A woman with multiple sclerosis (MS) says she has been left with debilitating side effects after the NHS switched her to a cheaper drug.
Julie Cowdrill is among scores of MS patients who say they have suffered a regression in their condition after being switched from a drug called Tysabri to one called Tyruko, with complaints that a “cost-cutting exercise” is coming at the expense of their health.
NHS England is hoping to save £1bn over the next five years by switching to biosimilar drugs – medicines that have been shown not to be clinically different from the original drug, but are made far more cheaply.
However, in Ms Cowdrill’s case, she has been left suffering from headaches and extreme fatigue, and has experienced worsenening mobility since she started taking the drug in December 2024.
“Myself and many others have said that it feels like we’ve regressed 10 or 15 years after all the work we’ve done to get better. It’s like the rug has been pulled from under you – it’s dreadful,” she told The Independent.
The Medicines and Healthcare products Regulatory Agency (MHRA) said it is “aware” that some patients have experienced side effects, but that a rigorous assessment has “demonstrated no clinically meaningful differences” between the drugs.
Ms Cowdrill first noticed her body was behaving unusually in 2006 when she was in her early twenties, after she suffered nerve damage in her eye. By 2009, at the age of just 28, she began to notice “literally everything” was going wrong with her health, and she was diagnosed with relapsing-remitting MS.
MS is a chronic autoimmune disease that affects the nervous system and disrupts communication between the brain and the body. There is no cure, but treatment and pain management are available to help patients manage their condition.
Due to the rapid progression of her disease, Ms Cowdrill was placed on Tysabri. While it did not reverse the neurological damage, she was able to return to her daily habits such as shopping, driving her car and taking her daughter to school.
Last April, she was told the drug could now be administered through an injection rather than an intravenous infusion, and she agreed to switch procedures.
However, an adverse reaction linked to how the drug was administered meant that by November, she was unable to walk and spent hours crying in pain in A&E at Queen Elizabeth’s Hospital in Birmingham. So doctors suggested switching to Tyruko.
“The nurse told me I could now take Tyruko and said it was exactly the same, and nothing would change. Since then, I’ve gotten worse every month. I’ve not relapsed, but my disability has worsened.
“My life is crumbling, my walking is just appalling, I’m falling every week. Every part of my body is worse since the switch.”
Despite requesting to return to Tysabri, which she took for 13 years without issue, Ms Cowdrill has been informed that only Tyruko and injections of Tysabri are available from now on, as part of a nationwide rollout.
Since communicating with others online, she has written a letter to NHS England, the MS Trust and the MS Society to outline concerns around the drug. The letter has been signed by 103 fellow patients from 31 different hospitals.
She has also launched a petition asking for access to Tysabri to be reinstated for those affected by the switchover. This has attracted more than 37,000 signatures.
At Charing Cross Hospital, about 170 patients have been switched back to Tysabri after suffering complications, including a relapse of their illness, from taking the biosimilar drug.
A spokesperson for the pharmaceutical company Sandoz, which manufactures the drug, said: “Tyruko (natalizumab) was approved by the UK medicine regulator (MHRA) based on no meaningful differences between Tyruko and Tysabri in terms of clinical efficacy and safety. Real-life patient data showed that switching from Tysabri to Tyruko was well tolerated.”
A spokesperson for the MS Trust said it had been contacted by patients who have noticed “significant symptom changes” after switching from Tysabri to Tyruko (both of which are natalizumab products).
“It is vital that we fully understand the experiences of people with MS when switching from one natalizumab product to another. We are talking to all stakeholders, including people with MS, to ensure that this data is collected and shared transparently with the MS community and the healthcare teams responsible for prescribing them,” the spokesperson said.
Laura Thomas, head of policy at the MS Society, said most people who have changed treatment have done so without issue, but some have reported problems.
“NHS England has said that it should always be possible for patients experiencing adverse events or deterioration on Tyruko to revert back to Tysabri IV [the version that is delivered intravenously]. We’re asking them to make sure that this is happening in practice.”
An NHS England spokesperson said the drugs have been shown to have no clinically meaningful difference in their safety or efficacy, but that it is liaising with the MHRA, manufacturers and patient groups following concerns raised by patients.
“Patient safety is our top priority,” the MHRA said. “We continuously monitor the safety of medicines on the UK market and are working to investigate these concerns using all available information, including reports from the Yellow Card scheme and data from the marketing authorisation holder for Tyruko.”
