On the eve of DNA Day, leaders in the gene therapy community have co-signed a letter to Alex Azar, the Secretary of the Department of Health and Human Services (HHS), urging a “binding global moratorium” on germline editing.

The letter is signed by more than 60 luminaries in the fields of gene therapy and genome editing and follows worldwide condemnation of the reports that emerged in November 2018 of the birth of twins that had been gene edited as embryos (see Davies K., GEN 2018).

“Performing human germline clinical experimentation of this kind is currently irresponsible, and we condemn it in the strongest possible terms,” the letter states. “We strongly believe the editing of human embryos that results in births carries serious problems for which there are no scientific, ethical, or societal consensuses. As a result, we contend that such human genetic manipulation should be considered unacceptable and support a binding global moratorium until serious scientific, societal, and ethical concerns are fully addressed.”

The full letter, which was orchestrated by the American Society of Gene & Cell Therapy, can be found here.

Among the signatories are several prominent figures in the genome editing field such as Feng Zhang, PhD, David Liu, PhD, and Keith Joung, MD, PhD, co-founders of Editas Medicine, along with interim CEO Cindy Collins and other colleagues; Charles Gersbach, PhD (Duke University); Rachel Haurwitz, PhD, president/CEO Caribou Biosciences; Erik Sontheimer, PhD (RNA Therapeutics Institute, University of Massachusetts Medical School); Fyodor Urnov, PhD (Altius Institute); and John Evans, CEO of Beam Therapeutics.

Also supporting the call are many leaders in the gene therapy arena, including Jean Bennett, MD, PhD (Perelman School of Medicine at University of Pennsylvania); Beverly Davidson, PhD (University of Pennsylvania); Ted Friedmann, MD (University of California, San Diego); Guangping Gao, PhD (UMass Medical School); Mark Kay, MD, PhD (Stanford University); Eric Olson, PhD (UT Southwestern Medical Center); Michel Sadelain, MD, PhD (Memorial Sloan Kettering Cancer Center); and Jim Wilson, MD, PhD (University of Pennsylvania).

Also signing the letter is Terrence R. Flotte, MD, provost and dean of the University of Massachusetts Medical School, and the editor-in-chief of Human Gene Therapy (published by GEN’s publisher, Mary Ann Liebert Inc.)

Somatic potential

While calling for a hold on future germline research until there is a “societal consensus” to proceed, the signatories stress the immense potential of somatic genome editing for the understanding and treatment of human disease, citing promising advances in the treatment of sickle cell disease, beta-thalassemia, blindness, muscular dystrophies, hemophilia, and cancer.

“Although clinical trials will be required to demonstrate the efficacies of these approaches, we believe that current scientific methodology is sufficient to define and correct the inevitable issues related to safety and efficacy needed to move forward in the clinic… We consider it unlikely that somatic cell gene editing will give rise to new or unique ethical concerns substantially different from those associated with other forms of research and therapeutics.”

The moratorium letter echoes a similar call published in Nature last month co-authored by Eric Lander, PhD, Emmanuelle Charpentier, PhD, and 16 colleagues (including the Editas co-founders). Neither that article nor the letter to HHS Secretary Azar, however, is signed by Jennifer Doudna, one of the pioneers of CRISPR editing technology who led the call for international debate of the societal and ethical implications of germline editing in 2015.