Neurosciences - Enzyme Replacement Therapy

You have been given this leaflet as your doctor and MDT team feel you may benefit from modifying treatment for your metabolic disease.

You may already be established on treatment, either from a different adult metabolic centre or from a children’s team and you have transitioned to our adult team. Therefore, some of the information may not be relevant to you. However, there may be sections that highlight differences between paediatric and adult service.

There are two types of treatments available for certain metabolic conditions that have been licensed for use, and they are either in the form of intravenous infusion or there are some that can be taken as an oral medication.

Oral therapy is not available for everyone, as it is dependent on what metabolic condition you have, and whether your mutation is amenable to it.

If oral therapy is available to you, the team will inform you at your clinic appointment and you will receive separate information about this.

There may be a possibility of accessing treatments through a clinical trial if one is ongoing for your condition. If you wish to learn more about clinical trials, please speak to your metabolic consultant.

This leaflet explains what enzyme replacement is and answers some of the common questions, to alley any fears or concerns.

What is ERT?

ERT is a manufactured enzyme which will replace the enzyme that is either missing or depleted in your body.

Why do I need ERT?

It will be given to replace this enzyme that is either missing, or to help what enzyme you have to function better. The aim of the treatment is to prevent storage material in particular organs in your body, and affectively slow down the progression of the disease.

Is ERT painful?

ERT is administered via an intravenous infusion and this means a needle is inserted into the arm or hand to administer the drug. When the needle is being inserted a sharp scratch will be felt but the infusion itself causes no pain.

What are the side effects?

It is not uncommon for patients to have a slight reaction to the treatment such as vomiting, hot or cold flushes.

There is a very small risk that patients can have a severe allergic reaction but this is very rare.

There are steps that can be carried out to manage a reaction, if they were to occur. Pre-medication can be given one hour before the infusion commences to help prevent a reaction occurring, and there are several options that can be tried. The infusion can also be given at a slower rate.

The nurse on the ward will explain more about this before your first infusion.

How often do I have ERT?

Most ERT’s are given once a fortnight, although some are weekly, depending on your condition. This is something that the nurse will discuss with you when arranging your first infusion.

Where do I have my treatment?

You will have your infusion in a day-case unit at Salford Royal Hospital. The details of the unit will be on your appointment letter.

Specialist nurses who work in the Mark Holland Metabolic Unit will administer and monitor you having ERT for the first few infusions in hospital.

The number of infusions you have in hospital will depend on which ERT you have, and this will be discussed with you before the treatment starts.
 
When you have completed the number of infusions in hospital successfully you will be able to continue with the infusions at home.

Who does my infusion at home?

All treatments can be administered at home and this will be discussed with the nurse on the unit.

The hospital has access to home care companies, and you will be referred to a team prior to going home. A home care nurse will contact you prior to your last infusion at hospital and they will arrange to see you at home before your first infusion at home is due.

They will administer the treatment when you go to home care and you will meet three different nurses who will do your infusion on a rotational basis. This is to ensure that nurses can cover each other during episodes of sickness and holidays.
 
There is an option for you, or a family member to learn to administer the treatment once you are established on treatment.

You can discuss this with the metabolic or homecare nurse if you wish to find out more about becoming independent with your infusions.

Are there any requirements for having my treatment at home?

The ERT needs to be stored in a fridge and you will need to monitor the temperature of the fridge daily. You can use your own domestic fridge to store the ERT or a separate medical fridge can be provided by the home care company.

If you choose to use your domestic fridge, it needs to go in a tupperware box, and the homecare company can provide an external thermometer if you do not have one on your fridge.

You will also need to accept a delivery for the ERT and ancillaries once a month, to the address where you will be having your treatment. Therefore, you will be required to provide a number to the homecare company that you can easily be contacted on, for you to arrange the delivery.
 
The home care company will provide you with the contact numbers for appropriate teams for arranging deliveries and arranging treatments with the nurse.

Can I eat and drink during my infusion?

Yes, you can eat and drink normally on the day of your infusion.

Can I drive after my infusion?

You can drive after the infusion, but we recommend that you bring someone with you for the first few infusions as some patients have reported feeling tired after the infusion. You may wish to bring someone in case you have a reaction and do not feel well enough to drive home.

How long do I have to have treatment for?

ERT is not always a lifelong treatment and there are several reasons it may be stopped. There are certain requirements that need to be met to remain on treatment.

You will be required to attend clinic appointments and have yearly assessments. Failure to do so can result in the treatment being discontinued.

Treatment can be stopped if you miss several infusions if there is no reasonable explanation for the missed infusions.

You may change ERT if another treatment becomes available to you.

Your metabolic consultant will discuss stopping treatment with you, if you are diagnosed with another terminal illness, or your results show you no longer benefit from treatment. This may be discussed at each clinic appointment.

What will happen if I need to miss a treatment?

You may need to miss an infusion for several reasons but most commonly it would be due to a holiday or because of an illness. It is okay to miss the occasional infusion within a 12-month period.

We would not authorise you to take your infusion on holiday due to the risks involved and you can discuss this with the nurse or pharmacist.

You can choose to arrange to have your infusion before you go on holiday and have another infusion on your return to prevent missing an infusion. However there needs to be a certain amount of days in between each infusion. If you are unsure you can contact the metabolic nurse or discuss with your home care nurse who will contact the team if required.

If you are unwell when your infusion is due, we would advise you to contact your home care nurse. They may decide to delay your infusion to another day, or they can advise you to miss that infusion depending on your symptoms.

If you have been started on antibiotics, we would advise you to miss your ERT until completion and until you feel well. Being unwell and being on antibiotics will increase your risk of having a reaction.

If you are admitted into hospital, you must not, in any circumstance have your infusion whilst an inpatient. This is because you are at an increased risk of having a reaction when you are unwell. Always, contact the metabolic team if you are able to if you are admitted into hospital.

For any planned admissions, you may want to plan that you do not have any ERT in your fridge if a prolonged stay is anticipated. You can arrange this directly with the homecare company.

If you have a treatment break due to a prolonged holiday or hospital admission, you must contact the metabolic team before restarting treatment. They will assess whether you need to be restarted in hospital and this will depend on the length of time you have been off treatment.

Can I have my treatment when I have had a vaccination?

You can continue with ERT when a vaccine is required and you must follow local guidelines for advice regarding vaccines.

You can also find advice on British Inherited Metabolic Disease Group’s (BIMDG) website:
www.bimdg.org.uk
 
If you are unsure about vaccine or any other question in relation to treatment, please contact the metabolic team below.

Contact

The Mark Holland Metabolic Unit on 0161 206 1899
Email: MHMU@nca.nhs.uk