Quantification of letermovir in human serum using high-performance liquid chromatography with diode array detection.

Area of Science:

• Analytical Chemistry
• Pharmacology

Background:

• Cytomegalovirus (CMV) infection is a significant risk for allogeneic hematopoietic stem cell transplant (HSCT) recipients.
• Letermovir is approved for CMV infection prophylaxis in adult HSCT recipients.
• Accurate monitoring of letermovir levels is essential for effective prophylaxis and patient management.

Purpose of the Study:

• To develop and validate a simple, rapid, cost-effective, and sensitive high-performance liquid chromatography (HPLC) method for letermovir quantification.
• To establish a reliable analytical tool for therapeutic drug monitoring of letermovir in clinical practice.

Main Methods:

• High-performance liquid chromatography with diode array detection (HPLC-DAD).
• Liquid-liquid extraction for sample pre-treatment using tert-butyl methyl ether.
• Separation on a XTerra® RP18 column with a gradient elution of ammonium bicarbonate and acetonitrile.
• Quantification using UV detection at 260 nm with sorafenib as the internal standard.

Main Results:

• The developed HPLC method demonstrated linearity over a concentration range of 25-5000 ng/mL (correlation coefficients ≥ 0.99).
• High accuracy and precision were achieved, with intra-day and inter-day coefficients of variation within acceptable limits (1.17-3.15%).
• The method was successfully applied to analyze 128 letermovir levels from clinical samples.

Conclusions:

• A validated, sensitive, and robust HPLC-DAD method for letermovir quantification has been established.
• This method is suitable for routine clinical practice, enabling effective monitoring of letermovir levels in HSCT recipients.
• The assay supports optimizing letermovir prophylaxis and managing CMV infection risk in vulnerable patient populations.