AstraZeneca’s blood cancer treatment, Calquence, failed to improve survival rates and prevent lung failure in patients hospitalised with symptoms of Covid-19, the drugmaker said, citing results from mid-stage trials.

The company called the outcome “disappointing”. It said its other efforts to combat the pandemic — a possible vaccine developed with Oxford University, and an experimental antibody-based Covid-19 treatment — were not affected.

Covid-19 patients with severe symptoms including pneumonia are believed to suffer from an overreaction of the immune system known as cytokine storm, Reuters reported.

Results from the trials will not impact approved indications or pending approvals for Calquence in patients with blood cancers, the British company said.