Karanveer was like any other child when he was born. As he grew up, he seemed fine. But from a very young age, he began to walk on his toes or the balls of his feet with a waddling gait. He had trouble climbing stairs, getting up from the floor and even running.
When he was about four years old, he was diagnosed with Duchenne Muscular Dystrophy (DMD), a Neuro-degenerative disorder.
DMD, a rare disease, occurs only in boys and is a condition where a protein called Dystrophin, which is needed for the proper functioning of the muscles is present in much lower levels than required. And as the boy grows up, muscles continue to degenerate.
In simple terms, it means that the child will be wheelchair-bound for most of his life before he becomes bed ridden.
There is no cure for DMD.
The only way to manage it is through steroids and physiotherapy.
For Karan’s father, RS Anand, this was no deterrent. He decided to find a solution to this rare disease and spent several years understanding the pathology of the disorder, the extent of research investment and the mechanisms for optimal care.
His obsession with finding a cure for his son led him to start the Dystrophy Annihilation Research Trust (DART) in 2012. He set up an R&D lab, brought in the necessary equipment and began to try and find a cure for DMD. He roped in Dr. Arun Shastry to lead this research.
Karanveer with his family
There are several trials happening in countries like US, UK and Australia. Some research centres are even running clinical trials. But in India, nothing has been done to treat or find a cure for DMD. India has more than half a million boys suffering from DMD.
The complication with DMD is that being genetic, no two children are the same. Hence the treatment for every child is unique. “A personalized medicine has to be developed for each child, which means extremely high costs, even for research. This is why no one has taken it up,” Arun says.
Finding a cure
The technology that DART is focusing on to find a treatment for DMD is called ‘exon skipping’.
DMD is a genetic disorder. A gene is a section of DNA that contains the instructions for the production of one specific protein. Proteins are essential parts of cells and play a role in every process occurring within the cell, as well as having structural or mechanical functions which help maintain the cells’ shape. It is estimated that we have about 25,000 different genes
Genes are divided into sections called ‘exons’ and ‘introns’. Exons are the sections of DNA that code for the protein. The dystrophin gene is our largest gene - it has 79 exons which are joined together like the pieces of a puzzle.
Imagine a necklace with 79 pearls, and strung together, the necklace – the dystrophin gene – performs the function of producing the vital proteins for our body.
When a boy is afflicted with Duchenne muscular dystrophy, some of the pearls – the exons - go missing. As a result, the entire pearl necklace falls apart, and the dystrophin gene cannot perform its function. This leads to several malfunctions in the body.
How can exon-skipping help?
So how do you mend a pearl necklace with a pearl missing? You tie the two broken ends of the necklace together, and skip the missing pearl. That is the principle used in exon skipping.
The principle of exon skipping is to encourage the cellular machinery to ‘skip over’ an exon. Small pieces of DNA called antisense oligonucleotides (AONs) or ‘molecular patches’ are used to mask the exon that you want to skip, so that it is ignored during protein production.
The challenge is, for each child’s gene, a different exon could be missing. DART takes cells from affected children, tries to find out where exactly the defect is, and patches it up there to restore protein production.
Arun learnt this technique under Australian scientist Steve Wilton, touted to be the pioneer in this field. Once he learnt the technique, DART bought the required equipment, oligonucleotides synthesizer, which produces the required antisense oligonucleotides.
“We have a fully automated process. We just have to feed the sequence in and the required DNA is printed out. We can now design, synthesize and screen the drug and show the proof of concept. We currently have nearly 20 children who have registered with us and we have cell lines from all of them and have done proof of concept in our labs for all those kids,” Arun says.
However, before DART can test out the proof of concept on the children or run clinical trials, it needs to first do required toxicity tests for which it has outsourced it to companies to carry out animal testing of this drug.
But Arun is confident that this will work in treating children with DMD.
“Clinical trials abroad have shown that this can work. We are not reinventing the wheel. We have just taken the same technology being worked on abroad and modified it,” he says.
A similar drug that got approved in the US, Arun says is based on a chemistry which cannot be scaled up in a machine. It has to be handmade, which is very labor-intensive. As a result, the price for this in the US is currently $300,000 per year per child.
However, using technology to produce this drug, DART’s target is to make a drug that is at least $10,000 per year per child.
Since the technology developed by DART is just feeding formula and printing the drug out, the machine can make from 1ml to 100 grams, and it takes the same amount of time for both, claims Arun. This makes their drug a lot more scalable.
Dr. Arun Shastry
Another modification done by DART is modifying the chemistry in a way that the drug is targeted directly to the cell. This makes it a lot more effective at a low dosage.
With their drug showing signs of success, DART, being an NGO, makes it complicated for the drug to be commercialized. Hence, in February 2017, Hanugen Therapeutics Private Limited was launched by the members of DART for the commercial production of Antisense Oligonucleotides for the therapy of genetic disorders, especially Rare Diseases.
With toxicity tests currently underway, Hanugen hopes to receive the tests soon, receive required approvals and start clinical trials by the end of this year.
The biggest advantage with the technology that they have built and the equipment being used is that it can be applied to other genetic diseases as well.
Hanugen will eventually also start working on other rare diseases as well.
Not just DMD
There are several other types of dystrophy. Arun says there is scope for exon skipping to work on conditions like Spinal muscular dystrophy as well.
“We have set up a platform. There are other conditions where you can silence the gene as well like for example in cancer or diabetes. There is scope to make at least 10 different drugs using this machine,” says Arun.
The challenge currently for DART or even Hanugen is funding the research. There is a lot to be done, but rare diseases are not given enough attention in the country.
But Arun says this doesn’t stop them from finding a cure for these rare diseases. “We see the target and are working towards it. If required, we beg, borrow but we don’t stop our work,” Arun says.