Laboratory studies evaluating the efficacy of a novel orally administered combination product containing sarolaner, moxidectin and pyrantel (Simparica Trio™) for the treatment and control of flea infestations on dogs

Recent Advancements in the Control of Cat Fleas

Simple Summary

The cat flea Ctenocephalides felis felis is the most important pest of domesticated cats and dogs worldwide. This review covers the recent advancements in the control of cat fleas. Over the years, there has been an interest in using ecologically friendly approaches to control fleas. To date, no biological, natural, or cultural means have been discovered that mitigate flea infestations. The recent registration of novel topical and oral therapies promises a new revolution in the control of fleas and ticks and the diseases associated with them.

Abstract

With the advent of imidacloprid and fipronil spot-on treatments and the oral ingestion of lufenuron, the strategies and methods to control cat fleas dramatically changed during the last 25 years. New innovations and new chemistries have highlighted this progress. Control strategies are no longer based on the tripartite approach of treating the pet, the indoor environment, and outdoors. The ability of modern therapies to break the cat flea life cycle and prevent reproduction has allowed for the stand-alone treatments that are applied or given to the pet. In doing so, we have not only controlled the cat flea, but we have prevented or reduced the impact of many of the diseases associated with ectoparasites and endoparasites of cats and dogs. This review provides an update of newer and non-conventional approaches to control cat fleas.

Efficacy of combination products containing sarolaner, moxidectin and pyrantel (Simparica Trio™) or afoxolaner and milbemycin (NexGard Spectra®) against induced infestations of Ixodes holocyclus in dogs

BACKGROUND

The Australian paralysis tick, Ixodes holocyclus, causes tick paralysis in dogs and cats in the eastern coastal regions of Australia. Prevention is the best option to protect dogs against this potentially fatal disease and sarolaner provides rapid and sustained efficacy against I. holocyclus. In this laboratory study, the efficacy of two combination endectocides containing sarolaner + moxidectin + pyrantel (Simparica Trio™) and afoxolaner + milbemycin (NexGard Spectra^®) was evaluated against an artificial infestation of I. holocyclus.

METHODS

Twenty-four (n =24) foxhounds were randomly allocated to three treatment groups and artificially infested with 30 adult female viable ticks on Days - 1, 7, 14, 21, 28 and 35. On Day 0, dogs in each treatment group were treated with either Drontal^® (control group), Simparica Trio™ at the label dose to provide minimum doses of sarolaner (1.2 mg/kg), moxidectin (24 µg/kg) and pyrantel (5 mg/kg) or NexGard Spectra^® to provide minimum doses of afoxolaner (2.5 mg/kg) and milbemycin (0.5 mg/kg). Live tick counts were performed at 48 and 72 hours after treatment and after each re-infestation on Days 7, 14, 21, 28 and 35. Efficacy was determined at each time point relative to counts for control dogs based on geometric means.

RESULTS

Against an existing infestation, efficacy of both Simparica Trio™ and NexGard Spectra^® was 99.6% and 100% at 48 and 72 h time points, respectively (P = 1.000). Against subsequent weekly infestations, treatment with Simparica Trio™ and NexGard Spectra^® resulted in efficacy of ≥ 97.7% and ≥ 95.5% (P ≥ 0.0911), respectively at the 48 h time point and at the 72 h time point, Simparica Trio™ and NexGard Spectra^® resulted in efficacy of ≥ 99.0% and ≥ 98.4% (P ≥ 0.0511), respectively. There were no treatment-related adverse events in the study.

CONCLUSIONS

Single doses of Simparica Trio™ and NexGard Spectra^® were highly efficacious and provided comparable efficacy against the Australian paralysis tick, I. holocyclus for up to 35 days.

Efficacy of orally administered combination of moxidectin, sarolaner and pyrantel (Simparica Trio™) for the prevention of experimental Angiostrongylus vasorum infection in dogs

BACKGROUND

Infection with Angiostrongylus vasorum may cause severe clinical disease, even death in dogs, however, due to the often non-specific clinical signs, diagnosis is not always straightforward. Regular prophylactic treatment may offer a safe means to protect dogs against infection. The efficacy of a novel oral endectocide containing moxidectin, sarolaner and pyrantel was investigated for the prevention of angiostrongylosis in dogs in three placebo-controlled, randomized, masked studies. The initial study (Study 1) determined the efficacious dosage of moxidectin in the combination product by evaluating three different dose levels, and two follow-up studies (Studies 2 and 3) confirmed the efficacy of the selected moxidectin dose.

METHODS

Animals were infected orally with 200 infective third-stage larvae (L3) of A. vasorum and were treated 28 days later with the combination product or with placebo. Timing of dosing relative to infection allowed for efficacy to be evaluated against the immature adult (L5) stage. Dogs in Study 1 received treatments with oral tablets to deliver 3, 12 or 24 µg/kg moxidectin in combination with 2 mg/kg sarolaner and 5.0 mg/kg pyrantel (as pamoate salt) or placebo. In Studies 2 and 3, Simparica Trio™ tablets were administered to provide minimum dosages of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5.0 mg/kg pyrantel (as pamoate salt). Efficacy of the combination product was calculated as the percent reduction in adult worm counts at necropsy relative to placebo.

RESULTS

In Study 1, the 3, 12 and 24 µg/kg moxidectin dosage in the combination product provided 7.2%, 54.5% and 94.7% efficacy against the immature adult stages of A. vasorum, respectively. Studies 2 and 3 confirmed that the efficacy of 24 µg/kg moxidectin combined with 1.2 mg/kg sarolaner and 5 mg/kg pyrantel in Simparica Trio™ was ≥ 92.9%. All three studies established that a single oral administration of 24 µg/kg moxidectin in the combination product provided effective prophylactic treatment for angiostrongylosis, reduced L1 production and fecal excretion and minimized the tissue damage to the lungs.

CONCLUSIONS

A single oral treatment of dogs with Simparica Trio™ providing moxidectin at a minimum dose of 24 µg/kg was efficacious in the prevention of angiostrongylosis.

Efficacy of a novel oral chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against natural flea and tick infestations on dogs presented as veterinary patients in Europe

Background

A novel chewable oral tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) has recently been developed to provide persistent protection against flea and tick infections for a month, treatment of hookworm and roundworm infections and prevention of heartworm and lungworm disease in dogs. Two field studies were conducted to evaluate the safety and efficacy of Simparica Trio™ against natural flea and tick infestations on dogs in Europe.

Methods

Dogs with natural flea or tick infestations were allocated randomly to treatment on Day 0 with either Simparica Trio™ tablets (flea study: n = 297; tick study: n = 189) to provide 1.2–2.4 mg/kg sarolaner, 24–48 µg/kg moxidectin and 5–10 mg/kg pyrantel (as pamoate salt) or with NexGard® Spectra (afoxolaner + milbemycin oxime) according to the label instructions (flea study: n = 164; tick study: n = 91). Efficacy was calculated based on the mean percent reduction in live parasite counts compared to the respective pre-treatment counts on Days 14 and 30 in the flea study and on Days 7, 14, 21 and 30 in the tick study. To count the fleas, the dog’s entire coat was systematically combed using an extra fine-tooth flea comb until all fleas were removed. For the tick counts, the dog’s entire coat was searched manually. Resolution of the clinical signs of flea allergy dermatitis (FAD) was assessed in flea allergic dogs in the flea study. Palatability was assessed in both studies.

Results

Simparica Trio™ was well tolerated in both studies. Efficacy against fleas was ≥ 97.9% in the Simparica Trio™ group and ≥ 96.1% in the NexGard® Spectra group. Efficacy against ticks was ≥ 94.8% in the Simparica Trio™ group and ≥ 94.4% in the NexGard® Spectra group. Clinical signs of flea allergy dermatitis improved following treatment with Simparica Trio™. Simparica Trio™ tablets were voluntarily and fully consumed on ≥ 78% of the 485 occasions they were offered.

Conclusions

A single oral dose of Simparica Trio™ was safe and highly efficacious against naturally occurring flea and tick infestations for 1 month on dogs. Clinical signs of FAD improved following treatment. Simparica Trio™ was voluntarily and readily consumed by most dogs.

Safety and efficacy of a novel oral chewable combination tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against natural flea infestations in client-owned dogs in the USA

BACKGROUND

One randomized, controlled clinical field study was conducted in 18 general veterinary practices throughout the USA to evaluate the safety and efficacy of a novel oral chewable combination tablet, Simparica Trio™, containing sarolaner, moxidectin and pyrantel for the treatment and prevention of fleas on dogs.

METHODS

Client-owned dogs, from households of three or fewer dogs were eligible for enrollment. Four hundred and twenty-two dogs from 251 households were enrolled. Households were randomly assigned in a 2:1 ratio to treatment with either Simparica Trio™ at the minimum label dose of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel (as pamoate salt) or afoxolaner (NexGard®, Boehringer-Ingelheim) at the label dose. One dog per household was selected as the primary dog for efficacy evaluations. Treatments were dispensed and dogs were dosed in their home environment on Day 0 and on approximately Day 30. Flea counts and examination for clinical signs of flea allergy dermatitis (FAD) were performed at the initial visit the day before or on Day 0 prior to treatment and on Days 30 and 60. Additionally, all dogs were examined for general health at each visit and blood and urine were collected for clinical pathology at screening and Day 60.

RESULTS

Simparica Trio™ reduced geometric mean live flea counts by 99.0% by Day 30 and by 99.7% by Day 60. As a result of the rapid reduction in flea infestations, clinical signs associated with FAD substantially improved following treatment. Simparica Trio™ was well-tolerated and a diverse range of concomitant medications were administered to dogs during the course of the study. Simparica Trio™ chewable tablets were well-accepted by dogs, with the majority of flavored chewable tablets (91.9%) voluntarily consumed by free choice without, or when offered in food.

CONCLUSIONS

Simparica Trio™ administered orally once monthly for two consecutive treatments was safe and effective against natural flea infestations and substantially improved clinical signs associated with FAD in client-owned dogs in a field study conducted in the USA.

Evaluation of the speed of kill of a novel orally administered combination product containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against induced infestations of Ixodes scapularis on dogs

Background

The black-legged (or deer) tick, Ixodes scapularis, commonly infests dogs in the USA and is the vector of important zoonotic pathogens, including Borrelia burgdorferi, the causative agent of Lyme disease. Rapid onset of activity is important in reducing the feeding activity of ticks, thereby reducing the possibility of transmission of infections. The speed of kill of a novel oral combination product, Simparica Trio™ containing sarolaner, moxidectin and pyrantel was evaluated in a well-controlled laboratory study against an existing infestation and subsequent weekly induced infestations of I. scapularis ticks on dogs.

Methods

Dogs were allocated randomly based on host suitability tick counts to treatment with a single dose of either placebo or Simparica Trio™ at the minimum label dose of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel (as pamoate salt). All dogs were infested with approximately 50 unfed adult I. scapularis ticks at a 1:1 sex ratio on Days −2, 7, 14, 21, 28 and 35. Tick counts were conducted at 8, 12 and 24 h after treatment on Day 0 and after each subsequent infestation.

Results

No treatment-related adverse events occurred during the study. Dogs in the placebo-treated group maintained adequate tick infestations for the duration of the study. Day 0 tick counts at 8 h after treatment with Simparica Trio™ were reduced relative to placebo against an existing infestation with efficacy of 67.5%, demonstrating that Simparica Trio™ started killing ticks soon after treatment. Efficacy was 98.4 % at 12 h and 99.4% at 24 h. Rapid speed of kill was maintained throughout the month, with efficacy of ≥ 94.2% at 24 h after re-infestation through Day 28.

Conclusions

A single dose of Simparica Trio™ administered orally to dogs at the minimum label dose of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel (as pamoate salt) was safe and began to kill existing I. scapularis ticks within 8 h after treatment and resulted in ≥ 94.2% efficacy within 24 h against re-infestations for a month.

Efficacy of a novel chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against four common tick species infesting dogs in Europe

BACKGROUND

Tick infestations can cause direct deleterious effects to dogs as a result of tick blood-feeding, and indirectly ticks can transmit disease agents that can be detrimental to the health of both dogs and humans. Six laboratory studies were conducted to support dosage selection and efficacy confirmation of a novel combination of sarolaner, moxidectin and pyrantel against four tick species that commonly infest dogs in Europe.

METHODS

Two studies were conducted against Dermacentor reticulatus (one of which was a dose determination study), two against Ixodes ricinus, and one each against Ixodes hexagonus and Rhipicephalus sanguineus (sensu lato). In each study, eight purpose-bred Beagle or mix-breed dogs were randomly allocated to each treatment group and infested with 50 unfed adult ticks on Days-2, 5, 12, 19, 26 and 33. On Day 0 dogs were treated orally with placebo or the combination product. In the dose determination study, dogs received sarolaner at point dosages of 0.6 mg/kg, 1.2 mg/kg or 2.4 mg/kg in combination with moxidectin and pyrantel, and in all other studies dogs received Simparica Trio™ to provide minimum dosages of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel (as pamoate salt). Efficacy was assessed based on live tick counts conducted 48 hours after treatment and each weekly infestation.

RESULTS

There were no treatment-related adverse events in any study. In the dose determination study, 1.2 mg/kg sarolaner was the lowest dosage evaluated that provided > 90% efficacy for at least 28 days and therefore was selected as the dosage to provide tick control for at least one month following a single oral treatment. In the dose confirmation studies, a single oral dose of Simparica Trio™ provided ≥ 99.2% efficacy against existing infestations of all tick species, and against re-infestations efficacy was ≥ 97.2% against D. reticulatus for 28 days and against all other species for 35 days.

CONCLUSIONS

These studies support the sarolaner dose selected and confirm the efficacy of a single oral dose of Simparica Trio™ against existing infestations and re-infestations of the common tick species infesting dogs in Europe for at least one month.

Efficacy of a novel orally administered combination product containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against induced infestations of five common tick species infesting dogs in the USA

Background

The efficacy of a novel oral combination product, Simparica Trio™, containing sarolaner, moxidectin and pyrantel was evaluated against five tick species that commonly infest dogs in the USA, Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, Ixodes scapularis and Rhipicephalus sanguineus.

Methods

Laboratory studies were conducted against two different strains of each tick species. In each study, 10 purpose-bred Beagle or mixed-breed dogs were randomly allocated to one of two treatment groups based on pre-treatment host-suitability tick counts. Dogs were infested with approximately 50 (45–55) unfed adult ticks on Days -2, 5, 12, 19, 26 and 33. On Day 0, dogs received either a single oral dose of Simparica Trio™ at the minimum label dose of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel (as pamoate salt) or placebo. Tick counts were conducted at 48 h post-treatment and after each subsequent weekly re-infestation for A. maculatum, D. variabilis, I. scapularis and R. sanguineus studies and at 48 hours or at 72 h post-treatment and after weekly re-infestation in the first and second A. americanum studies, respectively.

Results

No treatment-related adverse reactions occurred in any study. In all studies, placebo-treated dogs maintained infestations throughout the entire study duration, and dogs treated with Simparica Trio™ had significantly lower (P ≤ 0.0010) mean live tick counts than placebo-treated dogs at all time-points. Against A. maculatum, D. variabilis, I. scapularis and R. sanguineus, a single oral dose of Simparica Trio™ evaluated at 48 h post-treatment provided ≥ 98.9% efficacy against existing infestations, and within 48 h of re-infestation efficacy was ≥ 90.4% through at least Day 28 (except for R. sanguineus on Day 14 in a single study with an efficacy of 89.7%). Against A. americanum, Simparica Trio™ provided ≥ 99.4% efficacy at ≤ 72 h after treatment of existing infestations and maintained ≥ 98.4% efficacy at ≤ 72 h after re-infestation through at least Day 35.

Conclusions

A single dose of Simparica Trio™ administered orally at the minimum label dosage of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel provided treatment and control of the common tick species infesting dogs in the USA for at least one month.

Efficacy of a new oral chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against induced ascarid infections in dogs

BACKGROUND

Ascarid infections are among the most prevalent intestinal parasitic infections occurring in dogs around the world, with Toxocara canis and Toxascaris leonina commonly observed. Toxocara canis can cause considerable disease in dogs and humans, and year-round prophylactic treatment and control in dogs is recommended. Elimination of immature stages of these parasites before egg-laying will reduce environmental contamination and the risk of infection for both dogs and humans. Studies were conducted to evaluate the efficacy of a novel, oral chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against induced immature adult (L₅) and adult T. canis, and adult T. leonina infections in dogs.

METHODS

Six negative-controlled, masked, randomized laboratory studies were conducted. Two studies each evaluated efficacy against immature adult (L₅) T. canis, adult T. canis, and adult T. leonina. Sixteen to 40 dogs were included in each study. Dogs experimentally infected with the target parasite were dosed once on Day 0 with either placebo tablets or Simparica Trio™ tablets to provide minimum dosages of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5.0 mg/kg pyrantel (as pamoate salt). Efficacy was based on the number of worms recovered at necropsy 7-10 days after treatment compared to placebo control.

RESULTS

Based on geometric mean worm counts, efficacy of the sarolaner + moxidectin + pyrantel combination was ≥ 95.2% against immature adult T. canis, ≥ 97.3% against adult T. canis, and ≥ 89.7% against adult T. leonina. There were no treatment-related adverse events in any study.

CONCLUSIONS

These studies confirm the efficacy of a single dose of a new oral chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against immature adult and adult T. canis, and adult T. leonina infections in dogs.

Efficacy of Simparica Trio™, a novel chewable tablet containing sarolaner, moxidectin and pyrantel, against induced hookworm infections in dogs

Background

Ancylostomatids (‘hookworms’) are among the most important zoonotic nematode parasites infecting dogs worldwide. Ancylostoma caninum and Uncinaria stenocephala are two of the most common hookworm species that infect dogs. Both immature and adult stages of hookworms are voracious blood feeders and can cause death in young dogs before infection can be detected by routine fecal examination. Hence, treatment of both immature and adult stages of hookworms will decrease the risk of important clinical disease in the dog as well as the environmental contamination caused by egg-laying adults, which should reduce the risk of infection for both dogs and humans. The studies presented here were conducted to evaluate the efficacy of a novel, oral chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™), against induced larval (L₄), immature adult (L₅) and adult A. caninum, and adult U. stenocephala infections in dogs.

Methods

Eight negative-controlled, masked, randomized laboratory studies were conducted. Two separate studies were conducted against each of the target parasites and stages. Sixteen or 18 purpose bred dogs, 8 or 9 in each of the two treatment groups, were included in each study. Dogs experimentally infected with the target parasite were dosed once on Day 0 with either placebo tablets or Simparica Trio™ tablets to provide minimum dosages of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5.0 mg/kg pyrantel (as pamoate salt). Timing of dosing relative to parasite inoculation allowed for efficacy to be evaluated primarily against the target parasite stage. Worm counts were conducted 7 or 8 days after treatments during necropsy. Efficacy was based on the number of worms recovered at necropsy compared to placebo control.

Results

Based on geometric mean worm counts, efficacy of Simparica Trio™ was ≥ 98.4% against L₄ larval stage of A. caninum, ≥ 99.8% against immature adult (L₅) A. caninum, and 100% against adult A. caninum and adult U. stenocephala.

Conclusions

These studies confirm the efficacy of a single oral dose of a novel, chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against L₄ larval and immature adult (L₅) A. caninum, and adult A. caninum and U. stenocephala infections in dogs.