By: Peter Marks, M.D., Ph.D., Director, Center for Biologics Evaluation and Research
Gene therapy has been on the horizon for several decades and has now become a reality in the United States. There are now three approved products: two cell-based gene therapies for cancers of the blood (Kymriah and Yescarta) and one directly-administered gene therapy (Luxturna) for an inherited disorder of the retina of the eye. Numerous gene therapy products are in development to address unmet medical needs, such as those for the treatment of diseases ranging from hemophilia to spinal muscular atrophy. The progress and demand in this field is also evident in the more than 800 active investigational new drug applications for gene therapies on file with FDA.
To keep pace with the remarkable and continuing growth of gene therapy, FDA’s Center for Biologics Evaluation and Research (CBER) has also been growing to take on the challenges of product development and to work with developers to help address those challenges. The National Institutes of Health (NIH) has been and continues to be a leader in the field of gene therapy. Over the years, FDA has developed a comparable cadre of experts, who both review gene therapy applications and conduct applied research relevant to the field. FDA has made it a priority to field a strong bench of highly-skilled and knowledgeable experts in the cutting-edge science behind gene therapy, including genome editing technologies, novel gene delivery methods, and advanced manufacturing technologies.
Because of this now strong scientific expertise at CBER, the FDA is working to streamline the review and safety reporting requirements for gene therapy protocols. Additionally, NIH Director Dr. Francis Collins announced last week that the NIH’s Recombinant DNA Advisory Committee (RAC), for which the original mandate was to follow, and provide advice on safety and ethical issues associated with emerging biotechnologies, will transition to become the Novel and Exceptional Technology and Research Advisory Committee (NExTRAC), and will focus on the evaluation of new biotechnologies and emerging applications that represent both great scientific opportunities and significant ethical and safety challenges.
FDA’s efforts to support development of gene therapy products go further than simply administrative streamlining. The agency is committed to the application of all the available expedited programs, as appropriate, to facilitate the development of gene therapy products. The more recently enacted Regenerative Medicine Advanced Therapy (RMAT) designation is particularly well-tailored to help in this regard. FDA also issued six draft gene therapy guidance documents in July 2018, which, following public comment, are now in the process of being finalized. And the agency intends to issue additional guidance relevant to gene therapies this year.
To help product developers speed development and avoid unnecessary preclinical testing or unnecessary clinical investigation, CBER has implemented the INTERACT program to provide sponsors of innovative products with informal regulatory advice about preclinical requirements, manufacturing, and clinical development programs very early on, even before the start of any formal regulatory filings. Both academic and industrial sponsors are now taking advantage of this program and the feedback has been uniformly positive. Going forward, the agency will evaluate the program to determine what improvements can be made to assist sponsors.
While every aspect of gene therapy product development is critical, FDA has identified product manufacturing as the most crucial issue to be addressed. Quality manufacturing capacity is limiting the broader application and clinical development of gene therapy; this limited capacity directly impacts the ability to produce high-quality gene therapy products with well-defined critical quality attributes. Such limitations in manufacturing are also very likely driving up overall costs. To address these challenges, CBER is actively engaging in internal and external applied scientific research, including awarding grants to foster advanced manufacturing technologies.
Through FDA’s work, including collaborations with stakeholders, the agency will continue to foster the development of transformational technology that will facilitate the broad application of safe and effective gene therapy products that have the potential to alleviate many conditions previously out of reach of therapeutic intervention. We are committed to working with the scientific community and industry to facilitate the availability of these treatments to patients.