Volume 219 - Issue 2
Health economic aspects of inherited retinal diseases: looking for cost‐effective treatments
Authors: Benjamin Kamien, Rachael Heath Jeffery and Fred K Chen
Med J Aust 2023; 219 (2): 61-62. || doi: 10.5694/mja2.52012
Published online: 17 July 2023
Published online: 17 July 2023
Both health care costs and broader societal costs should be considered when evaluating the cost-effectiveness of new therapies
Until recently, the management of people with inherited retinal diseases (IRDs) was largely limited to referral for vision aids and registration as being legally blind. This situation is now rapidly changing in the disciplines of ophthalmology and clinical genetics, largely due to the emergence of gene‐based therapies that halt disease progression. IRDs comprise a group of diverse disorders that includes retinitis pigmentosa, Stargardt disease, choroideraemia, Best disease, congenital stationary night blindness, achromatopsia, Leber congenital amaurosis, and similar conditions. Four decades of research have led to the identification of pathogenic variants in more than 300 IRD‐causing genes. While the individual conditions and gene variants are rare, together they affect up to one in 1000 people in Australia, or as many as 25000 people; IRDs are the leading cause of blindness in working age adults.1,2 The loss of central or peripheral vision, profound nyctalopia, and debilitating photophobia have a significant impact on daily activities and consequently the independence of people with these conditions. For example, IRDs can affect navigation, facial recognition, and driving: all significant for quality of life.3
Since the first IRD gene variant was identified in 1984,4 imaging technology has rapidly advanced. Impressive in vivo cellular resolution phenotyping tools are now available,5 and genetic testing, genetic counselling, reproductive carrier screening, and pre‐implantation genetic testing are more widely accessible.6,7,8 Nonetheless, concerns remain about equitable access to the appropriate referral pathways for genetic diagnosis, and also differences in access related to state‐based IRD practices.
Despite major diagnostic advances, gene therapies have only recently started to show great promise as vision‐sparing or vision‐restoring strategies. It is anticipated that further advances will make IRD treatment options more widely available.9 Unfortunately, these therapies are expensive, and justifying government subsidies requires detailed health economics analyses. The first and only gene therapy approved in Australia by the Therapeutic Goods Administration (TGA)10 has already been provided to eight Australian patients with a rare form of RPE65‐associated retinopathy. Further gene therapies are in the pipeline for more common IRDs, some currently in phase 3 clinical trials scheduled for completion in the next few years.11 Trial findings offer people hope that effective gene therapies will become available in clinical practice within five years.11
In this issue of the MJA, Schofield and colleagues report their analysis of the societal and health care costs of IRDs.12 They estimate a lifetime cost of $5.2 million per person with an IRD, of which 87% were societal costs and 13% health care costs. Only 22 of 74 adults in the study were working full‐time (31%) and 22 part‐time (31%), and visual acuity was better than 6/60 for only 35 people (37%); notably, only 32 had National Disability Insurance Scheme (NDIS) packages (43%). Visual acuity was better than 6/60 for ten of the twenty children in the study (50%), and twelve had NDIS packages (60%). The authors did not investigate the effect of peripheral visual field loss, which can also have significant implications for navigation and driving even when visual acuity is normal. Based on a national IRD prevalence of one to two per 2000 population, Schofield and her colleagues estimated the total annual cost of IRDs to be $781 million to $1.56 billion.12
As medical professionals, we often place emphasis on calculating health care costs but fail to consider wider societal costs, which are much higher for IRDs than their health care‐related costs. Schofield and colleagues recommend that both expense types be taken into account when evaluating the cost‐effectiveness of new therapies for which government support is being sought.12 Securing funding for future gene therapies will be challenging. Accordingly, health economic analyses are vital when applying for TGA listing of therapies that could improve the lives of Australians with IRDs. Gene therapies are likely to come at a significant cost, but they will be cost‐effective in the longer term if we consider the increased workforce participation and taxes paid, as well as reducing the use of the NDIS and related services. The article by Schofield and colleagues provides model‐based evidence that can inform such discussions.
Competing interests
Fred Chen receives consultancy fees from Novartis, PYC Therapeutics, and Janssen.
References
- Heath Jeffery RC, Mukhtar SA, McAllister IL, et al. Inherited retinal diseases are the most common cause of blindness in the working‐age population in Australia. Ophthalmic Genet 2021; 42: 431‐439.
- Hanany M, Rivolta C, Sharon D. Worldwide carrier frequency and genetic prevalence of autosomal recessive inherited retinal diseases. Proc Natl Acad Sci U S A 2020; 117: 2710‐2716.
- Heath Jeffery RC, Lo J, Thompson JA, et al. Driving with retinitis pigmentosa. Ophthalmic Genet 2023; https://doi.org/10.1080/13816810.2023.2196338 [online ahead of print].
- Bhattacharya SS, Wright AF, Clayton JF, et al. Close genetic linkage between X‐linked retinitis pigmentosa and a restriction fragment length polymorphism identified by recombinant DNA probe L1.28. Nature 1984; 309: 253‐255.
- Roshandel D, Thompson JA, Heath Jeffery RC, et al. Multimodal retinal imaging and microperimetry reveal a novel phenotype and potential trial end points in CRB1‐associated retinopathies. Transl Vis Sci Technol 2021; 10: 38.
- Britten‐Jones AC, Gocuk SA, Goh KL, et al. The diagnostic yield of next generation sequencing in inherited retinal diseases: a systematic review and meta‐analysis. Am J Ophthalmol 2023; 249: 57‐73.
- Britten‐Jones AC, O'Hare F, Edwards TL, Ayton LN; VENTURE Study Consortium. Victorian evolution of inherited retinal diseases natural history registry (VENTURE study): rationale, methodology and initial participant characteristics. Clin Exp Ophthalmol 2022; 50: 768‐780.
- Schofield D, Lee E, Parmar J, et al. Economic evaluation of population‐based, expanded reproductive carrier screening for genetic diseases in Australia. Genet Med 2023; 25: 100813.
- Hu ML, Edwards TL, O'Hare F, et al. Gene therapy for inherited retinal diseases: progress and possibilities. Clin Exp Optom 2021; 104: 444‐454.
- Therapeutic Goods Administration. Luxturna [Australian prescription medicine decision summaries]. 13 Aug 2020. https://www.tga.gov.au/resources/auspmd/luxturna (viewed June 2022).
- Hu ML, Edwards TL, O'Hare F, et al. Gene therapy for inherited retinal diseases: progress and possibilities. Clin Exp Optom 2021; 104: 444‐454.
- Schofield D, Kraindler J, Tan O, et al. The health care and societal costs of inherited retinal diseases in Australia: a microsimulation modelling study. Med J Aust 2023; 219: 70‐76.
Provenance: Commissioned; not externally peer reviewed.