The departure of Peter Marks from the Food and Drug Administration marks the end of an era for cell and gene therapy development in the United States. As director of the Center for Biologics Evaluation and Research (CBER) since 2016, Marks played a pivotal role in shepherding numerous groundbreaking treatments to market, including the first approved gene therapy, initial cellular cancer treatments, and pioneering CRISPR-based medicines.
Marks submitted his resignation on Friday, citing disagreements with Health and Human Services Secretary Robert F. Kennedy Jr. His exit creates uncertainty in a field already facing significant challenges, particularly around investment and development costs.
During his tenure, Marks championed flexible regulatory approaches that helped accelerate the development and approval of advanced therapies, especially for rare diseases. Under his leadership, the FDA approved over 40 cell and gene therapy products since 2017, according to the Alliance for Regenerative Medicine.
“He kept things safe and he kept things moving,” noted Stephan Grupp, who leads the cell therapy and transplant section at Children’s Hospital of Philadelphia and helped develop the first CAR-T therapy. Industry experts have praised Marks’ scientific expertise and commitment to establishing regulatory frameworks for these novel treatments.
His advocacy for expedited approval pathways, while controversial at times, was driven by a desire to encourage investment in treatments for rare conditions. This approach was exemplified in the 2024 approval of Sarepta Therapeutics’ Elevidys for Duchenne muscular dystrophy, where Marks twice overruled other FDA officials to support the therapy’s authorization despite mixed clinical trial results.
The cell and gene therapy sector now faces additional uncertainty following Marks’ departure. Stock prices of several gene therapy companies declined Monday as investors processed the news. Analysts suggest that companies developing Duchenne treatments could face stricter requirements, while those working on cell therapies for autoimmune conditions might encounter less regulatory flexibility.
The impact extends beyond individual companies. Major academic centers conducting cell therapy research depend heavily on effective FDA oversight, making the agency’s existing staffing shortages even more concerning in light of recently announced government job cuts.
During his tenure, Marks prioritized building the FDA’s expertise in reviewing complex biological products, with his team making
significant strides in modernizing the regulatory framework for these therapies. The Alliance for Regenerative Medicine highlighted his efforts in recruiting essential scientific personnel and updating regulatory processes to handle an expanding pipeline of advanced therapies.
Some industry observers remain cautiously optimistic about the future. Incoming FDA commissioner Marty Makary has indicated support for flexible approval pathways in cases of rare, life-threatening diseases. Additionally, other FDA leaders, including Nicole Verdun, who directs the Office of Therapeutic Products, have shown support for accelerated approvals.
However, prominent figures in the field express concern about finding a suitable replacement. Katherine High, a respected gene therapy researcher, noted the difficulty of finding a successor with Marks’ capabilities, while Nicole Paulk, CEO of Siren Biotechnology, emphasized his crucial role in advancing treatments for rare pediatric diseases.
In his resignation letter, Marks urged the FDA to maintain momentum in expediting treatment development for genetic diseases, highlighting the transformative potential of these therapies. As the field continues to evolve, his departure leaves a significant void in leadership at a critical juncture for cell and gene therapy
development.