Although not formally tested, durvalumab monotherapy would not have met a prespecified threshold of PFS benefit compared with chemotherapy in this patient population, according to an AstraZeneca-issued press release.
The Phase III study - which is looking at how two of its lead IO drugs, Imfinzi and tremelimumab, work together in non-small-cell lung cancer patients - failed to meet the primary endpoint of improving progression-free survival compared to chemotherapy - the current standard of care.
AstraZeneca along with its global biologics R&D research arm MedImmune announced that their immune-oncology combo-treatment for non-small cell lung cancer, or NSCLC, did not meet the primary endpoint in a late-stage study.
It said to expect takeover talk to crop up today on the failure and to see its shares down by around 10% to 15%.More news: US expresses concern over India-China standoff
Soriot declined to comment directly on what he described as "rumours" on Thursday, although company insiders said he would have had to make a statement if he had firm plans to leave. He didn't offer the firmest of denials, but said he was "committed" to AstraZeneca and was not a "quitter". The pharmco's core earnings per share meanwhile climbed six percent to $0.87.
However, I think the company has long term investment potential.
Bristol-Myers Squibb famously learned that lesson the hard way, pushing to test its flagship checkpoint inhibitor Opdivo (nivolumab) in lung cancer patients with 1% or greater PD-L1 expression.
Durvalumab, which AstraZeneca flagged in 2014 as having annual sales potential of $6.5 billion, is central to its drive into oncology - but it is not the only asset.
AstraZeneca - a relative latecomer in immunotherapy - had been hoping to secure a substantial slice of a multibillion-dollar market by proving its combination could help previously untreated patients with advanced lung cancer.More news: N.Korea could carry out missile test soon
Offsetting the Mystic hit, the company also reported that its Tagrisso lung cancer pill improved progression-free survival in another trial called Flaura, which Soriot said put it on track for eventual sales of more than $4 billion 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.
In a related announcement Thursday, AstraZeneca and Merck signed a deal to develop and market the PARP inhibitor Lynparza for different types of cancer.
"In our view, the group should make every effort to capitalise on their strategic tie-up with Merck announced today and strong progress in the trials for Tagrisso".
Total revenue at the company fell 11 percent to $10,456 million, but operating profit rose 37 percent to $1,842 million.More news: Angkasa says partial eclipse of the moon to occur August 7
AstraZeneca reiterated its guidance for the full year.