Twice-yearly asthma injection cleared by TGA — the catch is PBS access

What just happened

The Therapeutic Goods Administration has approved depemokimab (brand: Exdensur, GSK) as Australia’s newest biologic for severe asthma — and the distinguishing feature is its dosing schedule. Exdensur is the first anti-IL-5 biologic approved in Australia to be administered just twice a year, every six months.

For context: existing anti-IL-5 biologics in Australia’s therapeutic toolkit — mepolizumab (Nucala), benralizumab (Fasenra), reslizumab (Cinqaero) — require injections every four to eight weeks. Depemokimab does not change what the drug class does. It substantially reduces how often patients need to engage with it.

The approved indications are specific:

• Severe eosinophilic asthma in patients aged 12 and over, uncontrolled on medium-to-high-dose inhaled corticosteroids (ICS) plus an additional controller medication
• Chronic rhinosinusitis with nasal polyps inadequately controlled by systemic corticosteroids or surgery

This is not a drug for mild-to-moderate asthma. It is a biologic for the tail end of severity — people already on high-dose preventer inhalers and additional controllers who continue having exacerbations. Roughly 200,000 Australians live with severe asthma, with 32,000 hospitalisations and more than 60,000 emergency department presentations recorded in the most recent annual data.

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Both-and

The dosing burden reduction is real and clinically meaningful

Injection burden is a legitimate factor in adherence and quality of life for people managing chronic severe disease. A patient with severe eosinophilic asthma is already navigating multiple preventer medications, a written asthma action plan, regular specialist review, and the background anxiety that comes with knowing a bad week can mean a hospital admission.

Reducing injections from every four to eight weeks to every six months changes the practical texture of managing that disease. Biologic administration typically requires a clinic visit or supervised home administration. For a working parent, a single-carer household, or someone managing care for others alongside their own condition, the difference between 13 clinic visits per year and 2 is not trivial.

Professor Jo Douglass, respiratory physician at the University of Melbourne, described the approval as providing “an additional treatment option for eligible patients” — a measured framing that reflects what the anti-IL-5 class does and what depemokimab adds within it.

The mechanism is not novel: depemokimab binds interleukin-5 (IL-5), the cytokine that drives eosinophil production and subsequent airway inflammation. Anti-IL-5 biologics have robust trial data across the class. What is new is the molecule’s half-life, enabling the twice-yearly schedule. Common adverse events are consistent with the class: upper respiratory tract infection, allergic rhinitis, pharyngitis, arthralgia.

The PBS gap is the story that matters right now

TGA approval is regulatory clearance — confirmation that the drug meets Australian safety and efficacy standards required to be sold here. It is the necessary first step. It is not access.

Depemokimab is not listed on the Pharmaceutical Benefits Scheme. GSK is in ongoing negotiations with the government for PBS subsidy. Until that listing is confirmed, the drug is available only via private prescription at a cost likely in the thousands of dollars per dose — comparable to pre-PBS pricing of other biologics in the class.

This is not unique to depemokimab. It is the recurring gap in Australia’s drug approval architecture between TGA clearance and patient access. The two processes are separate, run in parallel, and do not synchronise. Approval headlines frequently precede accessible treatment by 12 to 24 months.

For the GP fielding a patient question about whether they can switch to the twice-yearly biologic: not yet, unless enrolled in a trial or able to fund private prescription. For the respiratory physician managing patients on existing anti-IL-5 agents that are controlling disease well: there is no clinical basis to switch before PBS listing establishes accessible cost parity.

Who this actually reaches today

Current practical access sits with: clinical trial participants, patients whose specialists can access compassionate supply pathways, and patients who can absorb private costs. The patients most burdened by severe eosinophilic asthma — often those with least flexibility for frequent clinic visits, those most likely to benefit from reduced injection scheduling — will be the last to access this drug if PBS listing does not follow promptly.

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My two cents

For a patient managing severe asthma, a headline announcing “new injection — twice a year” creates an entirely reasonable expectation that something is about to change for them. The honest answer is: the therapeutic case is sound, the drug is now legally available in Australia, and the next step is PBS listing, for which there is no confirmed timeline.

If you are currently on a biologic controlling your disease, depemokimab’s arrival on the approved list is not a signal to switch. It is a signal that the anti-IL-5 class now has a new option with a substantially lighter injection schedule — one that may become accessible via the PBS and is worth knowing about for future planning conversations with your specialist.

The PBS timeline is the needle to watch.

Verdict: maybe — a genuine advance in dosing convenience for severe eosinophilic asthma, with a robust mechanism and clear indication. Clinical access currently limited to trials and private prescription; PBS listing is the event that changes the calculus for most patients.

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Sources cited

1. Sheppeard A. TGA clears twice-yearly biologic for severe asthma. The Medical Republic, 30 July 2026. https://www.medicalrepublic.com.au/tga-clears-twice-yearly-biologic-for-severe-asthma/127764