The Joint American Academy of Dermatology and National Psoriasis Foundation 2019 guidelines on the treatment and management of psoriasis with biologics state that no evidence-based studies have been conducted to determine the appropriate duration of time between discontinuation of the previous medication and initiation of a biologic. The guidelines suggest assessments should be done on a case-by-case basis considering many factors that include

• treatment being discontinued
• disease severity
• response to previous treatment, and
• expert opinion; some experts will begin administration of the new biologic as soon as it is available; whereas, others may wait 3 to 4 half-lives of the previous therapy before beginning the new biologic.1

The British Association of Dermatologists 2020 psoriasis guidelines for biologic therapies include to consider using a washout period of 1 month or the length of a treatment cycle (whichever is longer) when transitioning between biologic therapies.2

The Transitioning Therapies program consensus published in 2014 recommends to include the use of a washout period if the switch is made due to an adverse event and do not include a washout period if the switch is made due to a lack of efficacy when switching from one biologic therapy to another. Initiation of the second biologic therapy occurs with the usual induction and maintenance dosages.3

There are no specific recommendations on switching from another biologic therapy to ixekizumab for the treatment of psoriasis. 

In the pivotal ixekizumab phase 3 UNCOVER clinical trials, patients who were using biologic therapy discontinued biologic treatment prior to the baseline visit and prior to initiating ixekizumab therapy. Required Washout Periods for Patients Who Switched From Another Biologic Therapy to Ixekizumab in UNCOVER-1, -2, and -3 Clinical Trials lists the required washout periods, which ranged from at least 3 to 6 times the half-life of the product.4

Of all subjects in the 3 pivotal ixekizumab UNCOVER clinical trials, 26% had received prior biologic therapy for the treatment of psoriasis.5

PASI 75 Response at Week 12 in Biologic-Experienced Patients in UNCOVER-1, -2, and -3 Clinical Trials provides 75% improvement from baseline in Psoriasis Area and Severity Index (PASI 75) response rate for patients who switched from a different biologic therapy to ixekizumab in the UNCOVER clinical trials. Examination of previous treatment with a biologic did not identify differences in response to ixekizumab among this subgroup at week 12.5

Package inserts for the respective products suggest caution with concomitant use of biologics. Given the small number of biologic switching studies, a washout period may be warranted if a patient switches from 1 biologic therapy to another.1,3,7 See respective package inserts for infliximab, adalimumab, alefacept, golimumab, ustekinumab, and rituximab.

TALTZ® (ixekizumab) injection, for subcutaneous administration, Lilly

The published references below are available by contacting 1-800-LillyRx (1-800-545-5979).