Prion diseases and Creutzfeldt-Jakob disease (CJD) 

  • What are prion diseases?

    Prion diseases are a group of rare conditions which affect both humans and animals. These diseases cause fatal damage to the brain.

    There are three distinct causes of the human diseases:

    • They can develop spontaneously for unknown reasons. This is called sporadic CJD (sCJD) and is the most common form of human prion disease.
    • They can be inherited as a result of a faulty gene. This is known as inherited prion disease or familial CJD.
    • They can be acquired as a result of exposure to prions in the environment. For example, variant CJD (vCJD) is acquired by eating food contaminated with BSE, a prion disease in cattle.
  • What causes sporadic CJD?

    Sporadic CJD is caused when healthy proteins, which exist normally in the human body, spontaneously become misshapen and form chains that build up in the brain.

    These chains of misshapen proteins, which are called prions, stick to other healthy prion proteins causing them to become misshapen too.

    This process repeats itself and the disease spreads through the brain.

    This build-up of abnormal prion proteins causes brain cells to die affecting memory, thinking, talking, balance, movement and behaviour and eventually leads to the death of the patient.

  • What treatment is currently available for CJD?

    There is no treatment or cure for CJD. At present, caring for patients with CJD involves trying to keep the person as comfortable as possible and using medicines to reduce symptoms.
  • What is the outlook for a patient diagnosed with CJD?

    While a few patients may live for a year or more, most sadly die within four to six months of symptoms starting and on average within six weeks of being diagnosed.
  • How many people a year are diagnosed with CJD?

    Approximately 120 new cases of sporadic CJD are diagnosed in the UK each year.

    Around one in every 5,000 deaths in the UK is due to CJD.

    Sporadic CJD occurs at the same level in all countries so this equates to approximately 10,000 new cases a year worldwide.

  • PRN100 treatment

  • What is the PRN100 treatment?

    PRN100 is an artificially manufactured antibody which has been created in the laboratory.
  • How does the treatment work?

    CJD is caused when healthy proteins which exist normally in the human body become misshapen and build up in the brain. These misshapen proteins, which are called prions, stick to other healthy proteins causing them to become misshapen too and the disease spreads through the brain.

    Our immune system produces antibodies to fight infections which invade the body. However, as abnormal prions are made of one of the body’s own proteins, our immune system does not make antibodies to fight them.

    The PRN100 treatment is an artificially manufactured antibody which has been created in the laboratory and can be given to the patient by a drip into a vein in the arm or injected into the fluid surrounding the brain.

    We believe the antibody works by binding tightly to normal proteins in the brain. This prevents abnormal prions from being able to attach themselves to healthy proteins, meaning that they cannot grow and cause devastation throughout the brain. 

  • Which form of CJD is this treatment for?

    We will consider this treatment for a patient with rapidly progressing CJD.

    In most cases, patients who have a rapidly progressing form of prion disease will be suffering with sporadic CJD (sCJD).

    At this time, we are not offering the treatment to a patient with a slower progressing form of the disease, such as inherited prion disease. We want to understand more about the potential side effects of the treatment.

  • How will the patient receive the treatment?

    The first treatment will be given as a slow infusion (a drip) into a vein in the arm over several hours. We will begin with a very low dose.

    Our team of experts will monitor the patient closely during the treatment and over the following days. We will take samples of blood and spinal fluid, perform scans and monitor the patient’s condition continuously looking for any response to the drug or side effects.

    Using the data from this monitoring, the clinical team will decide whether or not to proceed with further sessions of the treatment and whether to increase the dose. Their decisions will need to be approved by independent experts from UCLH’s PRN100 oversight sub-committee.

    If, after two treatment sessions at the maximum dose, we find that an insufficient quantity of the drug has reached the brain tissue where it needs to be in order to work, we will consider injecting the drug directly into the fluid surrounding the brain. This would be done using a well-established surgical procedure.

  • Has the treatment been used in humans before?

    No, this will be the first time the treatment is used in a human.
  • What do we hope/expect the results of the treatment to be?

    We hope that the drug may delay the progression of the disease. However, as this is the first time this treatment is being used in humans we cannot predict what the outcome will be.

    We are preparing for a range of possible outcomes including the treatment having no measurable effect, and the treatment slowing or halting the progression of the disease. The treatment is not expected to reverse any damage already caused to the brain.

    A key issue will be whether a sufficient quantity of the drug is able to cross the blood brain barrier to reach the brain tissue where it needs to work. We hope that by giving the treatment by a drip into the blood this will occur. However, if this does not happen, we will consider injecting the drug directly into the fluid surrounding the brain.

    We may find that it is not possible to tackle the disease unless the treatment is given at such a high dosage that it causes serious side effects. This situation would be similar to some chemotherapy treatments for cancer which always cause side effects at effective doses.

  • What steps are you taking to reduce the risks of the treatment?

    We will start with a very low dose of the treatment and closely monitor the patient’s response.

    We will take samples of blood and spinal fluid, perform scans and continuously monitor the patient’s condition.

    Using the data from this monitoring, the clinical team will decide whether or not to proceed with further sessions of the treatment and whether to increase the dose. Their decisions will need to be approved by independent experts on UCLH’s PRN100 oversight sub-committee before the treatment programme can continue.

  • What are the potential risks/side effects of the treatment?

    All drugs carry a risk of side effects and are toxic at high enough doses. The PRN100 treatment has not been used in humans before so we are giving it to a patient under very tightly controlled conditions.

    Any new drug can have unexpected side effects such as an allergic reaction, changes in blood clotting or an adverse activation of the immune system.

    It is possible that side effects appear after a single dose or at a later date.

    We will monitor the patient extremely closely for evidence of side effects and will reduce or stop treatment if they occur, and give supportive treatment as appropriate.

    While there is a chance of serious side effects and uncertainty of benefits, we felt it was important for a patient to have the opportunity to be able to consider this drug as there are no other treatment options available for this rapidly fatal disease.

  • If the treatment is successful, will it be available to more patients with CJD?

    We will await the response of the first patient to this treatment before we consider a second patient.
  • Legal and governance arrangements

  • Is the PRN100 treatment a licensed medicinal product?

    No it is unlicensed. The treatment is being given to a patient under a “Specials” exemption following confirmation from the Court of Protection that it is lawful to do so and in the patient’s best interests.
  • What is a “Specials” exemption?

    A “Specials” exemption permits a healthcare professional to treat an individual patient with an unlicensed drug when their special clinical needs cannot be met by a licensed product on the market.

    The UK “Specials” scheme is overseen by the Medicines and Healthcare products Regulatory Agency (MHRA) which has published a guidance note on the manufacture and supply of specials entitled The supply of unlicensed medicinal products (“specials”).

  • What was the selection process/criteria?

    We selected a patient with a rapidly progressive form of CJD but for whom the disease was not at such an advanced stage that the treatment could not be expected to have an effect.
  • Has the patient agreed to receiving this treatment?

    The patient and their family expressed their wish to receive this treatment and supported UCLH’s court application.
  • Is this treatment part of a clinical trial/research study?

    No. This treatment is being given to a patient following confirmation from the Court of Protection that it is lawful to do so and in the patient’s best interests.
  • Will this treatment be part of a clinical trial in future?

    A limited amount of PRN100 has been made. If we do see encouraging results, we will take steps to develop further supplies with a view to progressing to a clinical trial in future.
  • Which UCLH committee approved the use of this treatment?

    In order to provide this treatment to a patient, UCLH created a PRN100 oversight committee, independent of the MRC Prion Unit at UCL and treating clinicians.

    Our senior leaders, and world-leading clinicians and researchers, many of whom hold joint positions with our academic partner, UCL, are committee members.

    They have been joined by external experts in prion disease, lawyers and patient advocates from the charity Cure CJD Campaign.

    The group has considered the numerous and complex clinical, safety, legal and ethical issues arising from the potential use of this unlicensed treatment for CJD.

    A sub-committee of this group, comprising senior clinical leaders, will monitor the clinical team’s decision-making throughout the treatment programme. The sub-committee will need to approve the clinical team’s decisions about dosage levels and administration before treatment can progress.

  • Has the Medicines and Healthcare products Regulatory Agency (MHRA) approved the use of this treatment in patients?

    Approval from the MHRA is not needed because this is an NHS treatment, using an unlicensed drug, provided under a legal “Specials” exemption. This is not a clinical trial.

    However we have discussed the proposed use of the treatment with the MHRA and they have confirmed that our plans are appropriate and in keeping with their guidance.

  • How will the results of the treatment be shared/made public?

    We aim to publish a report in a peer-reviewed medical journal.
  • Stakeholder organisations

  • What is the Medical Research Council (MRC) Prion Unit at UCL?

    The Medical Research Council (MRC) Prion Unit at UCL (University College London) is a national centre of excellence for research into prion disease.

    It was established in 1998 at the request of the Government to tackle public health problems caused by prions and to develop treatments.

    The Unit is core funded by the MRC but integrated within UCL.

  • What is the National Prion Clinic (NPC)?

    The National Prion Clinic (NPC) is the NHS national referral centre for prion disease. It is part of University College London Hospitals NHS Foundation Trust (UCLH).

    The NPC is funded by the NHS to provide diagnosis and care for patients with, or suspected to have, any form of human prion disease.

    Around 120 patients a year with sporadic CJD are referred to the NPC. The NPC also cares for most families with inherited prion disease and acquired prion diseases.

    The clinic works in partnership with the MRC Prion Unit at UCL.

  • What is UCLH’s involvement in the PRN100 treatment?

    UCLH will be providing the treatment to a patient.
  • What is UCL’s involvement in the PRN100 treatment?

    Researchers at the MRC’s Prion Unit developed the treatment. On 1 June 2017 the Unit transferred to University College London (UCL).
  • What is the Medical Research Council’s involvement in PRN100?

    Researchers at the MRC’s Prion Unit developed the PRN100 antibody as a potential treatment for patients with prion disease.

    The manufactured product belongs to the MRC.

    The MRC has provided the PRN100 antibody to UCLH for use in patients with prion disease.

  • Have any other organisations contributed to the development of this treatment?

    We would like to extend our thanks to the NIHR UCLH Biomedical Research Centre, the JP Moulton Charitable Foundation, the Medical Research Foundation and the Cure CJD Campaign charity for their support in the development and use of PRN100.

  • Further information

  • I am a member of the public, who can I speak to for further information about this treatment?

    Please contact the National Prion Clinic (NPC) team on 020 7679 5142 or email uclh.prion.help@nhs.net

    The Cure CJD Campaign charity has produced the following useful video explaining prion disease and the PRN100 treatment:

    https://www.curecjd.org/research

 Contact details

National Prion Clinic (NPC)
National Hospital for Neurology and Neurosurgery
Box 98
Queen Square
London, WC1N 3BG

Patient enquiries
Telephone: 020 3448 4037 / 020 3448 4038

GP enquiries
Telephone: 020 3448 4037 / 020 3448 4038
Fax: 020 3448 4046
Email: uclh.prion.help@nhs.net

Service manager - Michele Gorham
Email: uclh.prion.help@nhs.net