How developing a treatment for a rare disease could lead to therapies for other, not-so-rare conditions

Logan Lacy, a child with AADC Deficiency: Photo courtesy Chambersburg Public Opinion

Tomorrow, the last day in February, is Rare Disease Day. It’s a day dedicated to raising awareness about rare diseases and the impact they have on patients and their families.

But the truth is rare diseases are not so rare. There are around 7,000 diseases that affect fewer than 200,000 Americans at any given time. In fact, it’s estimated that around one in 20 people will live with a rare disease at some point in their lives. Many may die from it.

This blog is about one man’s work to find a cure for one of those rare diseases, and how that could lead to a therapy for something that affects many millions of people around the world.

Dr. Krystof Bankiewicz; Photo courtesy Ohio State Medical Center

Dr. Krystof Bankiewicz is a brain surgeon at U.C. San Francisco and The Ohio State University. He is also the President and CEO at Brain Neurotherapy Bio and a world expert in delivering gene and other therapies to the brain. More than 20 years ago, he began trying to develop a treatment for Parkinson’s disease by looking at a gene responsible for AADC enzyme production, which plays an important role in the brain and central nervous system.  AADC is critical for the formation of serotonin and dopamine, chemicals that transmit signals between nerve cells, the latter of which plays a role in the development of Parkinson’s disease.

While studying the AADC enzyme, Dr. Bankiewicz learned of an extremely rare disorder where children lack the AADC enzyme that is critical for their development.  This condition significantly inhibits communication between the brain and the rest of the body, leading to extremely limited mobility, muscle spasms, and problems with overall bodily functions.  As a result of this, AADC deficient children require lifelong care, and particularly severe cases can lead to death in the first ten years of life.

“These children can’t speak. They have no muscle control, so they can’t do fundamental things such as walking, supporting their neck or lifting their arms,” says Dr. Bankiewicz. “They have involuntary movements, experience tremendously painful spasms almost like epileptic seizures. They can’t feed themselves and have to be fed through a tube in their stomach.”

So, Dr. Bankiewicz, building on his understanding of the gene that encodes AADC, developed an experimental approach to deliver a normal copy, injected directly into the midbrain, the area responsible for dopamine production. The DDC gene was inserted into a virus that acted as a kind of transport, carrying the gene into neurons, the brain cells affected by the condition. It was hoped that once inside, the gene would allow the body to produce the AADC enzyme and, in turn, enable it to produce its own dopamine .

And that’s exactly what happened.

“It’s unbelievable. In the first treated patients their motor system is dramatically improved, they are able to better control their movements, they can eat, they can sleep well. These are tremendous benefits. We have been following these children for almost three years post-treatment, and the progression we see doesn’t stop, it keeps going and we see these children keep on improving. Now they are able to get physical therapy to help them. Some are even able to go to school.”

For Dr. Bankiewicz this has been decades in the making, but that only makes it all the more gratifying: “This doesn’t happen very often in your lifetime, to be able to use all your professional experience and education to help people and see the impact it has on people’s lives.”

So far he has treated 20 patients from the US, UK and all over the world.

But he is far from finished.

Already the therapy has been given Orphan Drug Designation and Regenerative Medicine Advanced Therapy designation by the US Food and Drug Administration. The former is a kind of financial incentive to companies to develop drugs for rare diseases. The latter gives therapies that are proving to be both safe and effective, an accelerated path to approval for wider use. Dr. Bankiewicz hopes that will help them raise the funds needed to treat children with this rare condition.  “We want to make this affordable for families. We are not in this to make a profit; we want to get foundations and maybe even pharmaceutical companies to help us treat the kids, so they don’t have to cover the full costs themselves.”

CIRM has not funded any of this work, but the data and results from this research were important factors in our Board awarding Dr. Bankiewicz more than $5.5 million to begin a clinical trial for Parkinson’s disease. Dr. Bankiewicz is using a similar approach in that work to the one he has shown can help children with AADC deficiency.

While AADC deficiency may only affect a few hundred children worldwide, it’s estimated that Parkinson’s affects more than ten million people; one million of those in the US alone.  Developing this gene therapy technique in a rare disease, therefore, may ultimately benefit large populations of patients.

So, on this Rare Disease Day, we celebrate Dr. Bankiewicz and others whose compassion and commitment to finding treatments to help those battling rare conditions are helping change the world, one patient at a time.

You can follow the story of one child treated by Dr. Bankiewicz here.