Safety of an oral combination of moxidectin, afoxolaner, and pyrantel pamoate in dogs

NexGard®PLUS (moxidectin, afoxolaner, and pyrantel pamoate), is an oral combination product for dogs indicated for the prevention of heartworm disease, the treatment and prevention of flea and tick infestations, and the treatment of gastro-intestinal nematode infections. The safety of this product in dogs was evaluated in three studies. Study #1 was a margin-of-safety study conducted in puppies, dosed six times at 28-day intervals at 1X, 3X, or 5X multiples of the maximum exposure dose (equivalent to 24 μg/kg moxidectin, 5 mg/kg afoxolaner, and 10 mg/kg pyrantel). In Study #2, the product was administered to ABCB1-deficient collie dogs at a 1X dose twice at a 28-day interval, and at a 3X or 5X dose once. Study #3 evaluated the safety of the product at 1X and 3X doses administered three times at 4-week intervals, to dogs harboring adult Dirofilaria immitis. In the three studies, the safety was evaluated on the basis of multiple clinical observations and physical examinations, including a complete assessment of toxicity to macrocyclic lactones, and on comprehensive clinical and anatomical pathology evaluations in Study #1. No clinically significant combination product-related effects were observed in any of the three studies. No signs of macrocyclic lactone toxicity were observed in the ABCB1-deficient collie dogs. Some mild and self-resolving instances of emesis or diarrhea were occasionally observed in the 3X and 5X dosed dogs. NexGard® PLUS was demonstrated to be safe following multiple administrations in puppies, in ABCB1-deficient collie dogs, and in microfilaremic dogs infected with adult D. immitis.

The Heart Failure Optimization Study (HF-OPT): rationale and design

BACKGROUND

According to the current guidelines, implantable cardioverter-defibrillators (ICD) for primary prevention in patients with heart failure and reduced ejection fraction (HFrEF) should not be considered until optimal guideline-directed medical therapy (GDMT) has been achieved for a minimum of 3 months. Optimization of GDMT often needs time beyond 3 months after diagnosis. The aim of the Heart Failure Optimization Study (HF-OPT) is to evaluate the recovery of left ventricular function beyond 3 months after diagnosis of newly diagnosed HFrEF.

METHODS

The HF-OPT multicenter study is comprised of two non-randomized phases (registry and study). During the first 90 days a wearable cardioverter-defibrillator (WCD) is prescribed and patients are enrolled in an observational pre-study registry. Registry subjects meeting inclusion criteria for the study portion at day 90 have ongoing left ventricular ejection fraction (LVEF) reassessment at 90, 180 and 360 days after the index hospital discharge, regardless of continued WCD use. Approximately 600 subjects will be enrolled in the study portion. Of those, one-third are anticipated to start the study phase at day 90 with reduced LVEF. The primary objective of this study is to observe the rate of recovery of LVEF > 35% between 90 and 180 days, while key secondary endpoints include mortality and WCD recorded arrhythmias and shocks.

DISCUSSION

The HF-OPT study will provide important information on the rate of additional recovery of LVEF > 35%, between 90 and 180 days, in newly diagnosed HF with reduced LVEF patients being titrated with GDMT. The results of the study may impact indications for primary prophylactic ICD implantation.

Comparison of modulation of Kv1.3 channel by two receptor tyrosine kinases in olfactory bulb neurons of rodents

Activation of the receptor tyrosine kinase (RTK), insulin (IRK) or neurotrophin B (TrkB), was characterized and compared in olfactory bulb neuron (OBN) cultures from Sprague Dawley rats and sv129 B6 mice. Current suppression attributed to modulation of the delayed rectifier, Kv1.3, a voltage-gated potassium (Kv) channel of the Shaker family, was observed following acute application of the growth factors, insulin or brain-derived neurotrophic factor (BDNF), to mitral cells of either rodent model. Using site-directed mutagenesis of putative tyrosine phosphorylation recognition motifs in the channel, we find that stimulation of Kv1.3 with these growth factors causes multiple phosphorylation, albeit via different residue combinations that are RTK specific.