Clinical trials failed Targacept into the nicotine receptor minefield

 In July 28th, USA Biotech Corp Targacept announced its nicotine receptor antagonist TC-5214 ADHD is a phase two clinical failure in bladder. Prior to this,TC-5214 has been in several antidepressant clinical trials failed. Now Targacept has finally decided to give up this shit.

Analysis: the core technology of Targacept is the neural nicotinic receptors, butthey struggled for many years in this field, there is no progress. The companyhas several years of trading below cash reserves, is now said to have$120000000 in cash, but only $80000000 market value, shareholders of thecompany's biggest hope seems not to do anything. They failed in Blzheimer,ADHD, depression, schizophrenia and 8 clinical trials, for a small company to no profit to have so many chances of failure is rare, although two years ago CEOwas out.

Targacept about the disease is now the big field of pharmaceutical industry.Blzheimer market is great but now we are on the disease occurrence,development, and treatment of know too little, the field of clinical failure rate as high as 99.6%. Depression is a high failure rate of disease, in addition to the mechanism responsible for the animal model is not accurate, outside, a majorproblem is the placebo effect greatly. Depression patients taking placebo over 70% will have the mood, so it is difficult to see the distinction between drug and placebo. Schizophrenia is a heavy disaster area, new drugs have recently listedare new forms of old drugs, only a new mechanism of drug Bitopertin now looks bleak for just this year, two phase 3 clinical failure.

But more is this complex disease are more likely to find the potential new target.

One of the main reasons is due to the complex etiology, it is difficult to finddifferences in patient gene gene. So now the common way is to use animalmodels to test target. Here are a few questions. An animal model is veryunreliable. The above mentioned these diseases are almost unique to human, so the "animal model" is almost a concept stultify oneself, like animal model of stuttering.

Two is in pursuit of the number of drugs now entering clinical enterprise culture,animal model after years of "improvement" is very sensitive, very easy to seethrough a variety of compounds of behavior change.

Three of these neurotransmitter receptors are easy to find active compounds of very high, but the compound really good selectivity is rare, especially in the high dose. So while you use a nicotine receptor antagonists, but in the use of dosemay also and many other receptors.

These factors determine the number of false positive preclinical data, causingcompounds are promising. The clinical development of no biological markerreliable, namely cannot choose the sensitive crowd, is also unable to confirm themechanism related activity. Consolation prize effect with very high, now in pharmaceutical companies, these drugs are at a distance.

Of course, Targacept is not necessarily an innocent boy, I do not know their ownminefields, after all, many large banks and big pharmaceutical companies to invest in the company or its cooperation. Only large potential rewards affect judgment, forget I was in Pavilion of Prince Teng or in Hongmen banquet.