
Sanofi-owned Aventis Pharma has received approval for its type 1 diabetes (T1D) drug, Tzield (teplizumab), from the UK Medicines and Healthcare products Regulatory Agency (MHRA).
This authorisation makes the disease-modifying monoclonal antibody (mAb) the first immunotherapy to be approved in the UK for T1D – a feat particularly notable for British patients, who have traditionally had to rely on insulin therapy. Tzield is administered by intravenous (IV) infusion once daily for two weeks during treatment.
The anti-CD3 mAb’s go-ahead from the MHRA follows its approval from the US Food and Drug Administration (FDA) in 2022. This decision was based on its ability to delay stage three T1D onset, when noticeable symptoms of the disease develop, by up to three years.
By preventing progression to stage three, Tzield can help patients remain off insulin therapy for a longer period, though it must be administered to patients in early stages of the disease to be effective.
The mAb acts by binding to the CD3 receptor, which deactivates the cellular cascade associated with autoreactive T-cell activation. This subsequently slows the progression of this autoimmune disease.
The National Institute for Health and Care Excellence (NICE) is currently evaluating Tzield’s benefit-cost ratio, which will form its decision on whether the drug should be available through the National Health Service (NHS). The agency is expected to make this call by 26 November 2025.

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By GlobalDataSanofi acquired the rights to Tzield through its $2.9bn acquisition of biotech Provention Bio in 2023, which built on the previous co-promotion deal focused on the delivery and marketing of the mAb in the US.
The drug, which is now approved in the US, UK, Canada, Israel, UAE, Kuwait and Saudi Arabia, is set to reach blockbuster status by 2026 – with GlobalData analysts forecasting that it will hit sales of $3.8bn by 2031.
GlobalData is the parent company of Pharmaceutical Technology.
However, concerns have been raised over the drug’s accessibility, as not all individuals living in the regions where Tzield is approved have access to testing. This has led TrialNet Hub to call for the tackling of treatment inequality in this patient population.
Meanwhile, in the broader T1D market, Tzield could soon face stiff competition from other disease-modifying late-stage assets such as Vertex Pharmaceuticals’ cell therapy zimislecel (VX-880), which is currently in Phase III trials. The drug has previously been granted fast-track designation by the FDA.
Another potential competitor for Sanofi is Eli Lilly’s star weight loss drug, Mounjaro (tizepatide). The GLP-1/GIP agonist, which brought in $5.2bn in Q2 for the pharma, is also being investigated in overweight or obese patients with T1D, with the trial expected to conclude in 2027.
Meanwhile, a GlobalData report on the wider T1D market estimates that the indication’s value will inflate at a compound annual growth rate (CAGR) of 13.3%, reaching sales of $9.91bn by 2033.