The first FDA-approved gene therapy for inherited retinal disease, voretigene neparvovec (Luxturna, Spark Therapeutics), raised eyebrows when it was approved last year because of its hefty price tag. But this treatment for RPE65-mediated disorders could be a game-changer for affected patients. A recent study has determined that it is cost effective over a lifetime, using a threshold of $50,000 to $150,000 per quality-adjusted life-year (QALY).

The initial price of the therapy in its first year drives the overall cost, based on the current buy-and-bill practice in the United States. However, the study notes that the benefits, such as incremental QALY gains and indirect cost offsets associated with the gene therapy, are distributed over the patients’ lifetimes and are driven largely by assumptions around the duration of the treatment effect.

Researchers compared the incremental cost effectiveness ratio of voretigene with that of standard care for RPE65-mediated inherited retinal disease in 70 patients. Voretigene was associated with lower total costs ($2.2 million vs. $2.8 million) and higher QALY (18.1 vs. 8.6). The study examined a range of scenarios and determined that the gene therapy option remains cost effective if at least 8.8% of the long-term treatment effect continues after its third year when including indirect costs—and 43.3% when excluding indirect costs, assuming a cost threshold of $150,000 per QALY.

The study concluded that many ocular gene therapies in clinical trials have the potential to yield substantial QALY gains and indirect cost savings over patients’ lives, but they have an upfront treatment cost. To determine the cost effectiveness of similar therapies administered in one visit, researchers recommend analyzing treatment effect durability, appropriate selection of disease-specific utilities and careful inclusion of indirect costs.