AstraZeneca has reported that the KESTREL Phase III trial of Imfinzi (durvalumab) failed to meet the primary endpoint in the first-line treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) whose tumours expressed high levels of PD-L1.
A human monoclonal antibody, Imfinzi attaches to PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80, thereby countering the immune-evading tactics of tumour and releasing the immune response inhibition.
The randomised, open-label, multi-centre, global trial analysed Imfinzi plus a second immunotherapy, tremelimumab, as compared with the EXTREME treatment regimen (cetuximab with cisplatin or carboplatin plus 5-fluorouracil), a standard of care treatment.
It was carried out at over 200 centres across 23 countries, including in the US, Europe, South America and Asia.
OS in patients with high PD-L1 expression in the Imfinzi monotherapy arm was the trial’s primary endpoint.
A key secondary endpoint of the trial included OS in ‘all-comer’ patients treated with Imfinzi plus tremelimumab.
Results from the trial showed that Imfinzi did not improve overall survival (OS) and as such failed to meet the primary endpoint.
Furthermore, Imfinzi plus tremelimumab did not demonstrate an OS benefit in ‘all-comer’ patients.
AstraZeneca Oncology Business Unit executive vice-president Dave Fredrickson said: “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 company noted that the safety and tolerability profiles for Imfinzi as a monotherapy, as well as with tremelimumab, were consistent with the earlier trials.
Last March, AstraZeneca reported that high-level results from the final analysis of the Phase III CASPIAN trial confirmed a sustained, clinically meaningful overall survival (OS) benefit of its cancer treatment drug Imfinzi.