Ibrutinib as a salvage treatment after transplant for patients with chronic lymphocytic leukemia

This study aimed to investigate if ibrutinib was safe and effective as a salvage treatment after stem cell transplant in patients with chronic lymphocytic leukemia. 

This study concluded that ibrutinib is safe and effective as a salvage treatment in these patients.  

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a procedure in which a person receives blood-forming stem cells from a genetically similar, but not identical, donor. This is often a sister or a brother, but could be an unrelated donor. Salvage treatment is a treatment used after an initial treatment does not work. 

Ibrutinib (Imbruvica) is a type of targeted therapy called a tyrosine kinase inhibitor (TKI). It is used for B cell cancers like chronic lymphocytic leukemia (CLL). It was unknown if ibrutinib was safe and effective as a salvage treatment after allo-HSCT in patients with CLL. 

This study involved 56 patients with CLL who relapsed after allo-HSCT. The average number of treatments prior to transplant was 3. Ibrutinib was used as a salvage treatment in all patients. The average time between allo-HSCT and ibrutinib treatment was 30 months. 

71% of all patients responded to ibrutinib. Of these patients, 41% achieved a partial response and 30% achieved complete response. At the start of ibrutinib treatment, 10 patients had long-lasting graft versus host disease (GVHD). GVHD is where the transplanted cells attack the healthy cells of the patients. GVHD resolved with ibrutinib treatment.   

72% of patients were alive after 2 years. 50% of patients were alive after 2 years without disease progression. The average survival without cancer progression was 24.26 months.

14 patients stopped ibrutinib treatment. 4 of these stopped treatment because of side effects and 10 due to disease progression. Side effects to ibrutinib involved skin reaction, low blood cell counts, infections, diarrhea, and bone pain.

This study concluded that ibrutinib was safe and effective as a salvage treatment after allo-HSCT in patients with CLL. 

This study included a very small number of participants. Further studies are needed.