PK and Safety Study of Natroba Topical Suspension 0.9% in Subjects 1 Month to 3 Years 11 Months of Age With Scabies

A population of approximately 50 pediatric subjects will be enrolled to assess the PK of spinosad and benzyl alcohol for 3 hours following a single, full-body topical application (open label) on a single in-clinic visit (Day 1, or Day 2 if screening only on Day 1). There will be approximately 50 subjects ages 1 month to 3 years 11 months of age enrolled with the goal of completing approximately 16 subjects. With assistance from a caregiver, Natroba will be applied over the entire body from the neck down to the toes (including the soles of the feet) and to the hairline, temples, forehead and possibly the scalp (if a scabies infestation is present on the scalp). The open-label Investigational Product (IP) will remain on the skin for at least 6 hours before removing the IP by gentle washing. The subjects will stay in the clinic until the 3-hour procedures are completed. Blood draws will be taken at 0 hours just prior to treatment, and then at 0.5 and 3.0 hours post-treatment. Heel sticks are likely to be the mode of blood collection for children less than 2 years of age. A ±5-minute time window will be allowed for all post-treatment blood samples. Removal of IP can occur by the caregiver at home after it has been on the skin for at least 6 hours before bathing the child. Safety will be assessed with adverse events (AEs), general skin and eye irritation assessments, and pre-dose and pre-discharge laboratory evaluations. Following the sample collections subjects will be released from the clinic and directed to their primary care physician for follow-up. Subjects will be provided scabies medications upon discharge to dispense to family members. These include 5% Permethrin for those in the household that are less than 4 years of age and Natroba for those in the household 4 years of age and older. Subjects who terminate early will not be given these medications to dispense to family members.

Natroba (spinosad) Topical Suspension, 0.9% w/w applied by a parent/guardian in a single, full-body topical application from the neck down to the toes (including the soles of the feet) and to the hairline, temples, forehead and possibly the scalp (if a scabies infestation is present on the scalp).

A blood draw will be taken from subjects just before spinosad application (t=0) and then at 0.5 and3.0 hours. The following PK parameters will be calculated for spinosad (spinosyn A and spinosyn D) and benzyl alcohol in each subject: Cmax, Tmax, and Area Under the Curve (AUC) 0-12h.

Safety assessments include monitoring of AEs on study Day 1 or Day 2, general skin and eye irritation assessment on Day 1 or Day 2, laboratory assessments on Day 1 or Day 2, prior medications, and concomitant medications on Day 1 (and Day 2, if applicable). Smaller laboratory blood samples will be collected pre-dose and 12-hours post-dose prior to discharge.