Clinical Data The interim data released today cover the first six ATTRv-PN patients across two single-ascending dose cohorts of the Phase 1 study, which is currently being conducted in the United Kingdom and New Zealand. Single doses of either 0.1 mg/kg or 0.3 mg/kg of NTLA-2001 were administered systemically. Reductions in serum TTR levels were measured from baseline to day 28. Treatment with NTLA-2001 led to dose-dependent reductions in serum TTR, with mean reductions of 52% among the three patients in the 0.1 mg/kg dose group, and 87% among the three patients in the 0.3 mg/kg dose group, including one patient with a 96% reduction. By contrast, the standard of care for ATTRv-PN, which requires chronic treatment, typically yields TTR reductions of approximately 80%.  

At both dose levels, NTLA-2001 was generally well-tolerated by the six patients included in the interim analysis, with no serious adverse events and no liver findings by day 28. Given the safety and tolerability profile so far, NTLA-2001 is continuing to be evaluated in the dose-escalation portion of the study, to determine if a higher dose could result in a deeper reduction in disease-causing protein levels leading to the potential for more meaningful clinical benefit. As of the date of this release, Cohort 3, evaluating NTLA-2001 at the 1 mg/kg dose level, is actively enrolling.