduction in blood pressure. In this Article, the authors target angiotensin II.

Dr Martin Bachmann, Cytos Biotechnology, Schlieren, Switzerland, and colleagues did a phase IIa trial of 72 patients with mild-to-moderate hypertension. The patients were randomly assigned to one of three treatments: subcutaneous injections of 100μg of the vaccine (CYT006-AngQb) (24 patients); 300μg of the vaccine (24 patients); or placebo (24 patients); each at weeks 0, 4, and 12. Ambulatory blood pressure (ie, measurement over 24 hours) was determined before treatment and at week 14. The primary outcomes of the trial were safety and tolerability of the vaccine.

The researchers found that in the 300μg group, there was a reduction from baseline in mean daytime blood pressure at week 14 by -9.0/-4.0 mm Hg compared with placebo. The 300μg dose reduced the early morning blood-pressure surge compared with placebo (change at 0800h: -25/-13 mm Hg). Five serious adverse events were reported across the three groups, but none were deemed to be treatment related. Most side-effects were mild, transient reactions at the injection site. Mild, transient influenza-like symptoms were seen in three patients in the 100μg group and seven in the 300μg group, which the authors say are indicative of a systemic response and are associated with the administration of several vaccines.

The authors say: "The drop in blood pressure was especially pronounced in the early morning, when the renin-angiotensin-aldosterone system is most active and when most cardiovascular events occur."

They say that the life-span (half-life) of antibodies induced by the vaccine is about four months after the third injection. They conclude: "Importantly, it is compatible with a treatment regimen of a few injections per year, when the vaccine could be administered during regular control visits of hypertensive patients to their doctors. Such a regimen is likely to promote adherence to treatment, but will need to be supported by clinical data."

In an accompanying Comment, Dr Ola Samuelsson and Dr Han Herlitz, Department of Nephrology, Sahgrenska University Hospital, Gothenberg, Sweden, say: "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."

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Notes to editors: *Angiotensin is a protein hormone in the blood that causes blood vessels to constrict and increases blood pressure

Dr Martin Bachmann, Cytos Biotechnology, Schlieren, Switzerland T) +41 79 291 85 30 E) martin.bachmann@cytos.com

Dr Ola Samuelsson, Department of Nephrology, Sahgrenska University Hospital, Gothenberg, Sweden T) +46 730 369 407 E) ola.samuelsson@vgregion.se

PDF OF ARTICLE: http://multimedia.thelancet.com/pdf/press/Bloodpressure.pdf


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