Outcomes of blinatumomab in patients with minimal residual disease B-cell acute lymphoblastic leukemia

This study aimed to investigate if blinatumomab was an effective treatment in patients with minimal residual disease B-cell precursor acute lymphoblastic leukemia. 

This study concluded that complete minimal residual response during blinatumomab treatment can be a potentially curative option in these patients.  

Minimal residual disease (MRD) is a small number of leukemic cells that remain after treatment. It is the main cause of relapse in leukemia. MRD is the strongest predictor of relapse in B-cell precursor acute lymphoblastic leukemia (BCP-ALL).  

Blinatumomab (Blincyto) is used as a second-line treatment for relapsed ALL. It is an immunotherapy that triggers the immune system to target cancer cells. It is commonly used in patients with relapsed ALL. However, it was unknown if blinatumomab was effective in patients with MRD BCP-ALL.  

This study involved 110 adult patients with BCP-ALL in remission with MRD after chemotherapy. Patients received blinatumomab treatment daily for up to 4 six-week cycles (4 weeks of continuous treatment, 2 weeks off). 74 patients received allogeneic stem cell transplant (HSCT) in complete remission. Patients were followed for an average of 59.8 months.

The average survival was 36.5 months. The survival rate at 5 years was estimated to be 43%.

88 patients achieved a complete MRD response after blinatumomab. The average survival was not reached (longer than) at the end of follow-up for complete MRD responders compared to 14.4 months for MRD non-responders.   

After blinatumomab and HSCT, the average survival was not reached for the MRD responders compared to 16.5 months for the MRD non-responders. 

This study concluded that complete MRD response during blinatumomab treatment is curative in patients with BCP-ALL. It was also concluded that although HSCT after blinatumomab may be beneficial in some patients, long-term survival without HSCT is also possible. 

This study did not have a comparison group. Further studies are needed.