FDA Approves Test for Everolimus Immunoassay

Nature Reviews Drug Discovery 8, 535-536 (July 2009)

The FDA has approved the first test to monitor blood levels of Everolimus in  kidney transplant patients.  This is a competitive inhibition assay using a Quantitative Microsphere System (QMS®).  An agglutination reaction between antibody and microsphere particle bound Everolimus is inhibited in the presence of free Everolimus in the patient sample.  From this a concentration-dependent classic aggultination inhibition curve can be acquired where a maximum rate of agglutination corresponds with the lowest Everolimus concentration.  When evalutated by Dasgupta et. al  the assay produced a direct linear correlation between 1.5 and 20ng/mL and a lower limit of 1.3ng/mL.  The researchers also noted a 46% cross-reactivity with sirolimus which is structurally similar to everolimus.  The QMS Everolimus Immunoassay from Thermofisher  provides a new immunoassay for the routine monitoring of Everolimus in whole blood.