Due to positive results, AstraZeneca will end its Phase III ASCEND trial of Calquence (acalabrutinib) in previously-treated patients with chronic lymphocytic leukaemia (CLL) early.

The early finish comes after the drug was found to significantly increase the time patients live without disease progression compared to a combination regimen of rituximab and idelalisib or bendamustine.

The ASCEND (ACE-CL-309) study evaluated the efficacy of Calquence in previously-treated patients with CLL and is the first of two Phase III CLL trials expected to read out in 2019.

The drug is an inhibitor of Bruton tyrosine kinase (BTK), which binds covalently to BTK, thereby inhibiting its activity. In B-cells, BTK signalling results in activation of pathways necessary for B-cell proliferation, trafficking, chemotaxis, and adhesion.

José Baselga, executive vice president, R&D Oncology said: “Calquence is the first BTK inhibitor to show benefit in a Phase III trial as a monotherapy compared to current standard-of-care combinations used in relapsed or refractory chronic lymphocytic leukaemia. We look forward to presenting detailed results at a forthcoming medical meeting.”

CLL is the most common type of leukaemia in adults, accounting for approximately one in four new cases of leukaemia in the US, with the average age at the time of diagnosis being approximately 70 years of age.

Calquence is currently approved for the treatment of adults with relapsed or refractory mantle cell lymphoma (MCL) in the US, Brazil, the UAE, and Qatar, and is being developed for the treatment of CLL and other blood cancers.