Spinal muscular atrophy (SMA) is a rare genetic disorder that affects muscle strength and movement. While traditional treatments aim to manage symptoms, a breakthrough, SMA gene therapy, is changing the future of care. This treatment targets the genetic root cause of SMA, offering hope for improved mobility and longer life. Especially in children diagnosed early, spinal muscular atrophy gene therapy can lead to significant, life-altering results.
In this blog, we will explore how gene therapy works for SMA, who it’s meant for, what treatments are currently available, and what challenges remain. If you’re seeking a deeper understanding of this innovative treatment, you’re in the right place.
Table of Contents
What is SMA Gene Therapy?
SMA gene therapy is a specialized treatment designed to correct the underlying genetic cause of spinal muscular atrophy. SMA happens when there’s a mutation or deletion in the SMN1 gene, which is responsible for producing a protein vital for the survival of motor neurons. Without this protein, muscles weaken over time due to nerve damage.
Gene therapy works by delivering a healthy copy of the SMN1 gene into the body using a harmless virus as a carrier. Once inside, the new gene starts producing the missing SMN protein, helping motor neurons survive and function properly. Unlike ongoing treatments, SMA gene therapy is typically given as a one-time infusion. The goal of this therapy is to stop or slow disease progression early, especially before too much nerve damage occurs. This makes early diagnosis through newborn screening extremely important.
In short, SMA gene therapy offers a way to treat the disease at its source, not just manage its symptoms.
Approved Gene Therapies and Their Impact
Currently, the most well-known and widely approved SMA gene therapy is Zolgensma (onasemnogene abeparvovec). It is a one-time gene replacement therapy approved by the FDA and several global health agencies, including India’s DCGI. It’s designed for children under 2 years of age who have a confirmed diagnosis of SMA.
It works by delivering a fully functional copy of the SMN1 gene into the body using a harmless viral vector (AAV9). This restored gene allows the body to produce the SMN protein that’s critical for motor neuron survival, which SMA patients otherwise lack.
Is Spinraza or Evrysdi Also Gene Therapy?
A common confusion among people is whether Spinraza and Evrysdi are also gene therapies. Though they are approved treatments for SMA, they are not gene therapies.
Neither Spinraza nor Evrysdi fixes the root cause of SMA. Instead, they help the backup SMN2 gene produce more of the missing protein. These are ongoing treatments, not one-time solutions.
How Spinal Muscular Atrophy Gene Therapy Works?
Spinal muscular atrophy gene therapy uses advanced genetic science to deliver what the body is missing: the SMN1 gene. Here’s how it works, step by step:
1. Gene Delivery Using a Viral Vector
A harmless virus, usually AAV9 (adeno-associated virus 9), is used to carry the functional SMN1 gene. This virus is chosen because it can safely enter nerve cells without causing disease.
2. One-Time Intravenous Infusion
The therapy is given as a single IV dose, usually in a hospital setting. Once inside the bloodstream, the viral vector travels to the motor neurons.
3. SMN1 Gene Activation
Once it reaches the nerve cells, the SMN1 gene starts functioning. It begins to produce the SMN protein, which is essential for the survival and health of motor neurons.
4. Motor Neuron Support and Muscle Improvement
With the SMN protein being made, motor neurons begin to stabilize. This can improve muscle strength, slow disease progression, and even reverse some symptoms if caught early.
5. Lifelong Impact with a Single Dose
The gene doesn’t integrate into the DNA but stays in the nerve cells for a long time. This is why a single infusion can offer long-lasting results, especially in infants and young children.
SMA gene therapy is most effective when given early, ideally before major muscle damage occurs. That’s why many experts advocate for newborn screening and early intervention.
Benefits and Limitations of SMA Gene Therapy
SMA gene therapy, especially through Zolgensma, has been hailed as a revolutionary step in treating spinal muscular atrophy. But like any advanced treatment, it comes with both advantages and important limitations.
Benefits of SMA Gene Therapy
1. One-Time Treatment
Unlike other therapies requiring lifelong doses, Zolgensma is a single intravenous infusion designed to deliver lasting results.
2. Targets the Root Cause
It replaces the faulty SMN1 gene, addressing the underlying cause of SMA rather than just managing symptoms.
3. Improved Motor Function
Many children treated early have reached milestones like sitting, crawling, or even walking, often impossible without treatment.
4. Extended Life Expectancy
For severe cases like SMA Type 1, Zolgensma has significantly increased SMA life expectancy, especially when given before symptom onset.
5. No Need for Spinal Injections or Daily Doses
This eliminates the burden and potential complications of repeated procedures, especially in infants.
Limitations and Challenges
1. Age Restriction
Currently, Zolgensma is approved for children under 2 years, which limits access for older patients and adults.
2. High Cost
Zolgensma is known as one of the world’s most expensive treatments, priced at over ₹16 crore (USD $2.1 million). Insurance coverage is often limited, especially in developing countries.
3. Availability Issues
Not widely available in all countries, including India, where access is still limited to select hospitals or private arrangements.
4. Not a Cure for All
While it can halt progression and improve quality of life, it cannot reverse all existing damage, especially if motor neurons are already lost.
Cost and Availability
Zolgensma, the only approved spinal muscular atrophy gene therapy, is currently one of the most expensive treatments in the world, priced at:
The SMA injection cost is approximately ₹16 –18 crore in India and about $2.1 million globally.
This high cost is due to:
- Complex gene manufacturing processes
- Advanced delivery methods
- Single-dose, potentially life-altering impact
While the value of the therapy is undeniable, the price makes it inaccessible for many without financial aid.
Is SMA Gene Therapy Available in India and Worldwide?
India: Zolgensma is available, but only in select private hospitals. It’s not yet part of most government health schemes or insurance plans.
Global: It is approved in over 40 countries, including the USA, UK, Japan, and EU nations.
You can access the treatment in the following ways:
- Compassionate use programs
- Medical crowdfunding like ImpactGuru (common in India)
- NGO and pharma-backed assistance
- Private insurance (where available)
Financial Aid and Fundraising
Because of the extreme cost, many Indian families turn to:
- Medical crowdfunding platforms (like ImpactGuru)
- Corporate CSR donations
- Global grants or compassionate programs
- Some success stories show that, with community help, families have managed to raise the entire amount needed for gene therapy.
In short, while spinal muscular atrophy gene therapy like Zolgensma is medically advanced, affordability and accessibility remain ongoing challenges, especially in low- and middle-income countries.
Conclusion
SMA gene therapy marks a groundbreaking shift in the treatment of spinal muscular atrophy, offering a one-time solution that targets the condition at its genetic root. With therapies like Zolgensma, many children diagnosed with SMA now have a chance at longer, healthier lives, something that wasn’t possible just a few years ago.
However, from high costs to limited access in countries like India, the reality of spinal muscular atrophy gene therapy is both hopeful and challenging. Platforms like ImpactGuru can help you raise funds for this costliest gene therapy. Early diagnosis, awareness, and improved healthcare policies are crucial to making this life-changing treatment accessible to all who need it.
FAQs
1. Why is Zolgensma so expensive?
Zolgensma is expensive because it’s a one-time, life-changing gene therapy that involves complex development, manufacturing, and delivery processes. It uses advanced viral vector technology to deliver a functional SMN1 gene, and the cost also reflects years of research, limited patient population, and the potential for long-term benefit from a single dose.
2. Is Zolgensma approved in India?
Yes, Zolgensma is approved in India by the Drugs Controller General of India (DCGI). However, it is not yet widely available through public healthcare systems or insurance. Access is generally limited to private hospitals, and most families rely on crowdfunding or international aid to afford the treatment.
3. What is the Zolgensma gene therapy success rate?
Zolgensma has shown high success rates, especially in infants treated early. Clinical trials and follow-up studies report that most children reach key motor milestones, such as sitting, crawling, or walking, and survive longer without permanent ventilation. Its success is highest when administered before symptoms progress.
