After Roctavian: Invest More, Platformize, and Scale—The Path to Sustainable AAV Gene Therapy
BioMarin’s decision to divest Roctavian, the first gene therapy approved for adults with severe hemophilia A, highlights a recurring challenge for advanced therapeutics: sustaining clinical innovation within existing commercial and reimbursement models. The therapy demonstrated that endogenous factor VIII production and multi-year bleed control are achievable after a single infusion. Yet its discontinuation underscores how fragile the link remains between scientific progress and sustained patient access. The underlying biology of AAV gene transfer continues to mature and so is the understanding of the conditions to which it is applied. But the structures that determine how innovation reaches patients are still constrained by commercial incentives and risk horizons that diverge from those that drive scientific discovery.
Clinical data from Roctavian confirmed that adeno-associated virus–mediated factor VIII delivery can achieve durable hemostatic benefit and substantially reduce dependence on protein replacement therapy. Over extended follow-up, however, expression levels declined and some individuals resumed prophylaxis. These observations highlight the current challenges of AAV gene transfer rather than its failure. In addition, factor VIII gene replacement and expression appears more complex than what originally anticipated. Achieving long-term transgene expression in the context of pre-existing immunity and vector-related immune responses remains a biological and translational challenge.
The constraints facing gene therapy in hemophilia A are not new, but their combined impact has become clearer now that a product has entered the market and begun its slow transition into practice. Biological eligibility remains narrow: pre-existing antibodies against AAV5 and a history of factor VIII inhibitors exclude many potential candidates, while immune memory prevents re-dosing. These biological limits intersect with the economic structure of care in ways that are particularly acute in hemophilia A. Health systems are not yet fully equipped to account for therapies consisting of a single administration whose cost is immediate but whose clinical return extends over many years. In this setting, AAV gene therapy exposes the tension between a one-time intervention and health systems structured for chronic, recurrent treatment.
In hemophilia A, comparison with emicizumab and other subcutaneous prophylactic agents is unavoidable. These therapies provide consistent bleed prevention, easy administration, and extensive real-world evidence, setting a high clinical and economic benchmark for any successor. A one-time gene therapy must therefore demonstrate not only efficacy but sufficient durability and predictability to justify new models of care and reimbursement. For developers, progress now depends on focused innovation: refining vectors, modulating immune responses, and improving manufacturing to extend expression, broaden eligibility, and lower cost. Yet technical advance alone will not ensure viability. Long-term success will require parallel change in how value is assessed and sustained: multi-year payment models, outcome-based contracts, and registries capable of capturing true durability of benefit.
Patients should remain at the center of these decisions. The significance of Biomarin’s choice to divest Roctavian lies not only in its commercial implications but in the disruption it creates for those awaiting treatment. That is the real loss, and it should motivate the field to build more resilient paths from laboratory to the patient. Ensuring continuity from research to clinical availability should be viewed as part of the ethical responsibility that accompanies development of transformative therapies.
Similar withdrawals and divestments across the field reflect the difficulty of sustaining innovation when long-term value collides with short-term economics rather than failure of science. The response must be to innovate further: technically, to make gene therapies more durable and broadly applicable, and structurally, to build payment and access models that can support them. The real test of progress will be whether we can align these scientific and systemic advances so that transformative treatments reach the patients they were designed to serve and remain accessible once they do.