OPTIMIZING TREATMENT, MINIMIZING RISK: THERAPEUTIC DRUG MONITORING IN HEMATOLOGICAL MALIGNANCIES

Background: The therapeutic landscape of hematological malignancies has expanded rapidly, increasing survival but also exposing patients to pharmacokinetic variability and clinically relevant drug-drug interactions. Therapeutic drug monitoring (TDM) offers a pharmacokinetics-informed strategy to individualize dosing, yet its real-world implementation across drug classes and healthcare settings remains insufficiently characterized. Methods: We conducted an international, cross-sectional online survey (December 2023-February 2024) assessing availability, utilization, and clinical impact of TDM in patients with hematological malignancies. Physicians from multiple specialties reported institutional practices, turnaround times, drug-specific monitoring strategies, and treatment modifications based on TDM results. Results: A total of 209 physicians from 32 countries participated, predominantly from Europe (92%). TDM was widely accessible (97%), mainly performed onsite (79%), and perceived as beneficial by nearly all respondents (99%). Routine TDM was most frequently used for classical agents (methotrexate, cyclosporin A), antifungals, and antibiotics, but substantial interest was reported for targeted therapies, including BCL-2 inhibitors, BCR-ABL tyrosine kinase inhibitors, FLT3 inhibitors, and Bruton tyrosine kinase inhibitors. Treatment was modified based on TDM results by 71% of respondents, with faster turnaround times strongly associated with clinical action. Limited assay availability, delayed reporting, and insufficient clinical evidence were identified as key barriers to broader implementation. Conclusions: TDM is widely available and perceived as clinically useful in the management of hematological malignancies, frequently informing treatment decisions. While firmly established for classical agents and anti-infectives, clinicians express growing interest in extending TDM to targeted therapies. Optimizing turnaround times, expanding assay availability, and integrating pharmacokinetics-informed dosing into clinical trials may further clarify the role of TDM within precision medicine approaches in hematology.