CADTH Recommends First Gene Therapy Treatment for Rare Form of Childhood Vision Loss

  • Voretigene neparvovec (Luxturna) is the first gene therapy evaluated through the CADTH reimbursement review process
  • CADTH recommends reimbursement with conditions, including a price reduction, and offers advice on implementing the recommendation

On November 16, CADTH recommended that Canada’s federal, provincial, and territorial drug plans (except Quebec) should reimburse, with conditions, voretigene neparvovec (also known as Luxturna and licensed by Novartis Pharmaceuticals Canada Inc.). This treatment is the first-ever gene replacement therapy to treat vision loss due to inherited retinal dystrophy caused by biallelic retinal pigment epithelium 65 kDA protein (RPE65) mutations. This is a rare inherited eye disorder that causes progressive vision loss, often leading to complete blindness.

The reimbursement recommendation was made by the independent Canadian Drug Expert Committee at its September 2020 meeting. In arriving at their recommendation, the committee noted clinical trial evidence that voretigene neparvovec, compared with best supportive care, demonstrated statistically significant improvements in:

  • functional vision under low light conditions, as measured at one year post-treatment, and
  • full-field sensitivity threshold one year post-treatment.

At a price of $515,750 per eye, the cost of treating both eyes is more than $1 million per patient. There is substantial uncertainty about the cost-effectiveness of treatment, due largely to uncertainty about its long-term efficacy.

The committee acknowledged that the improvement in functional vision would be considered a meaningful outcome by patients, and that voretigene neparvovec is the first treatment approved in Canada that targets the underlying cause of vision loss in patients with this progressive condition. Several patient groups collaborated to provide one patient group submission to inform this review. The group included Fighting Blindness Canada, Canadian Council of the Blind, CNIB Foundation, and Vision Loss Rehabilitation Canada.

Conditions for Reimbursement

Based on the available evidence, the expert committee outlined that its positive recommendation is contingent on a series of conditions that should be satisfied:

  • Initiation: Patients should be at least four years old, have confirmed biallelic RPE65 mutations, and, although their vision is impaired, they should have viable retinal cells remaining.
  • Prescribing: Treatment should be reimbursed to treat each eye once. An inherited retinal disease specialist should select and evaluate patients, and a retinal surgeon with appropriate training and experience should administer the treatment.
  • Pricing: The price should be reduced.

Implementation Considerations

As part of CADTH’s fit-for-purpose reimbursement review process, special attention is given to the implementation issues that may arise with the introduction of novel cell or gene therapies.

In their recommendation, the expert committee offered insight on the accessibility of genetic testing required to confirm the presence of the biallelic RPE65 mutation, a potential process for measuring retinal cell viability, and considerations for product listing agreements.

Brent Fraser, Vice-President of Pharmaceutical Reviews at CADTH, stated:

Voretigene neparvovec is a novel gene therapy for a rare form of childhood blindness that had no other treatment options until now. The sponsor took advantage of CADTH’s aligned review process with Health Canada and INESSS in Quebec, allowing us to efficiently deliver a final reimbursement recommendation and minimize delays for patients and families who are anxious to see this treatment available in Canada.

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