OBJECTIVES:

The objective of this study was to assess the effect of additional CYTOPOINT injections in dogs that had an incomplete response to one injection.

METHODS:

On Day 0, veterinary dermatologists enrolled client-owned dogs with confirmed atopic dermatitis (AD) and a pet owner pruritis score (PVAS) of ≥50 mm. All dogs received an injection of CYTOPOINT (dose #1) according to manufacturer’s instructions and were reevaluated at day 30. Dogs with a PVAS of ≥36 mm at any subsequent visit received another CYTOPOINT injection and were asked to return 30 days later for a total of up to 4 visits (days 0, 30, 60, and 90). Treatment success was defined as a 20-mm reduction in PVAS compared with Day 0. This success threshold was based on initial CYTOPOINT pivotal efficacy studies.

RESULTS:

On day 30, 71/110 [65%] dogs were treatment successes. The other 39 dogs were administered a second CYTOPOINT injection. At the day 60 visit, 23/39 (94/110 [85%] cumulative) were treatment successes. The remaining 16 dogs were administered a third CYTOPOINT injection. On day 90 8/16 (102/110 [93%] cumulative) were treatment successes.

For the 8 dogs that did not achieve treatment success, the mean PVAS score decreased only slightly after the first injection.

CONCLUSIONS: This study was designed to determine a protocol to optimize potential treatment success for Cytopoint in canine patients with AD. Initial pivotal studies showed 69% of patients responded by day 28 consistent with this study’s 65% of patients by day 30. Most dogs with only a partial response to the first injection went on to achieve treatment success with a second or third injection (93%). Dogs receiving CYTOPOINT should have a progress examination after 30 days and receive additional injections if necessary, to optimize treatment success.