Nalmefene

17-cyclopropylmethyl-4,5α-epoxy-6-methylenemorphinan-3,14-diol

march 1 2013

Lundbeck will be celebrating news that European regulators have issued a green light for Selincro, making it the first therapy approved for the reduction of alcohol consumption in dependent adults.

Selincro (nalmefene) is a unique dual-acting opioid system modulator that acts on the brain’s motivational system, which is dysregulated in patients with alcohol dependence.

The once daily pill has been developed to be taken on days when an alcoholic feels at greater risk of having a drink, in a strategy that aims to reduce – rather than stop – alcohol consumption, which some experts believe is a more realistic goal.

Clinical trials of the drug have shown that it can reduce alcohol consumption by approximately 60% after six months treatment, equating to an average reduction of nearly one bottle of wine per day.

In March last year, data was published from two Phase III trials, ESENSE 1 and ESENSE 2, showing that the mean number of heavy drinking days decreased from 19 to 7 days/month and 20 to 7 days/month, while TAC fell from 85 to 43g/day and from 93 to 30g/day at month six. However, the placebo effect was also strong in the studies.

According to Anders Gersel Pedersen, Executive Vice President and Head of Research & Development at Lundbeck, Selincro “represents the first major innovation in the treatment of alcohol dependence in many years,” and he added that its approval “is exciting news for the many patients with alcohol dependence who otherwise may not seek treatment”.

Alcohol dependence is considered a major public health concern, and yet it is both underdiagnosed and undertreated, highlighting the urgent need for better management of the condition.

In Europe, more than 90% of the 14 million patients with alcohol dependence are not receiving treatment, but research suggests that treating just 40% of these would save 11,700 lives each year.

The Danish firm said it expects to launch Selincro in its first markets in mid-2013, and that it will provide the drug as part of “a new treatment concept that includes continuous psychosocial support focused on the reduction of alcohol consumption and treatment adherence”.

Nalmefene (Revex), originally known as nalmetrene, is an opioid receptor antagonistdeveloped in the early 1970s, and used primarily in the management of alcoholdependence, and also has been investigated for the treatment of other addictions such aspathological gambling and addiction to shopping.

Nalmefene is an opiate derivative similar in both structure and activity to the opiate antagonist naltrexone. Advantages of nalmefene relative to naltrexone include longer half-life, greater oral bioavailability and no observed dose-dependent liver toxicity. As with other drugs of this type, nalmefene can precipitate acute withdrawal symptoms in patients who are dependent on opioid drugs, or more rarely when used post-operatively to counteract the effects of strong opioids used in surgery.

Nalmefene differs from naltrexone by substitution of the ketone group at the 6-position of naltrexone with a methylene group (CH₂), which considerably increases binding affinity to the μ-opioid receptor. Nalmefene also has high affinity for the other opioid receptors, and is known as a “universal antagonist” for its ability to block all three.

1. US patent 3814768, Jack Fishman et al, “6-METHYLENE-6-DESOXY DIHYDRO MORPHINE AND CODEINE DERIVATIVES AND PHARMACEUTICALLY ACCEPTABLE SALTS”, published 1971-11-26, issued 1974-06-04
2.  Barbara J. Mason, Fernando R. Salvato, Lauren D. Williams, Eva C. Ritvo, Robert B. Cutler (August 1999). “A Double-blind, Placebo-Controlled Study of Oral Nalmefene for Alcohol Dependence”. Arch Gen Psychiatry 56 (8): 719.
3.  Clinical Trial Of Nalmefene In The Treatment Of Pathological Gambling
4.  http://www.fda.gov/cder/foi/label/2000/20459S2lbl.pdf
5. “Efficacy of Nalmefene in Patients With Alcohol Dependence (ESENSE1)”. “Lundbeck submits Selincro in EU; Novo Nordisk files Degludec in Japan”. thepharmaletter. 22 December 2011.
6. Nalmefene Hydrochloride Drug Information, Professional