A third consecutive phase III success for AstraZeneca PLC (LSE:AZN, NASDAQ:AZN) tozorakimab in chronic obstructive pulmonary disease (COPD) has reinforced Citi's conviction in the drug's blockbuster potential, though the bank's analysts flagged a minor but notable change in tone from the company's own announcement.
The MIRANDA trial tested a higher-dose, fortnightly regimen of the interleukin-33 (IL-33) inhibitor.
The study met its primary endpoint with statistically significant and clinically meaningful reductions in moderate-to-severe exacerbations (episodes in which symptoms worsen acutely) across former and current smokers, all eosinophil (a type of white blood cell used as an inflammatory marker) levels, and all stages of lung function severity.
The result mirrors the earlier OBERON and TITANIA readouts, which used a once-monthly dose, giving AZ three positive pivotal studies behind the same asset.
Citi said the data supported its $3.5 billion unrisked peak sales estimate, which it risk-adjusts to $3 billion, and identified two sources of potential upside that its current model does not yet capture.
The first is smoking status: the bank's forecasts assume use only in former smokers, who represent around 60% of patients, leaving the current-smoker population as an untapped opportunity that MIRANDA's broader dataset now supports.
The second is market penetration among patients with high eosinophil counts, a subgroup comprising roughly 36% of trial participants, where Citi currently models just 5% uptake.
That figure is deliberately conservative pending full data on how tozorakimab compares against approved biologics Dupixent and Nucala, or late-stage rival Tezspire, in that specific population.
AZ's own guidance points to peak sales of between $3 billion and $5 billion, suggesting the company sees meaningful room above Citi's base case.
One detail, however, tempered the otherwise clean read-across from prior results.
The MIRANDA press release described the trial outcome as "clinically meaningful," stopping short of the word "highly" that featured in AstraZeneca's earlier OBERON and TITANIA announcements, a distinction Citi's analysts noted explicitly, though they stopped short of treating it as a red flag ahead of full data disclosure.
Citi rates the stock 'buy' with a £180 price target, according to MarketBeat.