Quarter Century Update: The Continued Unknowns of Cell and Gene Therapy

The past 25 years, from 2000 to 2025, have been an unprecedented and rapid period of development of the field of cell and gene therapy. A number of critical breakthroughs have occurred in this time, and the technologies have gone from preclinical musings to realities of standard clinical practice, at least in a few key indications like hematologic malignancies and neuromuscular disease. To get a perspective on how far we've come, and how far we have yet to go, CGTLive® reached out to Deborah Phippard, PhD, the chief scientific officer of Precision for Medicine, and Renier Brentjens, MD, PhD, the chair of the department of medicine and the deputy director at Roswell Park Comprehensive Cancer Center, to hold a Special Report discussion on the topic entitled: "Quarter Century Update: What’s Holding up Progress in Development? Where Have We Seen the Most?"

In this exchange, Brentjens and Phippard discussed how the pharmacology of cell therapy remains highly complex and not yet fully understood. Brentjens explained that dosing for CAR T-cell therapies is unpredictable because the treatment behaves as a “living drug,” with efficacy and adverse events depending on factors like disease burden and T-cell characteristics. Phippard concurred, adding that gene therapy faces similar challenges, as effective dosing depends on variables like delivery method, viral vector type, and tissue targeting, all of which can affect durability and efficacy. Brentjens concluded by likening the current stage of the field to the early days of penicillin—scientists know that it works, but are still uncovering why and how, underscoring how young and continuously evolving these therapeutic technologies still are.