> A total of 15 participants received CTX310 and had at least 60 days of follow-up. No dose-limiting toxic effects related to CTX310 occurred. Serious adverse events occurred in two participants (13%): one participant had a spinal disk herniation, and the other died suddenly 179 days after treatment with the 0.1-mg-per-kilogram dose.

> Editing of ANGPTL3 was associated with few adverse events and resulted in reductions from baseline in ANGPTL3 levels.

Two out of 15 having adverse advents seems pretty high, especially since one died. The supplemental material rules this as an unrelated death (https://www.nejm.org/doi/suppl/10.1056/NEJMoa2511778/suppl_f...).

Definitely seems promising for a larger-scale trial, but it seems weird to make such a strong conclusion about adverse reactions.