AstraZeneca PLC (LON:AZN) said its cancer treatment Imfinzi missed its endpoint in a phase III trial on people suffering recurrent or metastatic head and neck cancer.
Survival rates using Imfinzi as a first-line treatment didn't improve compared to current standard treatment, said the FTSE 100 company.
Treatment in combination with another drug also failed to improve survival rates.
In a statement, Dave Fredrickson, executive vice president of AstraZeneca's Oncology Business Unit, said: "Metastatic head and neck cancer is a complex and challenging disease with a poor prognosis.
“While we are disappointed by these results, insights from the KESTREL Phase III trial will advance our understanding and application of immunotherapy across our clinical development programme.
"We will continue to build on the established benefits of Imfinzi in early lung cancer and small cell lung cancer, to bring immunotherapy treatment options to all patients who may benefit."
The drug company added that 750,000 patients were diagnosed with head and neck cancer around the world in 2020 with two-thirds of those in advanced stages with more than half of those treated eventually relapsing.
The KESTREL Phase III trial was conducted in more than 200 centres across 23 countries.
The primary endpoint was OS (overall survival) in patients with high PD-L1 expression in the Imfinzi monotherapy arm.
Imfinzi (durvalumab) is a human monoclonal antibody that binds to PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80, countering the tumour's immune-evading tactics and releasing the inhibition of immune responses, AstraZeneca added.
More than 90% of all head and neck cancers start in the squamous cells that line the mouth, nose and throat and are called head and neck squamous cell carcinomas.