Acalabrutinib in CLL and MCL Patients Subjected to Allogeneic Hematopoietic Stem Cell Transplantation (alloSCT)

In this phase II multicenter trial we plan to use acalabrutinib before and after allogeneic hematopoietic stem cell transplantation (alloSCT) with reduced intensity conditioning (RIC) in patients with refractory/relapsed MCL and CLL with poor prognostic factors. Acalabrutinib will be used before alloSCT with the intention to reduce tumor burden and after transplant to augment disease control. Since chronic GvHD is mediated by activated B lymphocytes, we also speculate that the drug as a BTK inhibitor may reduce the severity and incidence of chronic graft-versus-host disease (GvHD) after alloSCT, as it was shown for ibrutinib. Best response to therapy and safety issues will be the primary target of this small trial (25 transplanted pts).TEAE and SAE of acalabrutinib in patients after alloSCT that was not previously assessed. We hypothesize that this treatment will improve the efficacy of the alloSCT - this issue will be addressed by serial minimal residual disease (MRD) evaluation in peripheral blood and bone marrow. This treatment strategy could significantly improve the outcome of poor prognosis MCL and CLL patients.