AstraZeneca and group member Acerta Pharma say acalabrutinib is being given a priority review by the US Food and Drug Administration for mantle cell lymphoma (MCL), hot on the heels of it having been assigned a breakthrough designation by the regulator.

MCL is an aggressive B-cell non-Hodgkin lymphoma with poor prognosis, accounting for around 3 percent to 6 percent of new NHL cases in Western countries each year.

AZ describes acalabrutinib as a “highly selective, potent, covalent inhibitor of Bruton tyrosine kinase (BTK) with minimal off-target activity observed in preclinical trials”, in development for the treatment of multiple B-cell and other cancers.

In MCL approval for the drug is being sought to treat patients with relapsed/refractory disease who have received at least one prior therapy, on the back of data from the Phase II ACE-LY-004 clinical trial, which are to be presented at a medical meeting later this year.

The fact that the drug has now been awarded both breakthrough and priority designations signals the regulator’s belief that, if successful, it has the potential to offer patients a significant improvement in the treatment of the disease.

“FDA’s acceptance of the acalabrutinib application and Priority Review illustrates the impact it could have on patients with relapsed or refractory mantle cell lymphoma as we work to bring this potential medicine to those in need as quickly as possible,” noted Sean Bohen, executive vice president, Global Medicines Development, and chief medical officer at AZ.

In 2015 AZ announced a $4-billion for a majority stake in Acerta, paying $2.5 billion upfront with an unconditional $1.5 billion to be handed over either on receipt of the first regulatory approval for acalabrutinib in the US, or the end of 2018, whichever comes first.