Gene therapy companies gain clarity on manufacturing, trials and orphan drug status

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Trine K. Tsouderos HRI Regulatory Center Leader, PwC US February 07, 2020


The FDA has released a suite of seven guidance documents on gene therapy to help product developers understand the special considerations the agency will take into account regarding the manufacturing and clinical development of such products.

So far, the agency has approved four gene therapy products, which insert new genetic material into a patient’s cells. However, the FDA expects to greenlight many more in the coming years, given the more than 900 investigational new drug applications it has received for gene therapies.

“Scientific development in this area is fast-paced, complex, and poses many unique questions during a product review; including how these products work, how to administer them safely, and whether they will continue to achieve a therapeutic effect in the body without causing adverse side effects over a long period of time,” said Dr. Peter Marks, director of the FDA Center for Biologics Evaluation and Research, in the announcement of the new, nonbinding guidance.

Addressing questions about product design, the agency released final guidance on the chemistry, manufacturing and control information that manufacturers should submit in investigational new drug applications for gene therapies.

Because these therapies are designed to create permanent or long-lasting changes in the human body, they raise concern that adverse effects may manifest themselves long after a product has been approved. As a result, the FDA issued final guidance on long-term follow-up that offers recommendations about when and how to continue patient monitoring after clinical trials and drug licensing.

The agency offered additional final guidance for gene products targeting rare diseases that includes recommendations not just for manufacturing, but also for establishing preclinical studies and clinical trials. Draft guidance explains how two or more gene therapies for the same rare disorder can qualify for orphan drug designation, with its accompanying financial incentives and market exclusivity.

Other final guidance documents address gene therapies delivered via retroviruses, and those specific to hemophilia and to retinal disorder treatments.

HRI impact analysis

Although just a few gene therapies have FDA approval, the field is surging forward. The agency predicts that by 2025 it will OK 10 to 20 cell and gene therapy products a year.

In his statement, the FDA’s Marks expressed confidence that the framework the agency constructs for product development and review “will set the stage for continued advancement of this cutting-edge field and further enable innovators to safely develop effective therapies for many diseases with unmet medical needs.”

Yet the complexity of regulating this emerging, fast-paced field is not lost on the agency. The FDA said it took stakeholders’ input into account when creating the guidance and will continue to work with product innovators, sponsors, researchers, patients and others.

The agency also indicated that it doesn’t want the regulatory environment to slow progress. It urged gene therapy developers “to make full use” of the expedited programs, such as fast-track designation and priority review, that the FDA offers for products that target unmet medical needs in the treatment of serious or life-threatening conditions.

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Trine K. Tsouderos

HRI Regulatory Center Leader, PwC US

Tel: +1 (312) 241 3824

Crystal Yednak

Senior Manager, Health Research Institute, PwC US

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