Risdiplam: What it is, How it works and Other FAQs
Risdiplam: What it is, How it works and Other FAQs
Page last checked: 19th December 2022
Last updated: 17th March 2023
Risdiplam is a small molecule drug that targets the ‘back up’ survival motor neuron 2 (SMN2) gene to produce more SMN protein. It’s only used to treat 5q variant spinal muscular atrophy (5q SMA).
People with SMA don’t have enough of a protein called ‘survival motor neuron’ (SMN) protein. This protein is essential for the nerve cells, known as motor neurons that help control muscles. Motor neurons are found in the brain and spinal cord and they make contact with muscles.
The SMN protein is made in our cells from two genes, SMN1 and SMN2. People who have SMA lack the SMN1 gene but have the SMN2 gene, which mostly produces a short SMN protein that does not work as well as a full-length protein.
Risdiplam specifically modulates how effectively the survival motor neuron 2 (SMN2) gene is used to make SMN protein. This is essential for the health of nerve cells that control muscle movement. Signals (called messenger RNAs) are generated from SMN2, and risdiplam specifically interacts with these, resulting in more SMN protein being made by cells throughout the body.
Risdiplam is manufactured by the pharmaceutical company Roche under the trademark EVRYSDI™.
Read more about how it works here.
Risdiplam distributes throughout the body to many different types of cell, tissue and organ, including the brain, spinal cord, muscles and blood.
Risdiplam is given in liquid form with a prescribed dose based on a patient’s weight. It should be taken once daily after a meal, at approximately the same time each day by mouth (orally) or feeding tube, using the provided syringe.
It may be possible to have risdiplam delivered to your home by a homecare provider, who will deliver risdiplam as a liquid. The alternative is that it will be provided to the specialist neuromuscular centre as a powder, that is then made into a liquid by the pharmacy using purified water. Where and how you / your child receive the treatment is ultimately the responsibility of the clinical team at your specialist neuromuscular centre.
Risdiplam is provided in a bottle in a box. The bottle should be kept upright in a fridge at a temperature between 2˚C and 8˚C. It is stable for 64 days after the pharmacist prepares it. If necessary, the oral solution may be stored at room temperature (below 40˚C) for no more than a total of 120 hours (5 days). The oral solution should be returned to the fridge when it is no longer necessary to keep the bottle at room temperature. The total time outside the refrigerator (below 40˚C) should be monitored. The oral solution should be discarded if it has been stored at room temperature (below 40°C) for more than a total of 120 hours (5 days), or for any period of time kept above 40°C.
Any drug, including ones that are commonly prescribed or sold over the counter, may cause possible side effects. Side effects of medications are reported and recorded during their clinical trials. They’re also picked up through the ongoing systems that are in place to monitor medications and their use in the ‘real world’. All possible side effects are listed in the Patient Information Leaflet that is given with any medication. They are grouped as:
- very common
For risdiplam, possible side effects are:
Very common: may affect more than 1 in 10 people
Common: may affect up to 1 in 10 people
- mouth sores
- bladder infection
- joint pain
These and any rare or very rare side effects are listed in Roche’s Patient Information Leaflet which covers other questions as well (see below).
On 5th January 2023, the Roche Medical Information team responded to our question, ‘Are there any updates on the possible impact of Evrysdi on fertility and pregnancy, including advice to people who are considering taking this treatment?’
"Please be advised that there is currently no further information available on the impact of Evrysdi on fertility and pregnancy nor on the advice patients should receive on this matter, beyond the Evrysdi Patient Information Leaflet (PIL) or Summary of Product Characteristics (SPC). We would encourage patients to continue to consult their doctor if they have any further questions. Their doctor will be able to provide advice to them based on their personal medical history."
Different hospitals have different processes and timelines which can affect how long it takes for your risdiplam supply to get through the hospital system. Times may vary for how long it takes for your prescription to be finalised. They may also vary for how long it takes for your hospital paperwork to then be referred to and reach the Homecare Company, if one is being used. Once the Homecare Company has received your prescription and registration form from the hospital, the Company will contact you to welcome you to the service. They will answer any questions you may have and agree delivery details with you.
You will find the answer to many of your questions in Roche’s Patient Information Leaflet and will have an opportunity to discuss any further questions you may have with your clinician. The leaflet covers:
1. What Evrysdi is and what it is used for
2. What you need to know before you or your child take Evrysdi – this includes information about pregnancy, contraception, breast-feeding and male fertility
3. How to take Evrysdi
4. Possible side effects
5. How to store Evrysdi
6. Contents of the pack and other information
There are now three licenced drugs funded by the NHS for people who have SMA; until 2018, there were none. Different eligibility criteria apply to each one. There have been no studies to date that directly compare the treatments. You should discuss treatment options with your / your child’s clinical team in your specialist neuromuscular centre. Together you will be able to discuss risks and benefits of any of the treatments that are potentially possible and make an informed decision as to which one is best for you / your child.