Tirzepatide (Mounjaro)

Key Messages

• Canada’s Drug Agency (CDA-AMC) recommends that Mounjaro be reimbursed by public drug plans as an add-on to diet and exercise to improve blood sugar control in adults with type 2 diabetes mellitus (T2DM) when combined with metformin, metformin and a sulfonylurea, or metformin and a sodium-glucose cotransporter-2 (SGLT2) inhibitor if certain conditions are met.
• The Canadian Drug Expert Committee (CDEC) determined that Mounjaro demonstrates acceptable clinical value versus glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in adults with T2DM. This determination was enough for CDEC to recommend that tirzepatide be reimbursed. Given that tirzepatide is expected to be an alternative to GLP-1 RAs, such as semaglutide, acceptable clinical value refers to at least comparable value versus this group of drugs.
• Evidence from 3 phase III randomized controlled trials showed that Mounjaro 5 mg, 10 mg, and 15 mg reduced blood sugar levels in adults with T2DM receiving various background therapies compared to semaglutide 1 mg, insulin degludec, and insulin glargine; however, CDEC considered the results for Mounjaro 5 mg to be similar in hemoglobin A1C reduction to semaglutide 1 mg. Evidence from an additional phase III randomized controlled trial demonstrated that the highest tolerable dose of Mounjaro was just as effective as dulaglutide 1.5 mg in reducing major adverse cardiovascular events in adults with T2DM and established cardiovascular disease.
• Evidence from 2 network meta-analyses suggested an improvement in the blood sugar levels and weight between Mounjaro and most of the comparators evaluated. However, the committee noted there was no difference in reduction in blood sugar levels between Mounjaro 5 mg and semaglutide 1 mg; the effects may be similar for 5 mg and 10 mg doses of Mounjaro compared to semaglutide 2 mg, although the results are highly uncertain.
• Mounjaro meets some of the needs identified by patients, including lowering hemoglobin A1C levels and improving weight control. However, CDEC could not conclude that Mounjaro results in fewer side effects or improved quality of life compared to other GLP-1 RAs.
• Mounjaro should only be reimbursed for adults with T2DM according to the criteria used by public drug plans for other GLP-1 RAs and in line with the sponsor’s reimbursement request. Mounjaro should only be covered for patients who would already be covered by the criteria from the public drug plans for other GLP-1 RAs (e.g., semaglutide) currently reimbursed for the treatment of adults with T2DM.
• In addition to the following pre-existing criteria for other GLP-1 RAs, Mounjaro should not be used in combination with other GLP-1 RAs. Mounjaro should only be reimbursed if the cost of Mounjaro 10 mg and 15 mg is reduced and the drug program cost of Mounjaro 5 mg does not exceed semaglutide 1 mg. Important budget impact considerations must also be addressed for health systems to be able to adopt Mounjaro.