What is Zolgensma?

It is an FDA-approved drug which is basically a type of gene replacement therapy used to treat spinal muscular atrophy(SMA) in paediatric patients. A single dose of this drug can provide a lifetime of benefit and save lives. The drug’s original developer is Avexis which has been acquired by Novartis in May 2018.

What is Spinal Muscular Atrophy (SMA)?

SMA is rare hereditary disease which is caused due to a missing gene (SMN1). This is a functional survival motor neurone 1 gene therefore its deficiency leads to rapid loss of motor neurons which in turn deteriorates body’s normal functions like breathing, swallowing and movement. It could result in paralysis. SMA is a major genetic cause of fatalities in infants. 

How does Zolgensma work?

The main objective of this drug is to replace the abnormal SMA gene with a normal gene. So it uses genetically engineered viruses in order to rise the SMN protein levels in the individual that are missing in the case of spinal muscular atrophy.

When the viruses enter our body, our immune system starts to produce antibodies against it. But several copies of the virus are successfully able to reach various cells of the body and make the required SMN protein. 

How is Zolgensma administered?

It is administered into the bloodstream of the patient via injection. However Novartis tried conducting clinical trials to see if the drug can be given directly into the fluid bathing the spinal cord and brain for patients older than 2 years of age. The trials are currently on hold and a conclusion is awaited. 

Also read : INDIA’S FIRST CASE OF H5N1 AVIAN INFLUENZA IN HUMAN

Who are ineligible for the administeration?

The virus that is present in the injection is also naturally available in the environment. This brings about the possibility of a developed immunity against the virus in some children with SMA. In this case, these children become ineligible to receive the drug benefits.    

Why is Zolgensma so expensive? 

Zolgensma is the world’s costliest drug which costs around 18 crore rupees in India before GST exemption. The drug has the potential to save lives. There are various factors that went into consideration for the establishment of this exorbitant price. 

One of the major reasons is that it has a very small market size due to lesser demand. It is easier to understand from the sales perspective. As it is a drug which is very effective against a rare condition that affects 1 in 8 to 10 thousand people worldwide, the requirement or the sales are very low as compared to a normal drug so it becomes difficult for the company to generate profits and cover all the costs that goes into manufacturing by keeping a modest price tag. 

Also, when such a drug is being manufactured, it takes years of research and billions of dollars are spent in its making. Then the drug is being sent for the approval and only after that it is made available for use. 

Another factor that plays a role in this pricing could be the impact it has when compared to the available competition. The other approved drug fo the treatment of SMA is called Spinraza. It is manufactured by Biogen. As per the clinical trials, it is comparatively not as effective as Zolgensma. For the treatment of SMA it is given to the patients over a period of five years where as Zolgensma is a one time treatment and very effective for a lifetime. It not only reduces the number of years a patient has to spend for the treatment but also cuts the huge costs that a chronic illness like this demands over many years. It might be difficult to understand this when we see a price as high as this drug has but it is actually lesser than any other available treatment for the same.

All these things are considered when drugmakers set a price for a specific drug.

On 17th September, 2021 after the 45th GST Council meeting Union Finance Minister Nirmala Sitharaman announced that GST will be exempted from Zolgensma along with several other expensive drugs. 

Why does a patient cannot receive a second injection of Zolgensma?

Our body responds to any virus the same way as it does with the one present n the Zolgensma gene therapy. Once a patient’s system is exposed to the virus, antibodies will be produced and they will be able to recognise the same virus in future as the patient has now developed an immunity against it. This makes the second injection ineffective.