The FDA's draft guidance "Safety Assessment of Genome Editing in Human Gene Therapy Products Using Next-Generation Sequencing," published in the Federal Register April 15 under docket FDA-2026-D-1255, enters formal public comment on Monday, April 20. [1] Comments close July 14. The paper's Sunday brief on the 90-day window named the silence of Editas, CRISPR Therapeutics, Intellia, and Vertex through the weekend as the industry's first data point. Monday is when the docket starts counting public submissions.

What the weekend also clarified is the second docket. FDA-2026-D-1256 — the "Plausible Mechanism" framework that the agency published alongside the NGS guidance — has a six-day comment close on April 26. [2] That is the tighter deadline. Plausible Mechanism is the clinical-inference guidance for off-target effects that cannot be detected by sequencing alone. It covers the methodological question the NGS docket does not answer: when can a sponsor credibly claim an off-target edit would not have a clinical effect? The short comment window is the agency's signal that this guidance is near-final.

FDA Commissioner Marty Makary framed both dockets as continuations of the February individualized-therapy framework. CBER Director Vinay Prasad's NGS line — "state-of-the-art sequencing" detects off-target editing and assesses chromosomal integrity — is now matched by the Plausible Mechanism's requirement that sponsors present an integrated biological argument. [3] Sponsors are pushed toward INTERACT and pre-IND engagement early. Day One of the public window begins Monday; six days later, the faster docket closes. Industry silence through the weekend ends on a working day.

-- KENJI NAKAMURA, Tokyo