Subsequent treatment after gene therapy in spinal muscular atrophy provides additional benefit when motor scales had initially plateaued.


Clinical Management

Poster Number: S106


Stephanie Acord, MD, Cook Children's Medical Center

Spinal muscular atrophy is a progressive neuromuscular disorder that has seen many new treatments become commercially available since 2016. Unfortunately, the accessibility to multiple treatment options based on sub optimal response lies in the hands of the insurance
companies, not the treating providers and the patient’s family. We as treating providers have contemplated when to try to add a second treatment when our patient has not had the response we were hoping for. At this time, we are unable to predict which patients will respond the best to the treatments. Here we share our real world experience of treating seven patients with spinal muscular atrophy that received onasemnogene abeparvovec(zolgensma) initially and had
the addition of either nusinersen or risdiplam based on a suboptimal response. Six of the seven patients have 2 copies of SMN2 and one patient has 3 copies of the SMN2 gene. All patients were felt to plateau in the motor function gains prior to initiation of subsequent treatment. The improvement on first subsequent CHOP INTEND after initiation of treatment for the type 1 patients ranged from 3 points in 1 month to 16 points in 5 months. The type 2 patient has
improved by 3 points on Revised Hammersmith Scale in less than 3 months. The fast and robust improvement in these scores were felt to be strictly from additional treatment and not misinterpreted as a continued improvement from the initial zolgensma treatment. These
patients have continue to make additional gains in clinical examination assessments, motor development scales, motor milestones, and quality of life. Secondary treatments have not been found to be associated with any adverse events thus far in our patients. Based on our experience, we feel that all patients with spinal muscular atrophy should have accessibility to additional treatments to promote additional gains.