Early Versus Late Stopping of Antibiotics in Adults With High-risk Hematological Malignancies/Receiving Cellular Therapies and Fever

This study is designed to assess the safety, benefits and impacts of early cessation of empiric antibiotics in all fever (both pre-neutropenic (PNF) and neutropenic (NF)) that develops post conditioning or chemotherapy until count recovery in high-risk hematology patients who meet clear inclusion criteria. This is in recognition of the fact that both PNF and NF are often not infective in nature, and that cessation is likely an important and safe approach in both scenarios. Secondly, the patient's pre-neutropenic and neutropenic status is highly fluid and can rapidly change from one to the other (within a day), making strict definitions of neutropenia arbitrary and not particularly useful for implementation in the clinical setting. Furthermore, as a programmatic-type intervention that is embedded in clinical workflow, approaching high-risk patients with fever in a standardized way would enable consistency and inform clear and concise management protocols. Stratification will allow for assessment of each patient sub-group to provide more granular data.

As an Australian first, this study will exploit the full potential of electronic medical record (EMR) systems, embedding all key aspects of the trial including screening, randomization and data collection into standard clinical and EMR workflows. This highly novel and innovative clinical trial methodology has the potential to improve trial efficiency, data quality and transferability between healthcare centers and will systematically evaluate the barriers and enablers of embedded trials (ELSA-EMR).

The study hypothesizes that early cessation of antibiotics in adult patients with high risk fever is safe, acceptable, cost-effective and will minimize an unnecessarily prolonged health care intervention

Inclusion criteria

Adult patients ( ≥18 years) who are receiving either:

• Conditioning chemotherapy for an autologous or allogeneic haematopoietic cell transplant or CAR T cell therapy, OR
• Induction remission chemotherapy for acute leukaemia,

AND develop fever ( ≥38degC) between time of initiation of chemotherapy/conditioning administration and ANC recovery to ≥500 cells/mm3 post the ANC nadir,

AND fever subsequently has settled (<38degC) for ≥48 and <96h hours.

[participants will be stratified into pre-neutropenic (ANC ≥500 cells/mm3) and neutropenic (ANC<500 cells/mm3) strata based on ANC level at 48 hours post fever onset, as per international consensus definition of neutropenic fever]

Exclusion criteria

• - Prolonged fever prior to defervescence (documented daily temperature ≥38.0°C for ≥ 5 days)
• Documented positive blood culture for bacteria since onset of fever episode and prior to randomisation
• Documented other infection (clinically or microbiologically defined) requiring antibacterial treatment
• Grade 2 or higher mucositis (WHO) or neutropenic enterocolitis
• Clinically unstable and/or admission to ICU at time of potential randomization
• Within 28 days of last randomization
• Prior randomization during current chemotherapy/conditioning cycle
• Pregnant or breastfeeding
• Currently being treated for CRS Grade 3 or 4, and/or ICANS Grade 3 or 4 (defined as per ASTCT Consensus Guidelines, Lee et al)