What is the recommended treatment plan for an 11-year-old female patient with spinal muscular atrophy type 2 and sleep apnea, who is currently receiving Spinraza (nusinersen) and participating in a clinical trial for human anti-Promyostatin monoclonal antibody infusion?

Recommended Treatment Plan for 11-Year-Old with SMA Type 2

Continue Spinraza (nusinersen) 12mg intrathecal every 4 months as the primary disease-modifying therapy, resume the delayed dose immediately, and maintain CPAP therapy for sleep apnea management. 1

Primary Disease-Modifying Therapy

Nusinersen (Spinraza) should be continued as scheduled based on moderate-certainty evidence demonstrating significant motor function improvement in SMA type II patients, with a 3.7-point improvement on the Hammersmith Functional Motor Scale Expanded (HFMSE) compared to a 1.9-point decline in untreated patients. 1

• Resume the delayed dose immediately - the patient's last infusion was several months ago due to insurance changes, and maintaining the every-4-month dosing schedule is critical for sustained benefit. 2
• The standard maintenance dose of 12mg intrathecal every 4 months is appropriate for her current weight of 49.1 kg. 2
• Given her spinal fusion history, coordinate with interventional radiology or neurosurgery for intrathecal access planning, as 100% technical success has been achieved in complex SMA patients with spinal instrumentation using alternative approaches including neural-foraminal technique (L3-L5) or cervical puncture when standard interspinous approach is not feasible. 3, 4

Sleep Apnea Management

Continue CPAP therapy with close monitoring given her reported increase in morning sleepiness, which suggests inadequate control of sleep apnea. 5

• The American Thoracic Society specifically identifies children with spinal muscular atrophy as candidates for CPAP therapy, though facial growth concerns exist with prolonged use (>10 hours/day), particularly maxillary retrusion in 37% of patients with neuromuscular disease. 5
• Schedule polysomnography to reassess CPAP settings given new symptoms of increased morning sleepiness despite denying daytime sleepiness or naps. 5
• Ensure regular mask refitting as she grows, as proper fit is essential for efficacy and adherence. 5
• Monitor for facial growth abnormalities given her age and prolonged CPAP requirement, though treatment benefits outweigh risks in neuromuscular patients. 5

Clinical Trial Participation

Continue the anti-Promyostatin monoclonal antibody clinical trial in combination with Spinraza, as combination therapy may provide additive benefits, though acknowledge the recent regression noted in repeat evaluation. 1

• The regression may reflect natural disease progression rather than treatment failure, as SMA type II is characterized by progressive weakness. 1
• Clinical trial participation provides access to potentially beneficial investigational therapies while maintaining standard-of-care nusinersen treatment. 1

Vitamin D Supplementation

Initiate vitamin D 1000 IU daily as recommended in the assessment/plan to address bone health, which is particularly important given her non-ambulatory status and increased fracture risk. 5

Physical Therapy Intensification

Increase physical therapy focus on passive stretching and positioning to address the documented increase in hip tightness, hamstring contractures, and knee flexion contractures that are limiting her mobility and sitting tolerance. 6

• The regression in her left upper extremity function (RULM score decreased from 25 to 21) and inability to maintain trunk control requires immediate intervention. 6
• Implement daily prone positioning to prevent further hip and knee contractures, as she no longer uses her stander post-spinal fusion. 6
• Passive stretching in prone position, knee extension stretches while sitting, and trunk stabilization exercises should be performed during sedentary activities to improve compliance. 6
• Address the documented lack of motivation for home exercise programs by integrating therapy into daily activities she enjoys. 6

Multidisciplinary Coordination

Proceed with the planned multidisciplinary meeting involving neurology, pulmonology, orthopedics, physical therapy, and occupational therapy to coordinate comprehensive care. 5

• This collaborative approach is essential for managing complex SMA patients with multiple comorbidities including sleep apnea, spinal fusion, and progressive weakness. 5
• Ensure all specialists are aware of her delayed Spinraza dosing and recent functional regression to optimize coordinated interventions. 1

Monitoring Plan

• Follow-up in 6 months as planned, but consider earlier reassessment (3-4 months) if functional decline continues after resuming Spinraza. 1
• Monitor motor function using standardized scales (HFMSE, RULM) at each visit to objectively track treatment response. 1
• Reassess sleep apnea symptoms and CPAP adherence at each visit given the new morning sleepiness. 5
• Continue monitoring for adverse events from nusinersen, which are typically mild and include headache, back pain, and post-lumbar puncture syndrome. 2