Pharmacyclics initiates treatment in Phase I lymphoma trial

US-based pharmaceutical company Pharmacyclics has initiated treatment in a Phase I dose-escalation study to evaluate the safety and tolerability of PCI-32765, an orally available, selective inhibitor of Bruton’s tyrosine kinase, or Btk, as a potential treatment for patients with relapsed or refractory B-cell non-Hodgkin’s lymphoma.

This is said to be the first Btk selective inhibitor to be tested in humans, and is Pharmacyclics’s fourth product in clinical development.

This Phase I study is evaluating the safety and pharmacokinetics of PCI-32765 in patients with refractory B-cell non-Hodgkin’s lymphoma using a 28-day dose-escalation design.

The study is also utilizing a pharmacodynamic assay developed by Pharmacyclics to directly assess Btk drug occupancy. Preliminary results from the Phase I trial shows good patient tolerability under conditions of Btk-drug occupancy with potent bioactivity in targeted cell populations derived from the B-cell lymphoma patients.

Ranjana Advani, principle investigator of Phase I clinical trial, said: Despite recent success with biologics in the treatment of B-cell non-Hodgkin’s lymphoma, there is still a large group of patients that do not respond to therapy or who experience recurrence. A drug that could not only have an impact on this patient group, but also be delivered orally would represent a significant step forward in the treatment of this disease.