Early infectious complications among patients treated with induction compared to hypomethylating therapy for acute myeloid leukemia

Fluconazole and levofloxacin prophylaxis are ineffective strategies for preventing infections in acute myeloid leukemia patients undergoing chemotherapy

INTRODUCTION

Acute myeloid leukemia patients are at high risk for infections, which contribute to increased mortality rates of up to 70%. The use of antimicrobial prophylaxis has been shown to significantly lower rates of infection. Therefore, this retrospective study aimed to evaluate the effect of two agents that showed effective results in the literature, levofloxacin and fluconazole, as prophylaxis strategies in AML patients.

METHODOLOGY

A total of 85 AML patients' medical records treated with a 7+3 induction chemotherapy protocol in the Cancer Hospital of Uberlândia from 2017 to 2021 were screened and their data was collected. Within these patients, groups for analysis were created based on whether the acting physician included an antibacterial or antifungal prophylaxis protocol during induction. Contingency tables with χ² and odds ratio tests were realized to verify associations between prophylaxis and infection. Additionally, Kaplan-Meier curves with Cox regression were developed to analyze survival.

RESULTS

The use of prophylaxis with either fluconazole or levofloxacin did not lower rates of infection, as those who with prophylaxis did not demonstrate significant differences when compared to those without (20.3-29.7%, and 12.3-23.3%, respectively). Patients who suffered a bacterial infection during induction were shown to have lower overall survival, with a similar trend seen in fungal infections.

CONCLUSION

Bacterial and fungal infections were associated with higher rates of induction mortality and lower overall survival, and prophylaxis using fluconazole and levofloxacin did not present any significant difference in preventing these infections in this study, contrasting results found in the literature. The individuality of each treatment center should be taken into consideration and future studies should be realized to better determine the most effective methods and agents for prophylaxis.

Impact of treatment intensity on infectious complications in patients with acute myeloid leukemia

BACKGROUND

Infectious complications reflect a major challenge in the treatment of patients with acute myeloid leukemia (AML). Both induction chemotherapy and epigenetic treatment with hypomethylating agents (HMA) are associated with severe infections, while neutropenia represents a common risk factor. Here, 220 consecutive and newly diagnosed AML patients were analyzed with respect to infectious complications dependent on treatment intensity and antifungal prophylaxis applied to these patients.

PATIENTS AND METHODS

We retrospectively analyzed 220 patients with newly diagnosed AML at a tertiary care hospital between August 2016 and December 2020. The median age of AML patients undergoing induction chemotherapy (n = 102) was 61 years (25-76 years). Patients receiving palliative AML treatment (n = 118) had a median age of 75 years (53-91 years). We assessed the occurrence of infectious complication including the classification of pulmonary invasive fungal disease (IFD) according to the EORTC/MSG criteria at diagnosis and until day 100 after initiation of AML treatment. Furthermore, admission to intensive care unit (ICU) and subsequent outcome was analyzed for both groups of AML patients, respectively.

RESULTS

AML patients subsequently allocated to palliative AML treatment have a significantly higher risk of pneumonia at diagnosis compared to patients undergoing induction chemotherapy (37.3% vs. 13.7%, P < 0.001) including a higher probability of atypical pneumonia (22.0% vs. 10.8%, P = 0.026). Furthermore, urinary tract infections are more frequent in the palliative subgroup at the time of AML diagnosis (5.1% vs. 0%, P = 0.021). Surprisingly, the incidence of pulmonary IFD is significantly lower after initiation of palliative AML treatment compared to the occurrence after induction chemotherapy (8.4% vs. 33.3%, P < 0.001) despite only few patients of the palliative treatment group received Aspergillus spp.-directed antifungal prophylaxis. The overall risk for infectious complications at AML diagnosis is significantly higher for palliative AML patients at diagnosis while patients undergoing induction chemotherapy have a significantly higher risk of infections after initiation of AML treatment. In addition, there is a strong correlation between the occurrence of pneumonia including atypical pneumonia and pulmonary IFD and the ECOG performance status at diagnosis in the palliative AML patient group. Analysis of intensive care unit (ICU) treatment (e.g. in case of sepsis or pneumonia) for both subgroups reveals a positive outcome in 10 of 15 patients (66.7%) with palliative AML treatment and in 15 of 18 patients (83.3%) receiving induction chemotherapy. Importantly, the presence of infections and the ECOG performance status at diagnosis significantly correlate with the overall survival (OS) of palliative AML patients (315 days w/o infection vs. 69 days with infection, P 0.0049 and 353 days for ECOG < 1 vs. 50 days for ECOG > 2, P < 0.001, respectively) in this intent-to-treat analysis.

CONCLUSION

The risk and the pattern of infectious complications at diagnosis and after initiation of AML therapy depends on age, ECOG performance status and subsequent treatment intensity. A comprehensive diagnostic work-up for identification of pulmonary IFD is indispensable for effective treatment of pneumonia in AML patients. The presence of infectious complications at diagnosis contributes to an inferior outcome in elderly AML patients.

Infectious complications after intensive chemotherapy with CLAG-M versus 7+3 for AML and other high-grade myeloid neoplasms

Contemporary data on infections after intensive chemotherapy for acute myeloid leukemia (AML) are scarce. Cladribine, high-dose cytarabine, G-CSF, and dose-escalated mitoxantrone ("CLAG-M") may result in higher remission rates than standard-dose cytarabine plus anthracycline ("7 + 3") but may result in more infections. We compared moderate to severe infections occurring up to 90 days after the first induction cycle for AML or other high-grade myeloid neoplasms in patients receiving CLAG-M for newly diagnosed (n = 196) or relapsed/refractory disease (n = 131) or 7 + 3 for newly diagnosed disease (n = 115). For newly diagnosed disease, microbiologically documented infections were more frequent after CLAG-M compared to 7 + 3 (adjusted rate ratio, 1.65 [95% CI, 1.06-2.58]; P = 0.03), with a cumulative incidence of 27.8% and 16.5% by day 90, respectively. Patients receiving CLAG-M for relapsed/refractory disease had the highest cumulative incidence of 50.7%. Bacterial bloodstream infections were the most frequent followed by respiratory tract infections. Among 29 patients (7%) who died, infection was a primary or contributing cause of death in 59%. These data indicate that infections continue to cause substantial morbidity in patients treated for AML, especially those treated for relapsed/refractory disease, and are more common with newer, more myelosuppressive regimens such as CLAG-M. Improved strategies for infection prevention are needed.