Infection Prevention in Chronic Myeloid Leukemia

Understanding CML-Specific Infection Risk

CML patients do not develop hypogammaglobulinemia, which characterizes CLL and leads to recurrent sinopulmonary infections from encapsulated bacteria, such as Streptococcus pneumoniae and Haemophilus influenzae, according to the National Comprehensive Cancer Network 1
Patients with refractory disease after multiple TKI failures may develop marrow dysfunction, as noted by the Praxis Medical Insights: Practical Summaries of Clinical Guidelines 1

The American Society of Hematology recommends no antimicrobial prophylaxis for patients in chronic phase receiving TKI monotherapy, as stated in Blood Reviews 2, 3, 4
No antibacterial prophylaxis is recommended for CML patients on TKI therapy, according to Blood Reviews 4
No antifungal prophylaxis is recommended for Candida, Aspergillus, or Pneumocystis, as noted by Blood Reviews and the Journal of the National Comprehensive Cancer Network 4, 5
No antiviral prophylaxis is recommended for HSV/VZV, according to Blood Reviews 3, 4
No CMV monitoring is recommended for CML patients on TKI therapy, as stated in Blood Reviews 4

The Centers for Disease Control and Prevention recommends administering standard vaccinations using killed viral agents only, including pneumococcal vaccine, influenza vaccine, herpes zoster vaccine, and COVID-19 vaccination, as noted by Blood Reviews 2
Live virus vaccines should be avoided in all CML patients on active therapy, according to Blood 6

The National Comprehensive Cancer Network recommends considering targeted prophylaxis only when additional risk factors are present, such as hepatitis B prophylaxis, pneumocystis prophylaxis, and HSV/VZV prophylaxis, as stated in Blood Reviews and the Journal of the National Comprehensive Cancer Network 4, 5, 7
Hepatitis B prophylaxis should be initiated if patients are HBsAg positive before starting TKI therapy, according to Blood Reviews 4
Pneumocystis prophylaxis should be considered only if patients are receiving concomitant corticosteroids, as noted by the Journal of the National Comprehensive Cancer Network and Praxis Medical Insights: Practical Summaries of Clinical Guidelines 5, 7

The American Society of Hematology recommends considering fluoroquinolone prophylaxis during the neutropenic period if the absolute neutrophil count is less than 500/μL, as stated in Blood Reviews and Blood 4, 6
Patients should be educated on fever recognition and the need for immediate medical evaluation, according to Blood 6
Myeloid growth factors should be considered on a case-by-case basis if an active infection is present, as noted by Blood 6

The National Comprehensive Cancer Network advises against extrapolating CLL infection guidelines to CML patients, as the evidence provided references CLL/lymphoproliferative disorder guidelines, which address a fundamentally different patient population with severe immune dysfunction, as stated in Blood Reviews and Praxis Medical Insights: Practical Summaries of Clinical Guidelines 1, 2, 3, 4
TKI therapy should not be delayed due to infection concerns, as TKIs are not significantly immunosuppressive and the mortality benefit far outweighs minimal infection risk, according to the American Society of Hematology 2, 3, 4
Irradiated blood products should not be used routinely, as this is only necessary for patients previously treated with purine analogs or undergoing transplantation, as noted by Blood 6
Drug-drug interactions should be monitored if antiviral therapy becomes necessary, as nirmatrelvir/ritonavir interacts with TKIs through CYP3A4 inhibition, potentially requiring TKI dose adjustment or alternative antivirals like remdesivir, according to Blood Reviews 2

Pregnancy does not increase infection risk in CML, as stated in Blood 8
Standard hygiene and hand-washing practices should be maintained, according to Blood 8