"While the results from the MYSTIC trial for progression free survival in first-line Stage IV non-small cell lung cancer compared with standard of care are disappointing, the trial was created to assess overall survival and we look forward to evaluating the remaining primary endpoints of overall survival for both mono- and combination therapy", AstraZeneca's chief medical officer Sean Bohen commented in the statement.
One of AstraZeneca's big hopes, a combo of its new I-O med with another experimental cancer drug, has missed a key primary endpoint in first-line lung cancer patients.
AstraZeneca said the trial will continue to assess two additional primary endpoints of overall survival for Imfinzi monotherapy and overall survival for the Imfinzi plus tremelimumab combination. Results on whether the combination actually extends people's lives are expected in the first half of 2018.
Given that the focus around AstraZeneca is on its pipeline, the first half results played second fiddle this morning. Revenue fell amid declining sales of blockbuster drugs Crestor and Seroquel XR, which lost patent protection in the United States a year ago.
However, the Anglo-Swedish pharma group slashed its costs during the period which meant pre-tax profits came in more than 50% higher than the same period previous year at US$1.07bn. The pharmco's core earnings per share meanwhile climbed six percent to $0.87.
The company kept its interim dividend of 90.0 cents per share unchanged.
Analysts at Jefferies said in a note this morning: "We have modeled $5.1 billion peak sales around Mystic, but heavily risk-adjusted: We now model around $3.3 billion in peak sales for durvalumab in metastatic NSCLC and around $1.8 billion for tremelimumab, which is primarily predicated on the outcome of Mystic".
The trial featured an immunotherapy drug, which AstraZeneca hopes will be able to be used as an alternative to chemotherapy in the treatment of non-small cell lung cancer in future, but results were disappointing.More news: Barbara Sinatra Dead: Philanthropist and Widow of Frank Sinatra Dies at 90
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Franklin has the drugmaker as a "buy" with a (perhaps optimistic) target price of £55.
The scale of the sell-off reflects the importance attached by investors and analysts to MYSTIC and the first-line NSCLC indication, given that AZ reported another trial in May showing that Imfinzi improved PFS in second-line NSCLC.
"As a secondary endpoint, although not formally tested, Imfinzi monotherapy would not have met a pre-specified threshold of PFS benefit over SoC in this disease setting", the companies added.
Analysts reckon Tagrisso could have peak sales in excess of US$3bn a year.
In the US, AstraZeneca said product sales were down 28% to USD3.01 billion from the year before, while sales in Europe also declined by 8.0% to USD2.72 billion.
AstraZeneca chief executive Pascal Soriot described the move as an "exciting step" with "a company that shares our passion for science to deliver new medicines for cancer patients".
Shares lost 15.7% at the open to £43.11.