AbbVie announced new results from its exploratory NOVA phase 2 dose-ranging study evaluating the efficacy and safety of AGN-151607, a novel investigational neurotoxin for the prevention of postoperative atrial fibrillation (POAF) in cardiac surgery patients. The primary endpoint of evaluating the occurrence of continuous atrial fibrillation (AF) = 30 seconds was not met for the modified intent-to-treat (mITT) population; however, the data showed relative risk reduction in specific study populations, such as coronary artery bypass graft (CABG) patients and patients aged 65 years and older. The results were presented at the 2022 American Heart Association Scientific Sessions in Chicago, IL, USA, during the Late-Breaking Science session titled "Treating Atrial and Supraventricular Arrhythmias." Among the observed benefits, relative risk reduction was seen in certain subgroups; specifically, pre-specified CABG patients treated with 125 units of AGN-151607 received the greatest benefit with 29% relative risk (RR) reduction compared to placebo (p=0.15).

In a post hoc analysis of CABG patients aged 65 years and older treated with 125 units of AGN-151607, the study found a greater risk reduction at 51% compared to placebo (nominal p<0.01). Regarding rehospitalization within 30 days following discharge, patients treated with 125 units had lower rates of all-cause rehospitalization within 30 days compared to placebo (8.7% vs. 15.7%, respectively).

In addition, at the time of this analysis, more patients on 125 units (62.9%) were atrial fibrillation-free and anticoagulation-free versus placebo (45.1%) (nominal p<0.05). POAF is the most common complication following cardiac surgery,1 leading to increased morbidity, mortality, increased length of hospital stay, healthcare utilization, and cost. The incidence has not changed in decades, affecting between 30-60% of patients undergoing cardiac surgery.

Currently, treatment options are limited, and there are no approved drugs for the prevention of POAF. The proportion of participants experiencing any AE and rates of AEs leading to discontinuation of the study were numerically similar across the three treatment groups. There were two deaths in those treated with 250 units due to aorto-esophageal fistula (n=1) and cardiac arrest (n=1).

Treatment-emergent cardiovascular AEs rates were heart failure (7.6%, 2.9%, and 3.7%), stroke/TIA (4.8%, 2.9%, and 1.8%), myocardial infarction (1.9%, 1.0% and 0.0), renal failure (6.7%, 4.8%, and 4.6%), and respiratory failure (7.6%, 4.8%, and 5.5%) for placebo, 125 units and 250 units, respectively.