TV Review: Bittersweet Medicine

'Bittersweet Medicine' is an aptly named short documentary from the BBC which follows the first patient treated by the NHS with a new drug called Libmeldy. It simultaneously tells the story of the patient, Teddi, and her older sister, Nala, for whom it was too late to receive the life-saving treatment.

Teddi and Nala Shore live with their parents in Northumberland. At the time of initial filming, they are just ten months and two years old, respectively. Both have metachromatic leukodystrophy (MLD), which is a genetic disease, caused by a single faulty gene, where those affected cannot produce a critical enzyme called arylsulfatase A. This enzyme helps break down sulfatides, which are abundant in the brain, where they act as essential components of myelin sheaths – the protective layer around cells in the brain and nervous system. Without arylsulfatase A, sulfatides build up in the body and gradually destroys the myelin sheaths. As a result of this slow deterioration, the disease often does not present in children until irreversible damage has happened.

It was indeed Nala's symptoms that alerted doctors to Teddi's condition. Ally and Jake, the parents of the girls, describe how they watched their 'cheeky' eldest girl slowly begin to exhibit worrying signs of illness. Knowing that something was wrong, they took her into hospital and received the devastating diagnosis after an MRI scan. If two parents are carriers of the faulty gene, each of their children has a one in four risk of developing the condition. It was an unimaginable heartbreak for Ally and Jake, the parents, who say that they didn't think they could be so unlucky as to have both girls affected.

It is traditionally a terminal diagnosis, where families must face the prospect of watching their children gradually lose all physical ability. During the documentary, we hear from Professor Simon Jones, consultant at the Manchester Centre for Genomic Medicine, who expresses regret at how there has been no treatment to offer these families for decades.

MLD, if caught very early, can now be treated with a personalised gene therapy treatment called Libmeldy. We hear from the CEO of Orchard Therapeutics, the pharmaceutical company that manufactured Libmeldy, who explains that it has taken 20 years to get to the point of offering this drug on the NHS but that its demonstrated curative effect is remarkable, allowing children to live out potentially full lives that otherwise would have been cut short. The drug can only be administered if the condition is diagnosed early, typically before symptoms show, and it is for this reason that Teddi is eligible, but Nala is not. This has been a source of joy among the pain for the girls' parents, who say that Nala has saved Teddi's life.

In Royal Manchester Children's hospital, we see Teddi undergoing the process of filtering out her stem cells so they can be sent off to Milan, where a working version of the gene will be inserted into them, and subsequently back into her. She takes her first steps in hospital, a heart-breaking representation of how young she is and simultaneously an incredible reminder of how this treatment will allow her to continue to walk.

The documentary goes on to share the story of two other families whose children were involved in the clinical trials for the drug. The scenes of them running around and playing make it impossible to imagine that they were ever once affected. They are shining examples of the curative effect of the treatment. Unfortunately, we learn that these families have something in common with the Shore family, an affected older child whose illness allowed for the early diagnosis of their siblings.

A campaign for MLD to be added to the heel prick screening test given to all newborns is underway. This will allow for rapid diagnosis of the condition before damage can accumulate, and more lives can be saved with Libmeldy. All the families express how they are so grateful that their youngest children will be able to survive this, but that it has been so difficult to come to terms with the fact that they were given this chance by their elder siblings. Moving forward, we should be striving for early diagnoses so that all affected children can be treated, rather than relying on family history.

Ultimately, to quote the very first line of the programme, this is a story of hope. Genome-editing technologies are set to revolutionise our treatment of genetic disorders and the lives of countless families. The immense success of Libmeldy has set eyes on to developing similar treatments for other single-gene disorders.

This programme hits particularly close to home at the moment considering the current NHS crisis and fears for its future. Libmeldy is the second most expensive drug in the world with a commercial price tag of nearly £3 million, an unimaginable price for any family. A special undisclosed discount for the NHS has made it accessible to patients in the UK, which will and has already saved lives. It is an ode to our health service, and a reminder that it has never been more important to support it.