Sometimes it can be difficult to find or afford certain medications designed for your condition. However, this may soon be changing for Canadians with spinal muscular atrophy (SMA). On March 28, 2021, the Canadian Agency for Drugs and Technologies in Health (CADTH) shared new recommendations on reimbursing patients for Zolgensma (onasemnogene abeparvovec). This is the first gene therapy solution designed for patients with SMA.

Zolgensma

Licensed by Novartis Pharmaceuticals Canada Inc. (“Novartis Canada”), Zolgensma:

targets the genetic root cause of SMA by replacing the function of the missing or nonworking gene, called the SMN1 gene. This gene is critical to making SMN protein.

The treatment, administered intravenously, is indicated for patients with SMN1 balletic mutations and 1-3 copies of SMN2. Now, the CADTH has recommended that all public drug plans throughout Canada reimburse the treatment for pediatric patients. However, Quebec’s plan is not included. Recommendations and qualifications around the reimbursement include:

• Patients must be younger than 6 months old and cannot require any non-temporary ventilation or feeding support.
• To be prescribed Zolgensma, patients must be receiving treatment from an SMA specialist.
• Patients are only reimbursed for one treatment, which should last a lifetime.
• The price of Zolgensma must be reduced.

Interested in learning more about the CADTH recommendations? See the full document here.

The Reasoning

So why did the CADTH decide to make these recommendations for gene therapy and lowered pricing? Currently, Zolgensma is available as a one-time treatment for CAD $2,910,500 (approximately USD $2.3 million). However, this pricing is generally not accessible for many people. More so, Zolgensma is being compared to nusinersen, also available for SMA, but there is not a way to determine if either drug is significantly more effective in the long-term.

The recommendation came after data from a Phase 3 clinical trial which highlighted Zolgensma benefits for pediatric patients with SMA. During the trial, patients were able to hit specific motor milestones by 18 months old (1.5 years). Additionally, patients taking Zolgensma achieved better breathing and a higher quality of life (QOL).

Considering the potential benefits, alongside the financial background, the CADTH determined that new and efficacious treatments were needed. Thus, they decided to update their recommendations for Zolgensma.

Spinal Muscular Atrophy (SMA)

In most cases, SMN1 gene mutations cause spinal muscular atrophy (SMA), a rare genetic disorder. The gene mutations cause patients to lose motor neurons in the spinal cord and brain stem. Since motor neurons, a type of nerve cell, play a role in muscle development, patients develop muscle weakness and atrophy. Because of this, patients may have difficulty walking, holding their head or moving their head, crawling, swallowing, or breathing.

There are multiple subtypes of SMA, including Werdnig-Hoffman disease (type 1), type 2, Kugelberg-Welander syndrome (type 3), and type 4. In each case, the symptoms and severity vary. For example, patients with type 1 SMA are often diagnosed at or soon following birth. This form may cause difficulty swallowing or breathing, developmental delays, and inability to support the head without assistance. Type 2 develops between ages 6 months and 1 year, causing an inability to stand or walk independently. In Type 3, patients develop symptoms between childhood and adolescence, causing progressive muscle weakness and difficulty with walking or climbing stairs. Type 4 SMA often occurs in adulthood with onset after 30 years old. This form causes tremors, muscle weakness, and some breathing issues.

Some additional signs and symptoms associated with SMA include:

• Spontaneous tongue movements
• Scoliosis (abnormal spinal curvature)
• Limited mobility
• Decreased muscle tone