AstraZeneca has resumed new patient enrolment in Phase III trials testing the potential of its anti-PD-L1 immunotherapy durvalumab for head and neck cancer.

The US Food and Drug Administration has now lifted the partial clinical hold preventing registration of new patients with head and neck squamous cell carcinoma (HNSCC) in clinical trials testing durvalumab as monotherapy and in combination with tremelimumab or other potential medicines.

The move follows analysis of bleeding events observed as part of the routine safety monitoring of the Phase III KESTREL and EAGLE trials.

The KESTREL trial has already re-opened for new patient enrolment at some clinical study sites, and the EAGLE trial is expected to resume recruitment shortly, without amendments to either protocol, AZ said.

Last month, AZ presented encouraging early data from a Phase I/II trial assessing durvalumab in patients with metastatic/recurrent HNSCC. Data showed that overall response rate was 11 percent in all evaluable patients (n=62) and 18 percent for those with PD-L1-high tumours (n=22). Overall survival was 62 percent and 42 percent in all evaluable patients at six and 12 months, respectively.

On the safety side, the most common adverse events reported in more than 5 percent of patients were fatigue (18 percent), diarrhoea and nausea (8 percent each), pruritus, rash and maculopapular rash (7 percent each). Five patients (8 percent) experienced treatment-related Grade 3-4 AEs.