Australia registers Mounjaro for type 2 diabetes, listing six pen strengths

Mounjaro, the brand name for tirzepatide, has been registered in Australia for the treatment of adults whose type 2 diabetes is not sufficiently controlled. The Therapeutic Goods Administration (TGA) approved the application on December 22, 2022, and registered the medicine the next day, December 23, 2022 ^[1]. The submission was classified as a new chemical entity, and the sponsor is Eli Lilly Australia Pty Limited ^[1].

The approved wording covers use as an adjunct to diet and exercise, as monotherapy when metformin is not tolerated or is contraindicated, or in addition to other medicines for type 2 diabetes ^[1]. That means the Australian label describes a diabetes indication, not a weight-management one; no weight-loss use appears in the registration notice ^[1].

The listing covers six strengths of tirzepatide 0.5 mL solution for injection in pre-filled pens: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg. Each strength has its own entry on the Australian Register of Therapeutic Goods, with the 2.5 mg pen carrying a separate number from the other five ^[1]. The medicine is classed as a prescription product in Australia ^[1].

Tirzepatide is described by the TGA as a long-acting dual GIP and GLP-1 receptor agonist. It is a 39-amino acid peptide with a C20 fatty diacid moiety that allows it to bind to albumin and stay in the body longer. The TGA says receptors for both hormones are found on pancreatic alpha and beta endocrine cells, as well as in the brain, heart, blood vessels, immune cells, gut and kidney, with GIP receptors also present on fat cells. Tirzepatide binds with high affinity to both receptors; its activity at the GIP receptor is similar to the natural GIP hormone, while its activity at the GLP-1 receptor is lower than natural GLP-1 ^[1].

The TGA said the decision rested on quality (chemistry and manufacturing) data, nonclinical data on pharmacology and toxicology, clinical data on pharmacology, safety and efficacy, and a risk management plan submitted by the sponsor. The agency judged the benefit-risk profile favorable for the approved use ^[1].

Why it matters for patients

Tirzepatide is a different molecule from semaglutide, the active ingredient in Ozempic, Wegovy and Rybelsus. The Australian registration therefore does not extend to those products, and it does not change how any GLP-1 or dual-agonist medicine is regulated or sold in the United States ^[1].

The registration is specifically for type 2 diabetes in adults, with the label tying use to diet and exercise and to whether metformin is tolerated or appropriate ^[1]. People taking these medicines for other reasons would be looking at a different regulatory pathway than the one described in this decision ^[1].

Six strengths are registered rather than one, which gives Australian prescribers a defined set of pen options to work from ^[1]. The notice does not describe dosing schedules, step-up timing or which patients should start at which strength.

What happens next

The TGA page does not say when Mounjaro will reach Australian pharmacies, what it will cost, or whether it will be subsidized under Australia's Pharmaceutical Benefits Scheme. Those details have not been reported ^[1]. The notice also does not address availability, pricing or insurance coverage outside Australia ^[1].

One timing detail is worth noting: the decision date and the registration date differ by one day, December 22 and December 23, 2022 ^[1]. Both dates appear on the same TGA product record.