Until 2016 spinal muscular atrophy was a disease to which there was no cure or any approved treatment. Since 23 December 2016 (USA) and 30 May 2017 (European Union), there is an effective treatment to SMA: Spinraza. Additionally, a few other compounds remain in development.
Spinraza®is the first approved medicine for spinal muscular atrophy and the only one approved outside of the US. It contains nusinersen, an antisense oligonucleotide whose main function is to repair the damaged SMN2 gene. After modification with nusinersen, the SMN2 gene starts producing high amounts of the SMN protein whose deficiency is the root cause of SMA symptoms.
Spinraza did wonders in the many clinical trials that were carried in the last years as well as afterwards in normal therapeutic usage. Not only did it stop the progression of the disease but many children and adults who were treated with the drug regained strength and muscle function.
Spinraza is administered to the spinal cavity via lumbar puncture. It must be taken every four months, with an exception of the initial phase of treatment when additional three doses have to be taken over the timespan of four weeks. Treatment must continue for life or until a newer drug becomes available.Spinraza was approved for treatment of the entire spectrum of spinal muscular atrophy across the European Union on 30 May 2017. Since then it became a standard treatment in several countries. But it is still not available in India.
The current price for Spinraza is $750,000 (Rs 5crores) for the first year and $375,000 (Rs 3 crores) for every year after for the life of the patient. It is approved for all forms of SMA, types 0 through 5.
Zolgensma® is the only approved gene therapy for spinal muscular atrophy. It consists of an artificial SMN1 gene that is loaded into a specially prepared virus. The virus is injected in the veins or the spinal cavity where it “infects” the target cells with a functional copy of the SMN1 gene. The therapy has been developed by a US company AveXis (now a subsidiary of Novartis). It has been approved for use in the United States on 24th May 2019 in children with SMA under 2 years, while approvals elsewhere in the world are pending.
A single dose of AVXS-101 contains trillions of specially crafted viral particles that carry a synthetic SMN1 sequence (a transgene) inside a typical viral shell (capsid). Upon administration, these modified viruses “infect” neuronal cells with the SMN1 transgene. The transgene then starts working within the cell to produce fair amounts of SMN protein exactly the way a natural SMN1 gene would. In this way, AVXS-101 addresses the root cause of spinal muscular atrophy, that is the deficiency of SMN protein.
Novartis, set the price at $2.1 million (Rs 15crores), the most expensive drug ever.
Evrysdi, previously known as risdiplam, is cleared to treat all SMA patients aged two months or older, regardless of the severity or type of the devastating neuromuscular condition. Evrysdi was approved by the U.S. Food and Drug Administration (FDA) on Aug. 7, 2020, becoming the third disease-modifying treatment for SMA available within four years.
Roche priced the drug by patient weight, with a maximum cost of $340,000 per year. It is marketed by Roche and Genentech (a member of the Roche Group), which developed it in collaboration with PTC Therapeutics and the SMA Foundation. Evrysdi works by addressing the underlying cause of SMA: a reduced amount of survival motor neuron (SMN) protein. In SMN2, this splicing event results in the exclusion of exon 7 from most mRNA molecules this gene produces, resulting in the shorter, less stable, and poorly working SMN protein this gene produces. By correcting SMN2’s splicing, Evrysdi prevents exon 7 from being removed from its mRNA to “restore” the production of more functional SMN protein. Evrysdi (risdiplam) is an oral daily therapy for people ages 2 months and older with all types of spinal muscular atrophy.
Cure SMA India is extensively working towards making these drugs accessible in India with the help of government support.