SMA Treatment and Screening Programs ‘Essential’ in Pandemic, Panel Says
Continuing treatment for spinal muscular atrophy (SMA) is essential and should not be considered elective, or be delayed or interrupted if possible, despite the healthcare limitations imposed by the COVID-19 pandemic.
These are the main recommendations given unanimously by a panel of 15 neuromuscular specialists with expertise in SMA from across the U.S. and Europe.
These experts also “emphasize that treatment decisions should be individualized and made cohesively between the patient, family, and healthcare provider, taking into account any geographic‐ or institution‐specific policies and precautions for COVID‐19.”
Their consensus opinion was published in the journal Muscle & Nerve, in a piece titled, “Spinal muscular atrophy care in the COVID‐19 pandemic era.”
Social distancing directives to avoid the current coronavirus has resulted in a reorganization of healthcare settings affecting the care of people with SMA. Although urgent care is being provided in hospitals and clinics, non-urgent care and elective services are either being rescheduled or provided by telehealth.
While Spinraza (nusinersen, developed by Biogen) and Zolgensma (initially developed by AveXis, now part of Novartis) “are life-altering” SMA therapies that markedly improve survival and motor function, they are not cures, the panelists noted. Patients can also have “substantial” co-existing conditions, especially young children with the infantile-onset SMA, requiring regular, continuing care.
“Surging COVID‐19 rates are placing a tremendous burden on the healthcare system and healthcare providers,” they wrote. “In some instances, this has interfered with planned treatments for SMA patients. SMA treatments are critical to the health and well‐being of these patients and should not be perceived as elective or nonurgent.”
These experts first looked at Spinraza, an intrathecal (spinal canal) injection therapy given every four months after an initial, four-dose loading period spanning two months. According to its approval label, a delayed or missed initial dose should be administered as soon as possible with at least 14 days between doses, while a missed or delayed maintenance dose should also be given as soon as possible, then continued as prescribed.
The opinion piece noted, based on information shared by Biogen, that a regular maintenance dosing schedule (every four months) is crucial for maintaining high levels of Spinraza in the cerebrospinal fluid (CSF, the liquid that surrounds the brain and spinal cord), which correlates with the greatest improvements in motor abilities.
Based on modeling studies, a one-time delay of one month resulted in about a 10% decrease in CSF levels of Spinraza. A quick return to a regular treatment schedule restores these levels.
“If a patient misses a dose at 4 months and instead receives it at 6 months, the subsequent dose of nusinersen would be given 2 months later as originally scheduled and the CSF steady state exposure is restored,” the experts wrote. “If, instead, the original dosing timeline is altered, and the subsequent dose is given 4 months after the delayed dose, there is a prolonged delay to restore CSF steady state exposure.
“Every effort should be made to give a missed dose of nusinersen as soon as possible, and maintain the original dosing timeline to maximize the benefit of treatment,” they added.
Zolgensma, a gene therapy given as a one-time intravenous infusion, requires “several weeks of careful outpatient management and laboratory monitoring,” as children are given corticosteroids for at least two months to reduce potential side effects.
“Patients on corticosteroids should be advised not to discontinue these unless specifically discussed with, and approved by, their treating neurologist,” the panel advised.
But it cautioned that patients treated with immunosuppressive corticosteroids and their families should be extra-vigilant in practicing social distancing.
Changes to a Zolgensma patient’s monitoring schedule — which includes liver function, troponin complex (a skeletal and cardiac muscle protein) and blood platelet count checks — also should follow a neurologist’s advice, but alternate measures such as drawing blood at home or telemedicine visits should be considered to lessen exposure risk.
Regular physical therapy assessments, most insurance providers for treatment, should be deferred or done to the extent possible via telemedicine, the panel advised.
“We recommend that coverage for nusinersen and onasemnogene abeparvovec‐xioi [Zolgensma] should be provided without interruption even if formal clinical and physical therapy assessments are limited,” it added.
The impact of the COVID-19 pandemic on SMA newborn screening programs to identify pre-symptomatic cases is unclear, especially with limitations in face-to-face assessments and blood draws.
Regardless, the panel recommended “urgent evaluation” and “rapid” treatment initiation of infants with SMA identified through such programs, “while following the regional and institutional policies pertaining to the public health emergency and maximizing the safety of patients and caregivers.”
SMA healthcare teams should work together to avoid treatment delays, as early and uninterrupted treatment leads to better outcomes, especially for newborns and infants with SMA.
“We recommend strict adherence to established policies pertaining to the COVID-19 response and recommend that healthcare providers work … to ensure timely and uninterrupted care for patients with SMA taking into account the potential risks of COVID-19 exposure,” the panel concluded.