Evaluating infection risk in patients with blood cancers treated with new targeted therapy drugs

This study aimed to investigate the risk of infections in patients with blood cancers who were treated with new targeted therapy drugs. 

This study concluded that a high proportion of these patients experienced severe infections. However, the infection risk was similar to that of chemotherapy. 

Treatments for blood cancers such as leukemia and lymphoma have been improved in recent years. New targeted therapies and immunotherapies have increased anti-tumor effectiveness and reduced toxicities compared to standard chemotherapy regimens. 

New treatments include monoclonal antibodies such as obinutuzumab (Gazyva), ofatumumab (Arzerra), brentuximab vedotin (Adcedris), nivolumab (Opdivo), and pembrolizumab (Keytruda), targeted therapies such as ibrutinib (Imbruvica), acalabrutinib (Calquence), idelalisib (Zydelig), and venetoclax (Venclexta). 

These medications have been shown to reduce the ability of the immune system to protect against infection. However, how common are infections in patients with blood cancers treated with these new medications is still not clear.

This study involved 458 patients with leukemia or lymphoma who were treated with targeted and immune therapies. The occurrence of infections was evaluated over an average follow-up of 17 months.

The occurrence of severe infections was 23% in all patients. The occurrence of infections was higher during the first 3 to 6 months of treatment and then decreased. The highest occurrence of infections was associated with ibrutinib treatment, followed by idelalisib, and brentuximab. 

54% of infections were bacterial. 19% of infections were viral (such as respiratory, including COVID-19). 6% of infections were invasive fungal infections (IFI). IFIs were mainly seen in patients with chronic lymphocytic leukemia (CLL) who were treated with ibrutinib.  

Significant risk factors for severe infection were severe lymphopenia (a very low number of lymphocytes, a type of white blood cell), combined treatment versus single-agent treatment, and previous rituximab (Rituxan) treatment. Infection-related mortality was 6%. In 22% of patients with severe infections, targeted drug treatment was stopped completely. In 77% of cases, treatment was temporarily stopped. 

This study concluded that a high proportion of patients with leukemia/lymphoma treated with new targeted therapies experienced severe infections. However, this occurrence is similar to that of standard chemotherapy regimens. 

This study was based on medical records data. Information might have been missing. Other medical conditions may increase the risk of infections, which were not taken into account.