David Lebwohl
Analyst · Truist
Thanks, John. And welcome, everyone. Beginning with NTLA-2001 for the treatment of transthyretin amyloidosis, or ATTR amyloidosis, we were thrilled to report continued positive interim data from the polyneuropathy arm of our ongoing Phase 1 study at EASL's International Liver Congress in June. These data provided early confirmation that deep reductions in a disease causing protein achieved by a one-time genome editing treatment are in fact durable over time. At all four dose levels tested in the dose escalation portion, editing the TTR gene with 2001 resulted in sustained reductions in protein levels over the follow up period ranging from six months to a year. At the 0.7 and 1.0 mg per kg doses, 2001 led to a greater than 85% mean TTR reduction at day 28, with maximum reductions of 97% and 98%, respectively. These results remain durable through the six months of ongoing follow up. We continue to believe the deep, durable and remarkably consistent levels of protein reduction support NTLA-2001's potential as a one-time treatment that could halt and possibly reverse the disease. In addition, we continue to make great progress in the cardiomyopathy arm of the study. Recall the primary objectives in both arms are to establish safety and an optimal dose to move forward in potential pivotal studies. There are now over 30 individuals who have been dosed with NTLA-2001 across both the polyneuropathy and cardiomyopathy arms, with the first ever systemically administered in vivo CRISPR candidate. For the cardiomyopathy arm, we announced today the completion of the dose escalation portion. While we look forward to presenting the first interim readout from the cardiomyopathy arm later this year, we're pleased to share that the initial findings have been consistent with the data previously ported from a polyneuropathy arm at EASL. Based on the recent data, the 0.7 and 1.0 mg per kg had very similar TTR reductions, have been generally well tolerated. We're now finalizing a fixed dose selection at or near a fixed dose equivalent of 0.7 mg per kg for evaluation in the dose expansion portion. We also announced today that we plan to evaluate the same fixed dose in a second cohort in the dose extension portion of the polyneuropathy arm. The decision to study a second dose was based on three main factors. First, the emerging data from the dose escalation portion of the cardiomyopathy arm. While still in a small number of patients dosed, initial TTR reduction data is indistinguishable after two doses tested. Second, the comparability of performance at 0.7 mg per kg and 1.0 per mg per kg doses in the dose escalation portion of the polyneuropathy arm. And third, while NTLA-2001 has been generally well tolerated, there was a recent adverse events in a patient dosed in the 80 milligram dose expansion cohort in the polyneuropathy arm that informed our decision. A significant elevation in liver enzymes in this patient at day 28 was observed in a routine laboratory assessment. The liver enzymes returned to normal levels without medical intervention. The patient was asymptomatic and had no increase in bilirubin. The event was considered non-serious by the investigator and deemed possibly related to study drug. As a result, we plan to evaluate a common fixed dose in both arms to better inform our future pivotal study design, in line with the goal of the Phase 1 study to identify a dose that delivers the maximum amount of benefit to patients at the lowest dose possible. Overall, this strategy reflects our strong conviction that NTLA-2001 can achieve the deep levels of TTR reduction expected to potentially halt and reverse the disease. We plan to submit a protocol amendment in the coming days. In addition, we expect to present the initial safety data from the 80 milligram dose extension cohort from the polyneuropathy arms at the upcoming NTLA-2001 data released later this year. We are incredibly proud of all the rapid progress in our ongoing Phase 1 study of NTLA-2001. And subject to regulatory feedback from the protocol amendments, we continue to expect to complete enrollment by the end of 2022. And turning now to NTLA-2002, our investigational therapy for the treatment of hereditary angioedema, or HAE. As a reminder, we are targeting the KLKB1 gene in the liver to permanently reduce plasma kallikrein and its activity. Other modalities have shown that a 60% reduction in kallikrein activity leads to a therapeutically relevant reduction in HAE attack. With NTLA-2002, we've shown compelling data in non-human primates where we have achieved and sustained greater than 90% reduction of both kallikrein protein and its activity after a single dose. If these results translate to humans, NTLA-2002 could be a transformative new treatment option for people living with HAE. We continue to make steady progress in the dose escalation portion of our Phase 1/2 study and look forward to sharing initial results from both the 25 and 75 milligram dose cohorts later this year. This interim data readout is expected to include safety, kallikrein reduction and HAE attack rate data. These results will offer an initial view of the safety and activity profile of NTLA-2002 and potentially demonstrate proof of concept for the modularity of our proprietary CRISPR-based LNT platform. I'll now turn over the call to Laura to provide updates on our ex vivo pipeline and R&D progress.