Evaluating Novel Gene Therapy Options for Spinal Muscular Atrophy
Cincinnati Children’s began offering the gene therapy drugs Spinraza and Zolgensma for spinal muscular atrophy (SMA) almost as soon as the Food and Drug Administration approved them. Since then, Cuixia Tian, MD, has responded to many inquiries from other pediatric neurologists seeking information about her team’s comprehensive approach to administering these therapies. She says she’s happy to help others navigate the challenges and pitfalls — especially since treatment is often effective in improving patients’ quality of life.
“Spinraza and Zolgensma are the first gene therapies approved for pediatric neuromuscular disease, and most of our center’s 60 SMA patients are receiving one or the other,” explains Tian, who is co-director of the Comprehensive Neuromuscular Center at Cincinnati Children’s. “Neurologists, pharmacists, interventional radiologists, nurses, physical therapists, preauthorization team members and many others work together to ensure that we deliver these therapies as safely and effectively as possible.”
Spinraza: Close Monitoring Required
Children with SMA are missing the survival motor neuron 1 (SMN1) gene, which produces a protein that is critical to the nerve function that controls muscle activity. Spinraza, which was approved in 2016, increases the ability of cells to produce functional SMN protein from the SMN2 gene. About 40 Cincinnati Children’s patients receive this therapy, which is delivered via lumbar puncture. Patients receive four doses in the first two months, and then a dose every four months for life; each dose costs approximately $125,000. Patients must be monitored closely throughout the course of treatment.
While Spinraza is not a cure for SMA, it can improve life quality significantly, Tian says. She points to a child with SMA Type 1 who was previously bedridden and can now sit up independently. A child with SMA Type 2 who was not able to stand is now taking steps without assistance. Tian and her team recently presented data at a regional Cure SMA meeting demonstrating a correlation between improved function and quality of life scores.
Zolgensma: A One-Time, $2.1 Million Therapy
Zolgensma, which was approved for patients under 2 years of age in May 2019, is a one-time therapy that delivers the deleted gene intravenously. It uses a virus vector, which necessitates one to two months of steroid to pretreat potential immune response complications. This requires diligence, but by far the most challenging aspect of providing Zolgensma is its cost: $2.1 million per dose. Confirming insurance coverage involves a long process of preauthorization and appeal.
“The price for this drug is high, but many drugs exceed that cost when they are given indefinitely,” says Eileen Broomall, MD, a pediatric neurologist at Cincinnati Children’s. “The long-term savings are there if these patients can grow healthily and don’t need invasive ventilation.”
So far, two patients have received Zolgensma at Cincinnati Children’s. One of the patients was diagnosed with a newborn screening. That patient was asymptomatic at the time of treatment and now is meeting age-appropriate milestones. The other patient, treated at 7 months, was quite symptomatic when treated, but has shown improvement as well.
“My hope is that all states offer newborn screening for SMA and that every child with SMN1 gene deletions is diagnosed before becoming symptomatic,” Broomall says. “This can lead to more effective treatment and better outcomes.”
Learn more about the Comprehensive Neuromuscular Center at Cincinnati Children’s.
(Published July 2020)
