US regulators have awarded Breakthrough Therapy Designation to Janssen Biotech and partner Pharmacyclics' cancer pill ibrutinib.

Ibrutinib targets and selectively inhibits an enzyme called Bruton’s tyrosine kinase (BTK), a key mediator of at least three critical B-cell survival mechanisms. These multiple actions allow BTK to direct malignant B-cells to lymphoid tissues, giving them access to a microenvironment necessary for survival.

The US Food an Drug Adminstration has assigned ibrutinib 'breakthrough' status specifically as a monotherapy for the treatment of two B-cell malignancies: relapsed or refractory mantle cell lymphoma (MCL; in patients who have received prior therapy) and Waldenström’s macroglobulinemia (WM).

Welcoming the move, Paul Stoffels, Chief Scientific Officer and Worldwide Chairman, Pharmaceuticals, at J&J, said the firm is "committed to realising the full potential of ibrutinib for patients with mantle cell lymphoma, Waldenström’s macroglobulinemia, as well as other B-cell malignancies, and will work with Pharmacyclics and the FDA to ensure the clinical development program for ibrutinib continues to move forward as quickly as possible.”

A regulatory filing for ibrutinib in MCL is expected before the end of this year, while discussions with the FDA about filing in WM are ongoing, J&J said.

Though the implications of the Designation "cannot be determined at this time", Janssen and Pharmacyclics are working with the FDA to determine any potential implications to the ongoing and planned developmental pathway, the groups noted.

Quicker development

Breakthrough Therapy Designation was enacted as part of the 2012 FDA Safety and Innovation Act, to help accelerate development timelines for potential new medicines for serious or life-threatening diseases when preliminary clinical evidence indicates a "substantial improvement over existing therapies on one or more clinically significant endpoints.”

US Democratic Senator Michael Bennet previously said the inclusion of the "breakthrough" provision in the Act would provide the flexibility "to allow home-run treatments that show great promise early can reach patients more quickly".

"It also strikes a careful balance between providing regulatory certainty for developers of these breakthrough treatments and maintaining the level of drug safety and efficacy patients expect and deserve," he stressed.

The first such designations were awarded by the US Food and Drug Administration to two cystic fibrosis treatments from Vertex Pharmaceuticals just last month.