The US Food and Drug Administration (FDA) has approved AstraZeneca’s Calquence (acalabrutinib) for chronic lymphocytic leukaemia (CLL) and small lymphocytic lymphoma (SLL).

The company says that the approval, indicated for adult patients, was based on positive results from the interim analyses of two Phase III clinical trials, ELEVATE-TN in patients with previously untreated CLL and ASCEND in patients with relapsed or refractory CLL.

The trials found that the drug in combination with obinutuzumab demonstrated a statistically-significant and clinically-meaningful improvement in progression-free survival (PFS) when compared with the chemotherapy-based combination of chlorambucil and obinutuzumab, thus meeting its primary endpoint.

Further, across both trials, the safety and tolerability of Calquence were consistent with its established profile, with full results of the interim analysis of the ELEVATE-TN trial to be presented at the upcoming American Society of Hematology congress.

The approval is good news for patients, as “Tolerability remains an issue in the current treatment landscape of chronic lymphocytic leukaemia, which may require ongoing therapy for many years” explained Dr Jeff Sharman, director of Research at Willamette Valley Cancer Institute

He continued, “In the ELEVATE-TN and ASCEND trials comparing Calquence to commonly used treatment regimens, Calquence demonstrated a clinically meaningful improvement in progression-free survival in patients across multiple settings, while maintaining its favourable tolerability and safety profile.”

Calquence is an inhibitor of Bruton tyrosine kinase (BTK), which bonds 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. The treatment was initially granted Breakthrough Therapy Designation (BTD) in the US, a system designed to accelerate the development and regulatory review of new medicines that are intended to treat a serious condition, and that have shown encouraging early clinical results

CLL is the most common type of leukaemia in adults, with an estimated 191,000 new cases globally and 20,720 new cases in the US annually, and prevalence that is expected to grow with improved treatment.