The FDA has outlined new draft guidance on what should be submitted in a clinical trial application and potentially concerning safety issues to track the genome editing products.

The guidance recommends at least 15 years of long-term follow-up after product administration, aligning with past gene editing advice.

The draft guidance points to several specific risks associated with genome editing, including off-target editing, unintended consequences of on-and off-target editing, and the unknown long-term effects of on- and off-target editing.

The FDA is upfront about the risks of genome editing, as Bluebird bio Inc (NASDAQ:BLUE) and others have been hit with clinical holds. 

Related: FDA Pushes Review Period For Bluebird bio's Neurodegenerative Disease, Thalassemia Gene Therapies.

The agency also calls for adequate monitoring of any off-target editing and proper assessment of the outcomes of unintended consequences of on- and off-target editing.

"When developing a human GE [genome editing] product, we recommend that sponsors consider: 1) the method by which the DNA sequence change will be achieved; 2) the type of genomic modification needed for the desired therapeutic effect, and 3) the delivery method of the human GE components," the draft says.

On the clinical end, the agency notes that the first-in-human trials "generally should be designed to enroll only subjects for whom no other treatment options are available or acceptable."

FDA also says that "in some instances, subjects with the less advanced or more moderate disease may be appropriate for inclusion in first-in-human clinical studies."