— Independent appraisal committee voted that current evidence is adequate to demonstrate a net health benefit of sonpiretigene isteparvovec compared to usual care —

BOSTON, May 15, 2025 – The Institute for Clinical and Economic Review (ICER) today released a Final Evidence Report assessing the comparative clinical effectiveness and value of sonpiretigene isteparvovec (Nanoscope Therapeautics) for the treatment of advanced retinitis pigmentosa.

ICER’s report on this therapy was the subject of the April 2025 public meeting of the New England CEPAC, one of ICER’s three independent evidence appraisal committees. 

Downloads: Final Evidence Report | Report-at-a-Glance | Policy Recommendations 

“Many individuals with retinitis pigmentosa develop severe vision loss as the disease progresses and photoreceptor cells are lost,” said ICER’s Chief Medical Officer David Rind, MD. “Researchers have examined the idea of inserting proteins into other cells that remain in the back of the eye to allow those cells to react to light. Sonpiretigene isteparvovec is a one-time gene therapy that codes for such proteins in remaining retinal bipolar cells. We have a number of uncertainties about the efficacy and durability of this therapy given the limited evidence to date, but the underlying scientific approach is remarkable.”

ICER’s Virtual Public Meeting: Voting Results on Clinical Effectiveness and Contextual Considerations 

ICER assessed, and the independent appraisal committee voted on the evidence for the net health benefit of sonpiretigene in adults with advanced retinitis pigmentosa with severe vision loss:

  • A majority of the panelists (10-2) found that current evidence is adequate to demonstrate a net health benefit of sonpiretigene in comparison to usual care.

Panel members also weighed potential benefits and disadvantages beyond the direct health effects and weighed special ethical priorities. Voting highlighted the following as particularly important for payers and other policymakers to note: 

  • There is substantial unmet need despite currently available treatments.
  • The treatment is likely to produce substantial improvement in caregivers’ quality of life and/or ability to pursue their own education, work, and family life.
  • The treatment offers a substantial opportunity to improve access to effective treatment by means of its mechanism of action or method of delivery.

ICER’s Virtual Public Meeting: Voting Results on Long-Term Value for Money 

Sonpiretigene istaparvovec has not yet been approved by the FDA, and the manufacturer has not announced a US price if approved.

Consistent with ICER’s process, because there is no firm estimate yet of a potential launch price for the treatment, the panel did not take a vote on the treatment’s long-term value for money. 

ICER has calculated a health-benefit price benchmark (HBPB) to be between $67,400 to $101,300 for treatment in one eye.

Key Policy Recommendations 

ICER’s independent assessment of value informs the critical decisions that stakeholders across the US health system need to make around pricing and coverage. Following the voting session, a policy roundtable of experts — including clinical experts, patients and patient advocates, the manufacturer, and representatives from US payers — convened to discuss the pricing implications and recommendations to ensure fair access. Key recommendations stemming from the roundtable discussion include: 

  • Researchers and regulators should partner with patients, clinical specialty societies, and manufacturers to validate and standardize patient-centered outcome measures for use in registries and future trials that capture the full range of perceived visual function in individuals with advanced RP with severe vision loss.
  • Given that response to sonpiretigene appears to be widely variable across patients and that the durability of response is uncertain, payers that consider implementing outcomes-based contracts using best-corrected visual acuity (BCVA) should have a mechanism for judging meaningful responses that cannot be captured from BCVA. An outcomes-based contract that allows for patient and clinician reported outcomes and allows for refunds or rebates for treatment effects that are not maintained may be appropriate for a gene therapy that is expected to have a high price.
  • The manufacturer should moderate launch price decisions to reflect the substantial uncertainty regarding treatment response, durability of treatment effect, and longer-term safety.
  • While some payers may consider a requirement that sonpiretigene be administered by retinal specialists or at a center of excellence for retinal care, clinical experts agreed that most ophthalmologists could administer this treatment in their office given the intravitreal route of injection. Payers may consider requiring consultation with a retinal specialist to attest the diagnosis and eligibility for treatment.

ICER’s detailed set of policy recommendations is available in the Final Evidence Report and in the standalone Policy Recommendations document. 

About ICER 

The Institute for Clinical and Economic Review (ICER) is an independent, non-profit research institute that conducts evidence-based reviews of health care interventions, including prescription drugs, other treatments, and diagnostic tests. In collaboration with patients, clinical experts, and other key stakeholders, ICER analyzes the available evidence on the benefits and risks of these interventions to measure their value and suggest fair prices. ICER also regularly reports on the barriers to care for patients and recommends solutions to ensure fair access to prescription drugs. For more information about ICER, please visit www.icer.org.