Anti-obesity pills: Don't expect miracles
Obesity treatment: the revolution is postponed
Аптека.иаNew drugs designed to treat obesity, currently undergoing late phases of development, are combinations of previously approved drugs, and not true innovations, writes Ron Feemster in the journal "Pharmaceutical Executive".
This situation has developed after the failure that befell the company "sanofi-aventis" with its potential blockbuster Acomplia/Zimulti/Acomplia (rimonabant). As you know, in the fall of 2008 an increase in the frequency of cases of mental disorders with widespread medical use of the drug forced the French company to stop clinical trials of rimonabant and withdraw it from many markets. Literally immediately, other companies decided to take similar steps: Pfizer stopped phase III trials of its cannabinoid receptor antagonist otenabant; AstraZeneca plc, Merck &Co. did the same. R. Feemster, referring to Datamonitor, writes that in 2007-2008, when the situation with rimonabant worsened, the development of a total of 27 candidate drugs for the treatment of obesity was discontinued; so much was spent on these research programs (about $ 1.1 billion). USA), how much the entire market of drugs for the treatment of obesity costs today.
Unfortunately, the drugs that are now used to treat obesity are not without drawbacks. So, Xenical/Xenical (orlistat, "Roche") it can cause unpleasant gastrointestinal manifestations, Meridia /Meridia (sibutramine, "Abbott") – an increase in blood pressure. The antidepressant Zoloft / Zoloft (sertraline, Pfizer), prescribed for the treatment of obesity outside of approved indications (off-label), is used for a short course, which is not suitable for this category of patients.
As for about half a dozen combined drugs currently in development, none of them will reach the sales level predicted by Rimonabant – $ 2 billion. per year, the author of the article writes.
The US Food and Drug Administration (FDA), when issuing marketing permits for drugs for the treatment of obesity, requires that the reduction in body weight during therapy with them is on average 5% (compared with placebo). If this condition is not met, then at least 35% of patients should have a body weight reduction rate of 5%. Of the three candidates currently undergoing phase III development, not all meet the first condition.
So, at the end of 2009, Vivus plans to apply for marketing of Qnexa, a combination of phentermine – a derivative of amphetamine – and topiramate – an anticonvulsant. According to the results of the study, taking the drug for 28 weeks provided a 7.5% more pronounced reduction in body weight than placebo.
In the first half of 2010, Orexigen intends to apply for approval of Contrave, a combination of the antidepressant bupropion and the opioid receptor antagonist naltrexone. The latter is used to treat alcohol addiction. The combined drug showed a lower result than prescribed by the first of the above-mentioned criteria of the FDA. However, the drug reduces the risk of developing cardiovascular diseases, which is regarded as an argument in favor of making a positive decision to reimburse its cost.
The third of the products undergoing the final stage of development is lorcaserin from Arena Pharmaceuticals. The drug resembles the FDA-banned fenfluramine, but in comparison with it has a greater selectivity of action. However, the average weight loss when taking it does not reach 5% compared to placebo.
Drugs undergoing phase II development still look more promising, for example, tezofensin ("NeuroSearch") – an inhibitor of the reuptake of dopamine, serotonin and norepinephrine – allowed subjects with a body weight of about 100 kg to lose 13-15 kg. Fears are inspired by the triple mechanism of action of the drug: serious side effects can be detected during large-scale clinical trials.
Thus, in the next 5 years, it is not necessary to count on revolutionary breakthroughs in the mass pharmacotherapeutic treatment of obesity.
Based on PharmExec materialsPortal "Eternal youth" http://vechnayamolodost.ru