Spinal muscular atrophy (SMA) is a rare neuromuscular genetic disease that, in its most common form, is fatal in early childhood. Approved in May 2019, onasemnogene abeparvovec-xioi (Zolgensma^®) became the only one-time gene therapy for SMA treatment in patients less than 2 years of age with a cost of more than $2.1 million. At the time of U.S. Food and Drug Administration (FDA) approval, there was only high-quality, managed care data on 25 patients treated with Zolgensma therapy. 

In this study, researchers sought to describe real-world SMA non-gene drug treatment and SMA disease-related outcomes in a group of members treated with Zolgensma. 
 
This case series, including descriptive analysis of 52 members treated with Zolgensma with a 15-month median follow-up (range 1 month to 56 months), found no evidence of death or hospice. The average age at gene treatment was 7.2 months and decreased across the study period from 21 months to less than 2 months, which may be due to increased newborn screening. In June 2021, 34 states offered SMA newborn screening, and all 50 states offered screening by January 2024. 
 
Non-gene therapy, risdiplam (Evrysdi^®) or nusinersen (Spinraza^®), was initiated in 1 out of 26 of those treated with Zolgensma. Experts expected to avoid the cost, at more than $300,000 annually, after Zolgensma treatment. Future Evrysdi or Spinraza use after Zolgensma therapy requires further investigation, as minimal clinical evidence supports this treatment with substantial added cost. 
 
These findings can aid in the development of evidence-based coverage decisions, understanding risk for future non-gene disease modifying therapy and pharmaceutical manufacturer value-based contract negotiations. 

I (Alex Cook, part of the Prime newsroom team)connected with Scott Leslie, director of health outcomes at Prime, and lead author on this study to learn more about the study and its implications.

Alex Cook: At AMCP Nexus last year, Yuqian Liu, senior director of specialty clinical solutions, presented a session “Improving Treatment Access for Spinal Muscular Atrophy: How Managed Care Strategies Can Ease Clinical Caregiver Burden.” It was a striking presentation, in part because of how serious SMA can be among affected children but also how effectively it can be treated with these radical therapies. What surprised you most about this study?
Scott Leslie: Yuqian Liu’s presentation was highly informative to the managed care pharmacy audience. She described existing FDA-approved SMA treatments and their cost-effectiveness, plus highlighted the importance of early and effective treatment and provided recommendations to managed care professionals. Our observational study identified 52 members less than 2 years of age receiving the only gene therapy, onasemnogene abeparvovec-xioi (Zolgensma) treatment for SMA. We observed two members receiving non-gene therapy after gene treatment and seven members with medical claims indicating respirator dependence and chronic respiratory failure. This finding indicates that although treatment advancements have brought hope to these children and their families, there remains challenges to SMA treatment.

Specialty care is a growing segment of Prime’s business, and it certainly seems to be garnering more attention among researchers at AMCP. What are some things that managed care professionals can learn from this study?
Our findings can aid in the development of evidence-based coverage decisions, in understanding risk for future non-gene disease modifying therapy and in negotiating pharmaceutical manufacturer value-based contracts.

Some health care providers may be reluctant to work with managed care pharmacy professionals, but what does this study show us about the important role they can play in the treatment of disease?
Our study highlights the value that managed care pharmacy professionals can add in evaluating the effectiveness of gene therapy treatments by describing use and outcomes outside of clinical trial data.

How might this study inform future research of SMA?
Our study describing real-world data on SMA treatment among a large nationally representative sample, 1.5 million Medicaid and 16.5 million commercially insured members, provides information that can help further research on outcomes associated with age at treatment and use of non-gene treatments before and after Zolgensma infusion.

Stay tuned for more AMCP Nexus 2024 in focus content throughout the week in the Prime newsroom. For more information on this research, check out the research poster.