Ixekizumab (IXE) (Taltz) is a biologic disease-modifying antirheumatic drug (bDMARD) indicated for use in adult patients with active ankylosing spondylitis (AS) who have responded inadequately to, or are intolerant to conventional therapy (CT). CT may involve corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and conventional disease-modifying antirheumatic drugs (cDMARDs) such as sulfasalazine, methotrexate, and leflunomide1, although according to the latest clinical guideline, corticosteroids should not be used as a long-term treatment for AS, and cDMARDs have not shown efficacy in managing AS and are not recommended to be concurrently administered with biologic treatments. The dosage form of IXE is an 80 mg/mL solution in a pre-filled syringe or pen, intended for patients to self-administer subcutaneously. The recommended dose for adult AS patients is an 80 mg injection given every four weeks. Limited data also suggests that some tumour necrosis factor inhibitor (TNFi)-experienced patients with AS may benefit from a 160 mg starting dose. At the sponsor’s submitted price of $1,582.24 per 80 mg dose, the annual cost of IXE is $20,569 in patients with AS, while in patients who started with a 160 mg initial dose, the first-year cost of IXE is $22,151 per patient, followed by $20,569 per patient in subsequent years. IXE was previously reviewed by CADTH in 2016 for the indication of moderate to severe plaque psoriasis, and in 2018 for active psoriatic arthritis in patients with inadequate response to cDMARDs. CADTH Canadian Drug Expert Committee (CDEC) recommended listing IXE for both indications. For moderate to severe plaque psoriasis, CDEC recommended listing with the clinical criteria limiting its use to patients with a documented inadequate response, contraindication, or intolerance to conventional systemic therapies such as methotrexate and cyclosporine, and recommending that treatment should be discontinued if response to treatment with IXE has not been demonstrated after 12 weeks. For active psoriatic arthritis in patients with inadequate response to cDMARDs, CDEC recommended listing with the condition that IXE should provide cost savings for drug plans relative to other biologic treatments reimbursed for the treatment of psoriatic arthritis. The sponsor’s submitted price for IXE was $1,519 per 80 mg dose at the time of the 2016 CADTH Common Drug Review (CDR) submission, and $1,544.82 per 80 mg dose at the time of the 2018 CDR submission.