Q: I was wondering if you could write about some of the recent advances in pediatric medicine that have been featured in the national news?
A: In the very recent past, there have been two rather exciting innovations in pediatric medicine, addressing two very serious conditions. One is a medicine treating a condition called Spinal Muscular Atrophy Type 1 and the other is a novel treatment for a childhood cancer called leukemia.
Spinal Muscular Atrophy is a congenital condition that about 1 in 10,000 babies are born with, where a missing gene leads to profound muscle weakness.
The SMN-1 gene makes a protein that allows nerves to speak to muscles. If the gene is missing, no protein is formed and muscles do not function properly. The weakness affects all major functions, including breathing, and unfortunately is associated with early death, often by 2 years of age. There are 4 types of SMA, with Type 1 being the most severe. Brain development is normal in these children and they exhibit a startling awareness of the environment around them. They often seem to have unusually bright and expressive eyes, and interact with caregivers. Until now, treatments have been limited to supportive care through occupational therapy, physical therapy, feeding tubes and respiratory support devices.
Last fall heralded FDA approval of a medication that may offer some hope to these children and their families. This new drug works by changing the function of a gene that the children do have, the SMN-2 gene. Typically, the SMN-2 gene does not produce much of the crucial protein. But the new drug appears to change the way SMN-2 functions so that it can now produce much more of the protein, which means better communication between nerves and muscles, and ultimately stronger muscles.
Research indicates that the greatest improvement is seen when treatment is started very early, often below 7 months of age. There are not enough data currently to say how much improvement is possible or whether the effect is sustained. However, this potential treatment is really the first beacon of hope for babies with SMA-1 and their families. We will watch with great interest and hope to see what the long-term effects of the new therapy will be. There is a very inspiring patient story on the website of The Children’s Hospital Colorado.
The second recent innovation that was in the news is a drug called CAR-T, which is for children with a blood cancer called leukemia. The children eligible for this drug are those who have failed available therapies and have little hope of surviving their cancer.
The new potential treatment employs a technology called gene therapy to personalize the treatment for each patient. Some of the child’s cancerous blood cells are removed and then, through laboratory magic, a gene is inserted into those cells and programmed to destroy them. The treated cells are then reintroduced into the child’s blood, where they go on to kill the rest of the cancerous blood cells.
The potential magic of gene therapy is how specifically it targets the exact cancer of each child. However, there can be severe side effects. For children with leukemia, most of their white blood cells are affected and the destruction of so many white blood cells is very hard on the body, and can make a child very ill. It also leaves the child very immunosuppressed and vulnerable to overwhelming infection.
The first child who received this experimental treatment, five years ago, has reportedly done well. But there have been other children who suffered severe side effects and some who did not survive.
The thing to keep in mind, which some parents explained to the FDA Advisory Panel, is that children with such severe leukemia really have no other chance. The nature of this science combined with the impassioned parental support led to the Advisory Panel unanimously voting for the drug to be approved. Apparently, the FDA is not obligated to take the Panel’s recommendation, but the vote of support feels like a positive step.
Anjali Subbaswamy is a Pediatric Intensive Care Physician at UNM. Please send your questions to her at firstname.lastname@example.org.