What are the side effects of inotuzumab ozogamicin treatment for patients with acute lymphoblastic leukaemia?

This study aimed to investigate the adverse events of inotuzumab ozogamicin (Besponsa) for treatment of relapsed or refractory acute lymphoblastic leukaemia.

This study concluded that inotuzumab ozogamicin leads to increased liver damage when compared to standard therapy.

Acute lymphoblastic leukaemia (ALL) occurs when white blood cells called lymphocytes are overproduced and become abnormal. Lymphocytes function in fighting infections. The abnormal cells called lymphoblasts can kill normal cells and spread through the body.

Chemotherapy is the standard treatment for ALL. Inotuzumab ozogamicin (IO) is an antibody drug conjugate being used in clinical trials and may be a suitable treatment for relapsed ALL (disease that returns). It works by delivering a toxic drug to the cancer cells to kill them. Trials have shown that IO significantly improved complete remission rates (no sign of active disease) compared chemotherapy. However, it was not known what adverse events (side effects) were associated with IO.  

This study involved 326 patients who had relapsed or refractory (did not respond to treatment) ALL who had previously received treatments that did not work. 51% of patients were treated with IO and 49% of patients were treated with standard chemotherapy. The safety of IO was assessed.

Hepatotoxicities (liver damage) occurred in 51% of the IO group compared to 34% of the standard care group.

Sinusoidal obstruction syndrome (a type of liver damage-SOS) was seen in 13% of the IO group compared to less than 1% of the standard care group.

Of the patients who did not undergo a stem cell transplant (HSCT) before the study: the IO group had a 3% chance of SOS while the standard care group had a 0% chance.

Of the patients who underwent HSCT before the study: the IO group had a 22% chance of SOS while the standard care group had a 3% chance.

At 24 months, patients treated with IO had a 38.9% chance of survival, compared to 28.7% of the standard care group.  

This study concluded that using IO is associated with increased liver damage, especially after HSCT, when compared to standard care. 

Studies on a larger scale need to be carried out. 

This trial was funded by Pfizer, the manufacturer of IO.

Consult your physician about treatment options for ALL.