Sacubitril/valsartan

src: heart.bmj.com

Sacubitril/valsartan, sold under the brand name Entresto among others, is a combination drug for use in heart failure developed by Novartis. It consists of the neprilysin inhibitor sacubitril and the angiotensin receptor blocker valsartan, in a 1:1 mixture by molecule count. It is recommended for use as a replacement for an ACE inhibitor or an angiotensin receptor blocker in people with heart failure with reduced ejection fraction.

Side effects include angioedema, kidney problems, and low blood pressure. The risk of kidney problems and increased levels of serum potassium with sacubitril/valsartan is lower than that of an ACE inhibitor or angiotensin receptor blocker. The combination is sometimes described as an "angiotensin receptor-neprilysin inhibitor" (ARNi).

It was approved under the FDA's priority review process on July 7, 2015. It is also approved in Europe. In the USA, the wholesale cost for a year of sacubitril/valsartan is $4,560 per person as of 2015. Similar class generic drugs without sacubitril, such as valsartan alone, cost approximately $48 a year. One analysis found a cost of $45,017 per QALY. The wholesale cost to the National Health Service in the UK is approximately £1,200 per person per year.

Video Sacubitril/valsartan

Medical uses

Sacubitril/valsartan can be used instead of an ACE inhibitor or an angiotensin receptor blocker in people with heart failure and a reduced left ventricular ejection fraction (LVEF), alongside other standard therapies (e.g. beta-blockers) for heart failure. It is not known whether sacubitril/valsartan is useful for the treatment of heart failure in people with normal LVEF. The level of evidence to support its use is less than that for ACE inhibitors and ARBs. In those with class 2 or 3 failure who do well with an ACE inhibitor or ARB but still have symptoms, changing to sacubitril/valsartan decreases the risk of death. It has not been compared directly to ARBs as of 2016.

Changing 100 people from an ACE inhibitor or angiotensin II receptor antagonist to sacubitril/valsartan for 2.3 years would prevent 3 deaths, 5 hospitalizations for heart failure, and 11 hospitalizations overall.

Maps Sacubitril/valsartan

Adverse effects

Common adverse effects in the main study were cough, hyperkalemia (high potassium levels in the blood, which can be caused by valsartan), kidney dysfunction, and hypotension (low blood pressure, a common side effect of vasodilators and ECF volume reducers). 12% of the patients withdrew from the study during the run-in phase because of such events.

Sacubitril/valsartan is contraindicated in pregnancy because it contains valsartan, a known risk for birth defects.

src: heartfailure.onlinejacc.org

Pharmacology

Valsartan blocks the angiotensin II receptor type 1 (AT₁). This receptor is found on both vascular smooth muscle cells, and on the zona glomerulosa cells of the adrenal gland which are responsible for aldosterone secretion. In the absence of AT₁ blockade, angiotensin causes both direct vasoconstriction and adrenal aldosterone secretion, the aldosterone then acting on the distal tubular cells of the kidney to promote sodium reabsorption which expands extracellular fluid (ECF) volume. Blockade of (AT₁) thus causes blood vessel dilation and reduction of ECF volume.

Sacubitril is a prodrug that is activated to sacubitrilat (LBQ657) by de-ethylation via esterases. Sacubitrilat inhibits the enzyme neprilysin, a neutral endopeptidase that degrades vasoactive peptides, including natriuretic peptides, bradykinin, and adrenomedullin. Thus, sacubitril increases the levels of these peptides, causing blood vessel dilation and reduction of ECF volume via sodium excretion.

Neprilysin also has a role in clearing the protein amyloid beta from the cerebrospinal fluid, and its inhibition by sacubitril has shown increased levels of AB_1-38 in healthy subjects (Entresto 194/206 for two weeks). Amyloid beta is considered to contribute to the development of Alzheimer's disease.

src: www.onlinejacc.org

Chemistry

Sacubitril/valsartan is co-crystallized sacubitril and valsartan, in a one-to-one molar ratio. One sacubitril/valsartan complex consists of six sacubitril anions, six valsartan anions, 18 sodium cations, and 15 molecules of water, resulting in the molecular formula C₂₈₈H₃₃₀N₃₆Na₁₈O₄₈·15H₂O and a molecular mass of 5748.03 g/mol.

The substance is a white powder consisting of thin hexagonal plates. It is stable in solid form as well as in aqueous (watery) solution with a pH of 5 to 7, and has a melting point of about 138 °C (280 °F).

src: heartfailure.onlinejacc.org

History

During its development by Novartis, Entresto was known as LCZ696. It was approved under the FDA's priority review process on July 7, 2015. It was also approved in Europe in 2015.

src: heartfailure.onlinejacc.org

Society and culture

Trial design

There was controversy over the PARADIGM-HF trial -- the Phase III trial on the basis of which the drug was approved by the FDA. For example, both Richard Lehman, a physician who writes a weekly review of key medical articles for the BMJ Blog and a December 2015 report from the Institute for Clinical and Economic Review (ICER) found that the risk-benefit ratio was not adequately determined because the design of the clinical trial was too artificial and did not reflect people with heart failure that doctors usually encounter. On the other hand, in December 2015 Steven Nissen and other thought leaders in cardiology said that the approval of sacubitril/valsartan had the greatest impact on clinical practice in cardiology in 2015, and Nissen called the drug "a truly a breakthrough approach."

One 2015 review stated that sacubitril/valsartan represents "an advancement in the chronic treatment of heart failure with reduced ejection fraction" but that widespread clinical success with the drug will require taking care to use it in appropriate patients, specifically those with characteristics similar to those in the clinical trial population. Another 2015 review called the reductions in mortality and hospitalization conferred by sacubitril/valsartan "striking", but noted that its effects in heart failure people with hypertension, diabetes, chronic kidney disease, and the elderly needed to be evaluated further.

Cost

The wholesale cost for a year of sacubitril/valsartan in the USA is $4,560 per person as of 2015, but the cost to the NHS in the UK is less than £1,200 per person per year. Similar class generic drugs without sacubitril, such as valsartan alone, cost approximately $48 a year. One analysis found a cost of $45,017 per QALY.

src: heart.bmj.com

Research

The PARADIGM-HF trial (in which Milton Packer was one of the principal investigators) compared treatment with sacubitril/valsartan to treatment with enalapril. People with heart failure and reduced LVEF (10,513) were sequentially treated on a short-term basis with enalapril and then with sacubitril/valsartan. Those that were able to tolerate both regimens (8442, 80%) were randomly assigned to long-term treatment with either enalapril or sacubitril/valsartan. Participants were mainly white (66%), male (78%), middle aged (median 63.8 +/- 11 years) with NYHA stage II (71.6%) or stage III (23.1%) heart failure.

The trial was stopped early after a prespecified interim analysis revealed a reduction in the primary endpoint of cardiovascular death or heart failure in the sacubitril/valsartan group relative to those treated with enalapril. Taken individually, the reductions in cardiovascular death and heart failure hospitalizations retained statistical significance. Relative to enalapril, sacubitril/valsartan provided reductions in

• the composite endpoint of cardiovascular death or hospitalization for heart failure (incidence 21.8% vs 26.5%)
• cardiovascular death (incidence 13.3% vs 16.5%)
• first hospitalization for worsening heart failure (incidence 12.8% vs 15.6%), and
• all-cause mortality (incidence 17.0% vs 19.8%)

The favorable effect of sacubitril/valsartan was seen in all subgroups examined, including those based on age, sex, weight, race, NYHA class, presence or absence of reduced kidney function, diabetes mellitus, atrial fibrillation, hypertension, and prior hospitalization. Additional analyses of the trial demonstrated a meaningful representation of minority groups and well as a benefit in patients with an implantable cardiac device. Limitations of the trial include scarce experience with initiation of therapy in hospitalized patients and in those with NYHA heart failure class IV symptoms.

src: jaha.ahajournals.org

References

Source of the article : Wikipedia