Research Update

23/08/2007

ReGen Therapeutics Plc today announces the results of a small scale study that is part of its clinical programme designed to explore the ‘antidormancy’ effect of zolpidem.

This study was a double-blind, Phase IIa study in twenty conscious, fully perceptive ambulant1 patients having various debilities as a consequence of brain damage. It was performed in collaboration with ReGen’s subsidiary, Guildford Clinical Pharmacology Unit Ltd., UK and investigators at the Walko Medical Centre in Springs, South Africa where the ‘antidormancy’ effect of zolpidem was first discovered.

The study compared various single doses of a novel sublingual spray formulation (placebo, 2.5mg, 5mg, 10mg) with an existing tablet formulation (placebo, 10mg) in terms of the onset and degree of sedation. It also looked for preliminary signs of efficacy, although the study was small and only single doses of drug were given.

The study showed the following:

  • 2.5mg spray regimen was no more sedative than placebo
  • 10mg and 5mg spray regimen induced sedation in a dose responsive manner
  • The spray showed faster onset of action (sedative effect) than the tablet
  • The 5mg spray induced the same peak level of sedation as the 10mg tablet
    - 15 minutes compared with 90 minutes respectively.Commenting on these findings ReGen’s Medical Director Dr. Andrew Sutton said, “We are delighted to have obtained such clear cut evidence that a spray is absorbed faster and more completely than tablets because this will enable patients to control the effect more accurately. Most importantly a dose of 2.5mg caused no more sedation than placebo, suggesting the possibility that repeated 2.5mg spray doses will show efficacy without undue sedation.”Percy Lomax, ReGen Chairman and Chief Executive added “Based on these results we now have the confidence to continue the development of novel zolpidem formulations for the treatment of brain dormancy2. We are now reviewing options to achieve this.”Further announcements will be made in due course.

    For more information, please contact:

    Andrew Marshall
    Greycoat Communications
    Tel: 020 7960 6007
    Mobile: 07785 297111

    Percy Lomax
    ReGen Therapeutics Plc
    Tel No 020 7153 4920

    Andrew Baker/Rory Creedon/Cecil Jordaan
    HB Corporate
    Tel No 020 7538 1166

    Notes to Editors:

    1. Ambulant means patients who are able to walk around.
    2. Brain dormancy is an expression used to describe an area of the brain where the cells are not dead, but are not functioning normally.

    Zolpidem was found by Dr HW Nel who is now a consultant to ReGen to produce unexpected and marked improvements in motor and cognitive deficits suffered by patients after brain injury. However, as the tablets were designed to produce sedation some 30% of his patients had to stop the medication due to heavy daytime sedative effects.

    ReGen’s thesis is that zolpidem can reverse ‘dormancy’ at sites removed from a primary site of brain damage (e.g. stroke, head trauma, viral infection, near-drowning). This thesis is derived from observations of open case clinical studies in over 200 patients.

    Thus, where those functions controlled by the dormant brain areas have been normalised the following improvements have been seen:

    • Aphasia (speech cognition)
    • General cognition and IQ
    • Ataxia (limb coordination/posture)
    • Hearing
    • Basic reflexes (swallowing and continence)

    ReGen has filed an application for a use patent for the use of zolpidem in ‘dormancy’.
    ReGen is now carrying out background scientific research to discover, among other things, the precise mode of action of zolpidem in this situation.ReGen wishes to stress that it believes the overwhelming market for this drug is for ambulant1 patients and whilst it has a use in Persistent Vegetative State (PVS) this is not the main direct audience.

  • Further ReGen wishes to confirm that it does not consider that it is for ReGen to participate in the medical ethics debate about the use of zolpidem in PVS patients. What ReGen is working on is a reversal of brain dormancy2. The licensing of any drug is the responsibility of the Health Authority and its use is within the doctor patient relationship and ReGen will make no comment on that.