FDA modifies boxed warning for pulmonary arterial hypertension drug Letairis

The U.S. Food and Drug Administration today (March 4) announced that monthly liver enzyme tests are no longer required for those taking Letairis tablets (ambrisentan), used to treat high blood pressure in the vessels that carry blood to the lungs (pulmonary arterial hypertension, or PAH).

Citing data from clinical trials and postmarket reports, the FDA said that the drug poses only a low risk of liver injury. Information related to potential serious liver injury and the need to monitor for such serious injury is being removed from the drug’s boxed warning.

In patients with PAH, Letairis slows the worsening of symptoms and improves the ability to exercise. Approved in 2007, Letairis is in a class of medications called endothelin receptor antagonists, which stop the action of endothelin, a substance that narrows blood vessels and prevents normal blood flow in those with PAH.

“We have concluded that monthly liver enzyme testing for patients taking Letairis, as previously noted in the boxed warning, is not necessary,” said Mary Ross Southworth, Pharm.D., deputy director for safety in the Division of Cardiovascular and Renal Products at the FDA’s Center for Drug Evaluation and Research. “Health care professionals should still continue to order liver enzyme tests when they consider it clinically indicated.”

Letairis was approved with a Risk Minimization Action Plan (RiskMAP) to manage liver damage and fetal malformation. The RiskMAP called for liver enzyme testing prior to treatment and monthly during treatment for all patients. It also required monthly pregnancy testing for women of childbearing potential because Letairis causes birth defects in animals, like other drugs in this class. The Letairis RiskMAP was converted to a Risk Evaluation and Mitigation Strategy in 2009.

The boxed warning on the risk of serious birth defects and the contraindication for use during pregnancy will remain in the labeling. Letairis will continue to be available only through a restricted distribution program called the Letairis Education and Access Program (LEAP). For women who can become pregnant, monthly pregnancy tests will still be required before Letairis is shipped.

The liver warnings were based on experience with other drugs in Letairis’ drug class, as well as a few observed instances of increased liver enzymes in people treated with Letairis. The FDA’s further evaluation has shown that rates of liver problems in Letairis-treated patients are consistent with rates within the general PAH population. In the controlled clinical trials, the rates of liver problems in Letairis-treated patients are similar to the rates in people receiving an inactive pill (placebo).

For a discussion of the FDA’s rationale and regulatory decisions regarding Letairis, refer to the Drug Safety Communication issued today.

People who take Letairis should not stop taking it without talking to their health care professional. Health care professionals should order and review tests for liver function as necessary based on the patient’s condition and history. Adverse events involving Letairis should be reported to the FDA MedWatch program1.

Letairis is made by Gilead Sciences Inc., Foster City, Calif.

-----
Community News You Can Use
Click to read MORE news:
www.GeorgiaFrontPage.com
Twitter: @gafrontpage & @TheGATable @HookedonHistory
www.ArtsAcrossGeorgia.com
Twitter: @artsacrossga, @softnblue, @RimbomboAAG @FayetteFP

FDA Approves EDARBI (azilsartan medoxomil) for the Treatment of Hypertension

/PRNewswire/ -- Takeda Pharmaceutical Company Limited (Takeda) and its wholly-owned subsidiary, Takeda Pharmaceuticals North America, Inc., today announced that the U.S. Food and Drug Administration (FDA) approved EDARBI (azilsartan medoxomil) for the treatment of hypertension, or high blood pressure, in adults. EDARBI is an angiotensin II receptor blocker (ARB) that lowers blood pressure by blocking the action of angiotensin II, a vasopressor hormone that constricts blood vessels. When the angiotensin II receptor is blocked, blood vessels stay relaxed and open and blood pressure can be reduced. EDARBI is approved as a once-daily oral therapy for use alone and for use in combination with other antihypertensive medications.

Takeda Global Research & Development Center, Inc. U.S. submitted a new drug application (NDA) for EDARBI in April 2010. The NDA was supported by seven controlled phase 3 clinical trials involving more than 5,900 patients with hypertension. Pivotal phase 3 studies showed EDARBI (80 mg/day) was statistically superior to placebo and the highest approved doses of two commonly prescribed ARBs, olmesartan medoxomil (40 mg/day) and valsartan (320 mg/day), in lowering both clinic and 24-hour mean blood pressure measurements.

"We are pleased to be able to build upon our global expertise in the cardiovascular therapeutic area with the approval of EDARBI in the U.S.," said Shinji Honda, president and CEO, Takeda Pharmaceuticals North America. "Through the discovery, development and commercialization of new medicines, Takeda is committed to bringing therapies like EDARBI to market. EDARBI is an important new treatment option for patients with hypertension and the health care professionals who treat them."

The safety and efficacy of EDARBI were studied as a once-daily oral therapy, as well as in combination with chlorthalidone and amlodipine. Results from the phase 3 clinical trials showed EDARBI successfully met the primary endpoint, change in 24-hour mean systolic blood pressure (SBP) as measured by Ambulatory Blood Pressure Monitoring, with statistical significance of lowering blood pressure compared to placebo and head-to-head active comparators. Specifically, results from one study showed EDARBI at doses of 80 mg/day and 40 mg/day lowered 24-hour mean SBP by 14.3 mm Hg and 13.2 mm Hg from baseline, respectively. The blood pressure reductions of EDARBI (80 mg/day) were statistically superior to those of the active comparators valsartan 320 mg/day (-10.0 mm Hg) and olmesartan medoxomil 40 mg/day (-11.7 mm Hg). Similar results were observed in all three comparator studies. The most common adverse reaction in adults was diarrhea (2%).

About Hypertension

Hypertension, or high blood pressure, is a chronic medical condition in which blood pressure is elevated at levels of 140 mm Hg or greater systolic or 90 mm Hg or greater diastolic. Hypertension impacts approximately 75 million Americans, or nearly one in three adults. It is estimated that nearly one billion people are affected by hypertension worldwide, and this figure is predicted to increase to 1.5 billion by 2025. Hypertension typically has no symptoms. Adults of all ages and backgrounds can develop hypertension; however, the risk of developing the condition increases with age, with more than half of people over age 60 affected. Hypertension is also costly to the nation's health care system. The American Heart Association recently estimated that direct and indirect expenses associated with hypertension cost the nation more than $73 billion in 2009.

-----
Community News You Can Use
Click to read MORE news:
www.GeorgiaFrontPage.com
Twitter: @gafrontpage & @TheGATable @HookedonHistory
www.ArtsAcrossGeorgia.com
Twitter: @artsacrossga, @softnblue, @RimbomboAAG @FayetteFP

Researchers Discover Hydrogen Sulfide Is a Major Regulator of Blood Pressure

Anyone with a nose knows the rotten-egg odor of hydrogen sulfide, a gas generated by bacteria living in the human colon. Now an international team of scientists has discovered that cells inside the blood vessels of mice — as well as in people, no doubt — naturally make the gassy stuff, and that it controls blood pressure.

Having discovered that hydrogen sulfide, or H2S, is produced in the thin, endothelial lining of blood vessels, the researchers, including scientists from Johns Hopkins, report today in Science that H2S regulates blood pressure by relaxing blood vessels. As the newest member of a family of so-called gasotransmitters, this messenger molecule is akin in function, if not form, to chemical signals like nitric oxide, dopamine and acetylcholine that relay signals between nerve cells and excite or put the brakes on mind-brain activities.

“Now that we know hydrogen sulfide’s role in regulating blood pressure, it may be possible to design drug therapies that enhance its formation as an alternative to the current methods of treatment for hypertension,” says Johns Hopkins neuroscientist Solomon H. Snyder, M.D., a co-author of the paper.

Conducting their investigations using mice missing a gene for an enzyme known as CSE, long suspected as responsible for making H2S, the researchers first measured hydrogen sulfide levels in a variety of tissues in the CSE-deficient mice and compared them to normal mice. They found that the gas was largely depleted in the cardiovascular systems of the altered mice, engineered by Rui Wang, M.D., Ph.D., of Lakehead University in Ontario, and Lingyun Wu, M.D., Ph.D., of the University of Saskatchewan, Canada. By contrast, normal mice had higher levels — clear evidence that hydrogen sulfide is normally made by mammalian tissues using CSE.

Next, the scientists applied tiny cuffs to the tails of the mice and measured their blood pressure, noting spikes of about 20 percent, comparable to serious hypertension in humans.

Finally, the team tested how blood vessels of CSE-deficient mice responded to the chemical neurotransmitter methacholine, known to relax normal blood vessels. The blood vessels of the altered mice relaxed hardly at all, indicating that hydrogen sulfide was largely responsible for relaxation.

Because gasotransmitters are highly conserved in mammals, the findings of the research are believed to have broad applications to human physiology and disease.

“In terms of relaxing blood vessels, it looks like hydrogen sulfide might be as important as nitric oxide,” Snyder says, referring to the first gasotransmitter that two decades ago was discovered to regulate blood pressure.

Just because these two gas molecules perform similar functions, doesn’t mean they’re redundant, says Wang, the paper’s principal author. “Nature has added on layer upon layer of complexity to provide a better and tighter control of body function — in this case, of blood pressure.”

Studying gaseous messengers can be tricky, explains Snyder, an authority on nitric oxide (NO) whose lab in 1990 discovered that the enzyme triggering NO production is activated by a protein mechanism known as calcium-calmodulin.

“When a nerve fires, it releases a bit of neurotransmitter. Then it fires again, very quickly, and releases more of the neurotransmitter, which is always in reserve and at the ready in large storage pools called vesicles. However, gasses can’t be stored; they diffuse. So every time there’s a nerve impulse, an enzyme must be activated to make it,” he says.”

Although CSE, the enzyme that activates hydrogen sulfide, was characterized more than half a century ago, the new work is the first to reveal that it is activated in the same way as the nitric oxide-forming enzyme, thus establishing how hydrogen sulfide regulates blood pressure by relaxing blood vessels.

“It’s difficult to overestimate the biological importance of hydrogen sulfide or its implications in hypertension as well as diabetes and neurodegenerative diseases,” Wang says. “In fact, most human diseases probably have something to do with gasotransmitters.”

The research was supported by grants from the U.S. Public Health Service and the Canadian Institutes of Health Research as well as a Research Scientist Award.

Authors on the paper are Guangdong Yang, Lingyun Wu, Bo Jiang, Wei Yang, Jiansong Qi, Kun Cao, Qinghe Meng, all of the University of Saskatchewan, Canada; Wang of the University of Saskatchewan and Lakehead University, Canada; Shengming Zhang of Lakehead University, Canada; and Asif K. Mustafa, Weitong Mu and Snyder, all of Hopkins.

-----
www.fayettefrontpage.com
Fayette Front Page
www.georgiafrontpage.com
Georgia Front Page

Poor Perioperative Blood Pressure Control Linked to 30-Day Morbidity and Mortality in Cardiac Surgery Patients

Business Wire - The Medicines Company (NASDAQ: MDCO) announced October 21, 2008, that poor blood pressure control during cardiac surgery is associated with a higher risk of 30-day death, stroke, myocardial infarction and renal dysfunction, compared to patients with tight blood pressure control, according to a post-hoc analysis of the ECLIPSE trial. The data were presented at the American Society of Anesthesiologists (ASA) 2008 Annual Meeting.

“In this analysis, what we found was clear: the worse the blood pressure control, the poorer the outcome in these cardiac surgery patients,” said Solomon Aronson, M.D., Professor of Anesthesiology, Duke University School of Medicine. “These data support the need to more effectively manage blood pressure in the surgical and critical care settings.”

The ECLIPSE trial enrolled 1,964 cardiac surgery patients in one of three randomized, open-label trials comparing Cleviprex™ (clevidipine butyrate) injectable emulsion to nitroglycerin, sodium nitroprusside or nicardipine. In this post-hoc analysis, 1507 ECLIPSE patients were stratified by precision of blood pressure control measured as excursions and time out of a pre-specified range. Adverse outcomes, assessed as death, myocardial infarction, stroke and renal dysfunction at 30 days post-discharge, were significantly higher in patients with poor blood pressure control (14.4%) than in patients with tight blood pressure control (8.8%).

“These critical new findings underscore the risk posed by uncontrolled blood pressure during cardiac surgery and emphasize the need for tight blood pressure control in these patients,” said James Ferguson, M.D., Vice President, Global Medical, Surgical and Critical Care, The Medicines Company. “Cleviprex, recently approved by the FDA, provides physicians with an important, new clinical tool for achieving rapid and predictable blood pressure control.”

Additional post-hoc data from the pivotal ECLIPSE program, involving patients undergoing cardiac valve surgery, will be presented at the American College of Chest Physicians (ACCP) annual meeting in Philadelphia on Tuesday, October 28, 2008.

-----

www.fayettefrontpage.com
Fayette Front Page
www.georgiafrontpage.com
Georgia Front Page