AstraZeneca’s £19bn blow as Wainua heart drug fails key late-stage trial Proactive uses images sourced from Shutterstock
AstraZeneca PLC (LSE:AZN, NASDAQ:AZN) shares fell 9.55% in early trading, wiping £19 billion from the company’s valuation, after its Wainua drug failed a closely watched Phase III trial in a form of heart disease.
The drop propelled the stock to the top of the FTSE 100 losers’ list.
The CARDIO-TTRansform trial, run with US partner Ionis, tested Wainua in patients with transthyretin-mediated amyloid cardiomyopathy (ATTR-CM), a progressive and often fatal condition in which misfolded protein builds up in the heart.
The study did not meet its primary endpoint of reducing cardiovascular deaths and recurrent cardiovascular events over 140 weeks compared with placebo.
AstraZeneca said adding Wainua to today’s standard of care, which included a stabiliser treatment for most patients, provided no statistically significant benefit.
In a prespecified subgroup of patients receiving Wainua on its own, fewer events were observed and the result was nominally significant, though no treatment effect was seen in patients already on stabiliser therapy.
The trial was the largest ever run in ATTR-CM, enrolling 1,432 patients across 130 sites in 20 countries.
Full data will be presented at the European Society of Cardiology Congress in August.
Sharon Barr, head of biopharmaceuticals research and development at AstraZeneca, said that although the trial missed its primary objective, the results support greater scientific understanding of treatment approaches for the hundreds of thousands of patients living with the disease worldwide.
The readout was one of three major Phase III catalysts hanging over the stock in the second half, alongside the SERENA-4 trial of breast cancer drug camizestrant and the AVANZAR lung cancer study of Datroway.
Citi, which has a buy rating on the shares, had modelled peak Wainua sales in ATTR-CM of around $6.2 billion, with a 59% probability of success, making it the highest-conviction of the three readouts.
The bank estimated in May that a failure of CARDIO-TTRansform would knock around 2.8% off its discounted cash flow valuation, equivalent to roughly £5.20 off its £181 fair value estimate.
Notably, Citi argued at the time that the roughly 10% fall in AstraZeneca shares from their pre-results highs already exceeded the combined 7% downside it attributed to the failure of all three trials.
Even in a scenario where all three readouts disappointed, the bank calculated a bear-case valuation of £168, still 23% above where the shares were then trading.
The broker’s bull case, assuming success across all three, pointed to a valuation of around £204.