A new spinal muscular atrophy (SMA) drug approved in the UAE has been hailed as “a game-changer” in treatment of the condition.
As reported in The National, regulators in the Emirates have given the go-ahead for the use of Itvisma, a drug that will enable gene therapy treatment to be given to older SMA sufferers.
For several years, doctors in the UAE have successfully been administering another gene-therapy drug, Zolgensma, to children with SMA.
However, this medicine is suitable only for infants, while Itvisma, now approved by the Emirates Drug Establishment after the thumbs up in November from the US Food and Drug Administration (FDA), can be given to children older than two, as well as teenagers and adults.
Treatment is likely to come at a high cost, with Zolgensma, which works in a similar way, having been described as the most expensive drug in the world, with a price tag of $2 million per treatment.
The drug, which received FDA approval in 2019, needs to be administered only once, as does Itvisma.
Offering fresh hope
Giles Lomax, chief executive of SMA UK, a charity that supports people with the condition and works with health authorities to advance treatment, said Itvisma was “a really great step in the right direction”.
“It’s a huge game-changer for us,” he said. “Although the drug is expensive – gene therapies are expensive – over time they average themselves out.
"If children are diagnosed really early within that first 12 months, if they’re eligible they can go straight on to Zolgensma. [Itvisma] is really for those who missed that window. If you don’t quality [for Zolgensma], there’s the option for you to go on to it.”
Unlike many other neurodegenerative conditions, such as Alzheimer’s, which have proved difficult to develop drugs for, huge strides have been made in SMA treatment in recent years.
This is because most cases are caused by a mutation in a single gene, survival motor neuron 1, or SMN1, which codes for the survival motor neuron protein.
In patients with the mutation in SMN1, the motor neurons, which are nerve cells that take signals from the brain to the muscles, cannot function properly, causing weakness in the limbs.
Patients may be unable or struggle to walk, and may also have difficulty breathing or swallowing.
The most severe form of SMA, type 1, develops in the first six months of life and without treatment typically proves fatal early in life.
Children with type 2 may be unable to walk, while types 3 and 4, which affect older children and adults, also cause significant symptoms, albeit not as severe as those of types 1 and 2.
SMA is more common in the Gulf region than in other parts of the world because of the tradition of consanguineous marriage.
This makes it more likely that two adults who are SMA carriers – meaning that they carry one copy of the mutation in their genetic material but do not have the disease themselves – will marry, creating a higher risk of their children having the condition.
Gene therapy drugs, such as Itvisma and Zolgensma, replace the “defective” gene with a normal version, enabling the patient’s own cells to produce the survival motor neuron protein normally.
Boosting quality of life
In a statement released in November when FDA approval was given, Novartis, the pharmaceutical giant behind Itvisma, said the drug had achieved “statistically significant improvements in motor function and stabilisation of motor abilities” that otherwise were not seen. The effects, the company said, were sustained during follow-ups taking place over a year.
Tying in with this, Dr Ahmad Abou Tayoun, director of the Genomics Centre of Excellence at Al Jalila Children's Specialty Hospital in Dubai, which has treated many children with SMA, told The National the clinical trials for Itvisma indicated the drug “was safe and improved motor function in SMA patients”.
“Overall, the results are encouraging and suggest that gene therapy could benefit SMA patients of all ages,” he added. Dr Abou Tayoun said the new drug “extends access to gene replacement to the broader SMA population”, namely those aged above two.
As Itvisma is new it is unclear how treatment will be funded but Dr Abou Tayoun said the UAE authorities have covered the cost of treating Emirati patients with Zolgensma.
In July it was revealed that Sheikh Mohammed bin Rashid, the Vice President and Ruler of Dubai, would pay the Dh7 million ($1.9 million) needed to allow Zolgensma to be given to a young Syrian girl with SMA.
Dr Abou Tayoun has previously worked with US biotech company Asuragen on the development and optimisation of a cost-effective SMA test for newborns, which enables treatment to begin as early as possible. He and his colleagues have also developed another test able to detect many genetic variants linked to SMA.
A year ago it was announced that premarital screening for conditions including SMA was to become compulsory for Emirati couples marrying in the UAE from January 2025. Screening can indicate whether any children a couple go on to have could be at risk of developing SMA.
As well as Itvisma and Zolgensma, two other drugs have been released in recent years to combat SMA. Nusinersen, which is sold as Spinraza, received FDA approval in 2016 and Risdiplam, branded as Evrysdi, was given the go-ahead by the organisation in 2020.
Each causes a related gene, SMN2, to increase production of SMN, although multiple applications are needed at an annual cost reported to be several hundred thousand dollars.
