Efficacy of lotilaner (Credelio™) against the adult cat flea, Ctenocephalides felis and flea eggs following oral administration to dogs

Efficacy of lotilaner against myiasis caused by Cochliomyia hominivorax (Diptera: Calliphoridae) in naturally infested dogs

BACKGROUND

The New World screwworm fly, Cochliomyia hominivorax, is widely distributed across South America. This parasitic insect is a significant cause of primary myiasis in animals, including dogs. There is an urgent need for a rapid and efficient treatment to improve the recovery of affected animals. In the present study we evaluated the potential of lotilaner for the treatment of myiasis caused by C. hominivorax larvae in naturally infested dogs. Lotilaner belongs to the isoxazoline class of chemical compounds and is marketed as Credelio™ for use against ticks and fleas in dogs and cats.

METHODS

Eleven dogs with naturally acquired myiasis were enrolled in this study based on the severity of lesions and the number of identified larvae. All animals received a single oral administration of lotilaner at a minimum dose of 20.5 mg/kg body weight. After treatment, the number of expelled larvae, live or dead, was determined at 2, 6 and 24 h, and the larval expulsion rate, larvicidal effect and overall efficacy were calculated. After 24 h, the remaining larvae were removed, counted and identified. The lesions were cleaned, and palliative treatment was administered when necessary, according to the animal's health status.

RESULTS

All larvae were identified as C. hominivorax. The larval expulsion rate was 80.5% and 93.0% at 2 and 6 h post-treatment, respectively. Lotilaner showed an overall efficacy of 100% at 24 h post-treatment.

CONCLUSIONS

Lotilaner demonstrated a rapid onset of action and a high efficacy against C. hominivorax. We therefore recommend lotilaner for the effective treatment of myiasis in dogs.

Safety and efficacy of lotilaner ophthalmic solution, 0.25% for the treatment of blepharitis due to demodex infestation: A randomized, controlled, double-masked clinical trial

PURPOSE

To evaluate the safety and efficacy of lotilaner ophthalmic solution, 0.25% for the treatment of blepharitis due to Demodex infestation compared to vehicle control.

METHODS

In this phase II, randomized, controlled, double-masked clinical trial, 60 eligible participants with Demodex blepharitis were randomly assigned in a 1:1 ratio to receive either topical lotilaner ophthalmic solution, 0.25% (Tarsus Pharmaceuticals, Inc., Irvine, CA) (study group) or the vehicle without lotilaner (control group) bilaterally twice a day for 28 days. Participants were followed at Days 7, 14, 28, 60 and 90. The efficacy parameters were change in collarette grade and Demodex density at Day 28. Safety parameters were adverse events, changes in corrected distance visual acuity (CDVA), intraocular pressure (IOP) and slit-lamp biomicroscopy.

RESULTS

The study group showed a statistically significant decrease in collarette grade compared to the control group beginning at Day 14 (p = 0.003) in the upper eyelid and at Day 28 (p = 0.003) in the lower eyelid. Decreases in both lids were maintained through Day 90 (p < 0.001). At Day 28, mite eradication was achieved in 66.7% and 25.9% of eyes in the study and control group (p = 0.005); at Day 90, these proportions were 68.2% and 18.5% (p = 0.001), respectively. No serious adverse events or clinically significant changes in CDVA and IOP were observed.

CONCLUSION

For Demodex blepharitis, treatment with lotilaner ophthalmic solution, 0.25% for 4 weeks is safe and effective. The improvement in collarette grade and mite density observed during the treatment period persisted for at least two months following treatment cessation.

Field study to investigate the effectiveness and safety of a novel orally administered combination drug product containing milbemycin oxime and lotilaner (Credelio® Plus) against natural flea and tick infestations on dogs presented as veterinary patients in Europe

BACKGROUND

A pivotal randomised, blinded, positive-controlled, multicentre, European field study was conducted to evaluate the effectiveness and safety of a novel combination tablet of lotilaner and milbemycin oxime (Credelio® Plus) administered orally to client-owned dogs naturally infested with fleas and/or ticks.

METHODS

In this field study, households with flea- or tick-infested dog(s) were enrolled on Day 0 into the study to provide data for either the tick or flea infestation cohorts. Households were randomised in a 2:1 ratio to receive either the combination investigational product (IP, Credelio Plus® tablets) or the control product (CP: Nexgard Spectra® tablets). Dogs were administered IP (flea cohort n = 135; tick cohort: n = 147) or CP (flea cohort: n = 67; tick cohort: n = 74) once every 4 weeks for a total of three times at a dose rate of 20.0-41.5 mg/kg bodyweight lotilaner and 0.75-1.53 mg/kg bodyweight milbemycin oxime (IP) or as recommended (CP). Percentage reduction was calculated by comparing individual dog flea and tick counts at each assessed post-treatment time point to their respective baseline (pre-treatment) infestation. Resolution of the clinical signs of flea allergy dermatitis (FAD) was assessed in flea-allergic dogs on the days that flea counts were performed.

RESULTS

Flea effectiveness of Credelio Plus® after 3 consecutive monthly treatments was 100% against Ctenocephalides felis, C. canis and Pulex irritans. Tick effectiveness of Credelio Plus® over the same time frame was 99.3% for Ixodes ricinus and 100% against Rhipicephalus sanguineus (s.l.). Flea effectiveness of the CP after three consecutive monthly treatments was 100% against C. felis, C. canis and P. irritans. Tick effectiveness of the CP over the same time frame was 99.8% for I. ricinus and 100% against R. sanguineus. Credelio Plus® was well tolerated based on the safety assessments in all treated dogs in this field study. Within both treatment groups there was a reduction in total FAD scores from baseline.

CONCLUSIONS

This pivotal European field study demonstrated the excellent effectiveness and safety of a combination of lotilaner and milbemycin oxime (Credelio Plus®) administered orally to dogs naturally infested with fleas and/or ticks.

Long-term and acute safety of a novel orally administered combination drug product containing milbemycin oxime and lotilaner (Credelio® Plus) in juvenile and adult dogs

BACKGROUND

The combination of milbemycin oxime (MO) and lotilaner (Credelio® Plus) is a novel systemic endectocide that provides month-long effectiveness in dogs after a single oral treatment. The safety of Credelio® Plus flavored chewable tablets was investigated in three target animal safety studies. Two studies (one in juveniles and one in adults) evaluated the long-term safety, and one study evaluated the acute safety of the product when administered orally at the upper end of the recommended dose range (0.75-1.53 mg/kg MO and 20-41 mg/kg lotilaner) and multiples of this dose.

METHODS

The objectives of these studies were to determine the long-term and acute safety of MO and lotilaner flavored chewable tablets in healthy dogs. All three studies were randomized, blinded, parallel-group design studies in healthy Beagle dogs. In each of the two long-term studies, 32 dogs were randomized among four groups to untreated controls or to treated groups at target doses of 1X, 3X, or 5X. Treatment was administered on seven (adult dogs) or nine (juvenile dogs) occasions with dosing every 4 weeks. In the acute study, 48 dogs were randomized among four groups to untreated controls or to treated groups at 1X, 3X, or 6X. In all three studies, the control group was administered placebo tablets. All dogs were fed 30 to 45 min prior to treatment and the assessment of safety was based on health observations, complete physical/neurological examinations, and food consumption. For the long-term safety studies, safety assessments also included clinical pathology evaluations (hematology, clinical chemistry and urinalysis), body weight, pharmacokinetic blood collections, and macroscopic and microscopic examinations of collected tissues.

RESULTS

MO and lotilaner did not induce any treatment-related adverse effects based on health observations, physical/neurological examinations, or food consumption in the long-term or acute studies. Additionally, in the long-term studies, MO and lotilaner did not induce any treatment-related effects on clinical pathology, body weight, and macroscopic and microscopic examinations.

CONCLUSIONS

These three studies demonstrate that Credelio® Plus has a wide safety margin when administered at monthly intervals to puppies and dogs at the high end of the commercial dose band.

Field study to investigate the effectiveness and safety of a novel orally administered combination drug product containing milbemycin oxime and lotilaner (Credelio® Plus) for the prevention of heartworm disease (Dirofilaria immitis) in client-owned dogs in the USA

BACKGROUND

Dirofilaria immitis, a globally distributed filarial parasite of dogs, is known to cause serious or fatal cardiopulmonary disease. Client-owned dogs were enrolled in a clinical field study in the USA to evaluate the clinical effectiveness and field safety of an orally administered combination investigational product (IP) containing milbemycin oxime and lotilaner (Credelio® Plus) as compared to a control product (CP) for the prevention of heartworm disease when administered monthly for 11 consecutive months.

METHODS

In this 11-month field study, 319 dogs ≥ 8 weeks old confirmed to be heartworm-negative were enrolled from eight geographically distinct US veterinary clinics, including sites in the southern USA and Mississippi River Valley. The dogs were treated with either the IP combination product at 0.75-1.53 mg/kg milbemycin oxime and 20-41.5 mg/kg lotilaner (n = 159) or the CP (Sentinel® Flavor Tabs®; milbemycin oxime/lufenuron) at the label-recommended dose rate (n = 158.) On day 330, effectiveness was evaluated in each dog using antigen and microfilarial (modified Knott's) testing to assess the establishment of any patent adult heartworm infections.

RESULTS

All dogs treated with the IP combination product and the CP tested negative (100% prevention) for heartworm infection on day 330. The IP combination product tablets containing milbemycin oxime and lotilaner were well tolerated based on the safety assessments in all treated dogs.

CONCLUSIONS

This multi-site clinical study using client-owned dogs demonstrated that monthly use of flavored, chewable tablets containing a combination of milbemycin oxime and lotilaner administered orally under end use conditions is safe for dogs. None of the enrolled dogs developed heartworm infections. Eleven consecutive monthly treatments of the IP provided 100% prevention of heartworm disease caused by D. immitis.

Effectiveness of a novel orally administered combination drug product containing milbemycin oxime and lotilaner (Credelio® Plus) for the treatment of larval and immature adult stages of Ancylostoma caninum in experimentally infected dogs

BACKGROUND

The hookworm, Ancylostoma caninum, is a common and important zoonotic intestinal nematode parasite that infects dogs globally. Both the immature and adult stages of A. caninum ingest large volumes of blood during the feeding process and can cause severe anemia and death in young dogs, even before patent infections can be diagnosed using routine faecal examination methods. Thus, effective treatment of any pre-patent stages of immature hookworms can reduce or eliminate the risk of clinical disease in infected dogs and additionally reduce environmental contamination of eggs and infective larvae. Two randomized, blinded, GCP-compliant, pivotal laboratory dose confirmation studies were conducted to evaluate the effectiveness and safety of a new novel combination of lotilaner and milbemycin oxime tablets (Credelio Plus^®) administered orally to dogs experimentally infected with immature (L4 and immature adult [L5]) stages of A. caninum.

METHODS

Treatments using the intended global commercial tablet formulation of Credelio Plus were administered in a time frame relative to inoculation with infective larvae so that effectiveness could be assessed against each specific immature stage of A. caninum. In each study, dogs were randomized to one of six (study 1) or four (study 2) treatment groups. Each treatment group contained 8 (study 1) or 10 (study 2) dogs that had been experimentally inoculated with infective A. caninum larvae on day 0 and were dosed once on day 7 or day 11. Enrolled subjects were administered placebo tablets, Credelio Plus tablets, or lotilaner mono tablets to provide minimum dosages of 0.75 mg/kg of milbemycin oxime and 20 mg/kg of lotilaner. All dogs were necropsied 5 days after their respective treatment. All nematodes recovered from the gastrointestinal tract at necropsy were counted by species and stage.

RESULTS

For both dose confirmation studies and based on geometric mean worm counts, efficacy of Credelio Plus was ≥ 97.3% against L4 larval stage of A. caninum and ≥ 98.7% against immature adult (L5) A. caninum.

CONCLUSIONS

These studies demonstrated that the orally administered Credelio Plus combination tablet was highly efficacious in treating immature (L4 and immature adult [L5]) stages of A. caninum in experimentally infected dogs.

Effectiveness of Credelio® Plus, a novel chewable tablet containing milbemycin oxime and lotilaner for the treatment of larval and immature adult stages of Toxocara canis in experimentally infected dogs

BACKGROUND

The ascarid, Toxocara canis, is a common and important zoonotic intestinal nematode parasite that infects dogs globally. An effective treatment that kills any pre-patent stages of immature T. canis could additionally reduce or eliminate the development of patent infections that can result in clinical disease in infected dogs and would further reduce environmental contamination of eggs. Two randomized, blinded, GCP-compliant, pivotal laboratory dose confirmation studies were conducted to assess the effectiveness and safety of a new novel combination of lotilaner and milbemycin oxime tablets (Credelio Plus) administered orally to dogs that were experimentally infected with immature (L4 or immature adult [L5]) stages of T. canis.

METHODS

The commercial tablet formulation of Credelio Plus^® was administered in a time frame relative to inoculation with infective eggs. This allowed for effectiveness to be assessed against each specific immature stage of T. canis. In each study, dogs were randomized and allocated to one of four treatment groups. Each treatment group contained ten dogs that had been experimentally inoculated on Day 0 with infective T. canis eggs and then were dosed once on Day 14 or Day 24 using either placebo tablets or Credelio Plus tablets (IP) to provide minimum dosages of 0.75 mg/kg of milbemycin oxime and 20 mg/kg of lotilaner. All dogs were necropsied 5 or 6 days after their respective treatment. At necropsy, all nematodes recovered from the gastrointestinal tract were counted by species and stage.

RESULTS

In both dose confirmation studies using geometric mean worm counts, effectiveness of Credelio Plus was ≥ 98.6% and ≥ 96.8% against L4 larval stage T. canis and immature adult [L5] T. canis in both studies, respectively.

CONCLUSIONS

These studies demonstrated that the Credelio Plus combination tablet administered orally to dogs was highly efficacious against experimental infections with L4 and immature adult [L5] stages of T. canis.

Field study to investigate the effectiveness and safety of a novel orally administered combination drug product containing milbemycin oxime and lotilaner (Credelio® Plus) against natural intestinal nematode infections in dogs presented as veterinary patients in Europe

BACKGROUND

A randomised, blinded, positive controlled, multicentre, Good Clinical Practice-compliant, pivotal field study was conducted to evaluate the effectiveness and safety of a new combination of lotilaner + milbemycin oxime tablets (Credelio^® Plus; Elanco Animal Health) administered orally to client-owned dogs naturally infected with intestinal nematodes.

METHODS

Client-owned dogs presenting to veterinary clinics from households in France, Hungary and Germany were screened for intestinal nematodes. Dogs with an initial positive faecal egg count that was subsequently confirmed with a follow-up faecal examination to demonstrate the presence of naturally occurring mixed or mono-infections with Toxocara canis, Toxascaris leonina, Trichuris vulpis or Ancylostoma caninum were enrolled on Day 0 into the study. Households were randomised in an approximately 2:1 ratio to receive either an investigational product (IP; Credelio Plus tablets) or control product (CP; Nexgard Spectra^® tablets) as treatment. Dogs were administered the IP (n = 278) or CP (n = 117) once on Day 0 at a dose rate of 0.75-1.56 mg/kg bodyweight milbemycin oxime and 20.0-41.5 mg/kg bodyweight lotilaner (IP) or as recommended (CP). Effectiveness of the IP and CP treatments was based on the post-treatment reduction in geometric mean faecal egg counts on Day 8 (range Day 7-10) after treatment as compared to their pre-treatment nematode faecal egg counts.

RESULTS

Geometric mean (GM) faecal egg counts for T. canis, A caninum and T. vulpis were reduced by ≥ 97.2% in the Credelio Plus group and  by ≥ 95.3% in the afoxolaner + milbemycin oxime group. There were insufficient data to calculate a percentage reduction in GM faecal egg counts between Day 0 and Day 8 for T. leonina due to low prevalence. Credelio Plus was well tolerated in this field study. Of the 355 total doses administered, 82.3% were accepted free choice in the IP group compared to 80.8% in the CP group.

CONCLUSIONS

This study demonstrated effectiveness (≥ 97.2% reduction), safety and tablet acceptance of a combination of milbemycin oxime and lotilaner (Credelio Plus) administered orally to dogs with natural intestinal infections of T. canis, A. caninum and T. vulpis.

Clinical, Parasitological, and Serological Follow-Up of Dogs with Sarcoptic Mange Treated Orally with Lotilaner

Canine sarcoptic mange is a highly pruritic and contagious skin disease caused by the mite Sarcoptes scabiei var. canis. This case series describes the clinical, parasitological, and serological follow-up of a cohort of eight adult Saint Bernard dogs with confirmed sarcoptic mange, treated orally with lotilaner. Dogs were evaluated initially and after 14 days and 1, 2, 3, 4, 6, and 12 months for skin lesions, pruritus severity, presence of parasites, and Sarcoptes-IgG levels. A serological indoor allergy panel (IgE) was obtained for seven dogs at day 0 and repeated 12 months later in five dogs to assess potential cross-reactivity between S. scabiei and environmental allergens. Lotilaner was administered to each dog according to the manufacturer's instructions and was repeated after one and two months without any concurrent therapeutic measure or modification of the husbandry conditions. Pruritus ceased after two weeks. The cutaneous score was reduced by 47%, and skin scrapings were negative for all but three animals. All skin scrapings were negative after one month. Lesions were absent after two months. Serological levels decreased gradually, but more slowly than the skin lesions, and two dogs out of six remained positive in the absence of skin lesions or symptoms. All dogs initially tested positive for dust mites and/or storage mites. The IgE titres remained unchanged 12 months later in the five tested dogs. This case report demonstrates the efficacy of lotilaner on scabies in a cohort of infested dogs under natural conditions and the potential antigenic cross-reaction of S. scabiei with house dust and storage mites.

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.