RESUMEN
Retinitis Pigmentosa (RP) is a group of inherited retinal dystrophies (IRDs) characterised by progressive vision loss. Patients with RP experience a significant impact on daily activities, social interactions, and employment, reducing their quality of life. Frequent delays in referrals and no standard treatment for most patients also contribute to the high unmet need for RP. This paper aims to describe the evolving therapeutic landscape for RP including the rationale for advanced therapy medicinal products (ATMPs). A review of available data was conducted in three stages: (1) a search of publicly available literature; (2) qualitative research with physicians treating RP patients in France, Germany, Italy, Spain, and the UK; and (3) a review of leading candidates in the RP pipeline. Globally, there are currently over 100 drugs in development for RP; 50% of which are ATMPs. Amongst the 15 cell and gene therapies in late-stage development, 5 leading candidates have been selected to profile based on the development stage, drug target and geography: gene therapies AGN-151597, GS-030 and VMCO-1 and human stem cell therapies jCell and ReN-003. Hereditary retinal diseases are suitable for treatment with cell and gene therapies due to the accessibility of the retina and its immune privilege and compartmentalisation. Therapeutic approaches that aim to rescue photoreceptors (eg gene therapies) require that non-functional target cells are still present, whereas other therapies (eg cell therapies) are not reliant on the presence of viable photoreceptors. Gene therapies may be attractive as their fundamental goal is to restore vision; however, cell therapies will likely have a broader application and do not rely on genetic testing, which can delay treatment. Ensuring effective therapeutic options for RP patients across disease stages requires the continued diversification and advancement of the development pipeline, and sustained efforts to promote early patient identification and timely diagnosis.
RESUMEN
Retinitis Pigmentosa (RP), a group of inherited retinal dystrophies characterised by progressive vision loss, is the leading cause of visual disability and blindness in subjects less than 60 years old. Currently incurable, therapy is aimed at restricting degeneration of vision, treating complications, and helping patients to cope with the psychosocial impact of their disease. Hence, RP is associated with a high burden of disease. This paper describes the current therapeutic landscape for RP and the disease burden for patients, caregivers, and society. A review of available data was conducted in three stages: (1) a literature search of publicly available information on all domains of RP; (2) a systematic literature review using Medline, Embase, the Cochrane Library and grey literature (GlobalData) on epidemiology and cost of RP; and (3) qualitative research with senior physicians treating RP patients in the EU4 and the UK to validate research findings from secondary sources. RP severely impacts the daily lives of over a million people worldwide. Progressive vision loss significantly affects the ability to perform basic daily tasks, to maintain employment, and maintain independence. Consequently, most patients will experience reduced quality of life, with a greater emotional and psychological impact than other conditions related to vision loss such as diabetic retinopathy or age-related macular degeneration. RP is also associated with a high level of carer burden, arising from psychological and financial stress. The therapeutic landscape for RP is limited, with few treatment options and minimal guidance for the diagnosis, treatment, and care of patients. A curative intervention, voretigene neparvovec (Luxturna®), only exists for 1-6% of patients. Although disease management can be successful in developing coping strategies, most patients live with this chronic, progressive condition without interventions to change the disease course. Innovative new therapies can transform the therapeutic landscape, provided appropriate clinical guidance is forthcoming.