Effects of GABA Modulator AZD7325 on Cutaneous Sensation

GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the human brain. For years, drugs that enhance its effects (e.g., benzodiazepines such as diazepam/Valium) have been used to treat various diseases such as epilepsy, insomnia, anxiety or movement disorders. However, the use of these medications is often compromised because of their side effects, such as sleepiness, memory problems, and addiction.

Therefore, effort has been made to develop drugs that act more selectively in the brain to exert the positive therapeutic effects and are devoid of the unwanted side effects. AZD7325 is one of these drugs. It has been tested in more than 700 people and so far proved to be generally well tolerated. Positron emission tomography (PET) study in humans demonstrated that AZD7325 binds to GABA A receptors in the brain after a single dose. Early clinical studies have shown that it has less sedative and cognitive adverse events as compared with a benzodiazepine lorazepam.

The investigators now wish to evaluate if effects of AZD7325 can be objectively measured in healthy volunteers and to establish which of the drug's outcomes could be utilised for further studies in patients with neurological diseases.

The investigators are especially interested in the effects of AZD7325 on manual dexterity and skin sensation of the hand. This can be assessed by a number of simple non-invasive tests of object manipulation and detection of different sensory stimuli such as touch, vibration, or temperature. Recent studies show that healthy individuals who performed better in similar tasks had more GABA in relevant areas of their brain. If performance in these tasks in healthy volunteers can be improved by enhancing GABA effects in the brain with AZD7325, this would create the grounds for the use of this medication to treat symptoms of certain neurological disorders in which motor control and sensation of the hand is impaired (e.g., polyneuropathy).


Eligibility Criteria:
Inclusion Criteria:

* Male adults aged 18 to 55 years (extremes are included)
* A body weight resulting in a body mass index (BMI) of 18-30 kg/m2 (extremes included) using the formula BMI = body-weight \[in kg\] / body-height \[in m\]2
* Able and willing to sign the Informed Consent Form prior to screening evaluations.
* History of good physical and mental health as determined by history taking and laboratory examinations, ECG, blood pressure and heart rate recordings as judged by the investigator
* Willing not to consume alcohol or to smoke or chew tobacco on days of assessments
* Subjects must be willing to avoid unprotected vaginal intercourse with women of child bearing potential (see above under 3.5) or donating sperm for the duration of the study and a further 1 week after drug administration.

Exclusion Criteria:

* History of allergy/idiosyncrasy to AZD7325 or chemically related compounds or excipients which may be employed in the study or to any other drug used in the past
* Subject has taken systemically (po, iv) any potent or moderate CYP3A4 or CYP2C9 inhibitor, 1 month prior to screening (topical or inhaled are permitted) such as: aprepitant, barbiturates, carbamazepine, clarithromycin, erythromycin, cyclosporine, diltiazem, efavirenz, fluconazole, HIV protease inhibitors, glucocorticoids, itraconazole (oral/IV), ketoconazole, nefazodone, nevirapine, phenytoin, pioglitazone, primidone, rifabutin, rifampicin, telithromycin, St. John's wort, verapamil
* Use of any prescription drug judged by the investigator as potentially interfering with this trial within two weeks prior to the first dosing, except for topical medication without systemic exposure
* Clinically relevant history or presence of any medical disorder, potentially interfering with this trial
* Clinically relevant abnormal laboratory, ECG, HR or BP at screening as judged by the investigator
* History of or current abuse of drugs (including prescription medication) or alcohol or solvents
* Smoking in excess of 5 cigarettes per day or the equivalent within 28 days prior to the screening visit
* Smoking or chewing of tobacco or consume of alcohol, 24 hours before and on the days of assessment
* Subject is family member or in the employment line management of study personnel
* Subject has abnormal screening laboratory values
* Subject's partner is planning pregnancy within 3 months of last dosing
* Participation in an IMP intervention trial within last month or more than four in the previous 12 months
* Abnormal responses in the object manipulation task and psychophysical measures, SDMT, VAS outside 95% confidence interval of normal at screening visit
* Subjects with a history of epilepsy, seizures or episodes of unexplained and unprovoked loss of consciousness