Affinity Capture Elution (ACE) ELISA Method Development and Validation for Novel RPH-104 Drug Immunogenicity Evaluation.

As the number of therapeutic protein products is growing rapidly, there is a strong need for the development of bioanalytical methods that are easy to perform, specific, sensitive, robust, and affordable. Methods for immunogenicity evaluation of therapeutic proteins take an important place in this field of bioanalytics. The aim of the study was to develop a method for immunogenicity testing of the novel RPH-104 drug using the Affinity Capture Elution (ACE) ELISA technique. RPH-104 is a promising Interleukin-1 (IL-1) inhibitor that is currently undergoing a series of clinical studies, including those on socially significant and orphan diseases. The developed method was validated for assay cut-point, sensitivity, selectivity, drug tolerance, hook effect, specificity, precision, and stability. Method sensitivity was established at 114.9 ng/mL, while low and high positive controls were equal to anti-RPH-104 antibody concentrations of 155 ng/mL and 2500 ng/mL, respectively. Method specificity was confirmed in the presence of the interfering compounds, namely IL-1α, IL-1ß, and IL1-Ra. The developed and validated ELISA method was successfully applied to subject samples.

Breastfeeding in Patients with Chronic Myeloid Leukaemia: Case Series with Measurements of Drug Concentrations in Maternal Milk and Literature Review.

Breastfeeding in patients with chronic myeloid leukaemia (CML) during tyrosine kinase inhibitors (TKIs) therapy is not recommended but interruption of TKI treatment may cause the loss of remission. We studied the 3 cases of pregnancy and breastfeeding in women with CML and observed that stopping treatment without major molecular response may end in haematological relapse. The concentrations of nilotinib and imatinib in maternal milk were measured and nilotinib distribution in human breast milk was demonstrated for the first time. The estimated maximal doses of imatinib and nilotinib which an infant may ingest with the maternal milk were less than the therapeutical doses. However, the unknown impact of the low dose chronic exposure to these TKIs in infants imposes the limitations on their use during breastfeeding. Breastfeeding without TKI treatment may be safe with molecular monitoring, but preferably in those patients with CML who have durable deep molecular response.

Placental transfer of tyrosine kinase inhibitors used for chronic myeloid leukemia treatment.

Both favorable pregnancy outcomes and fetal abnormalities have been associated with the use of tyrosine kinase inhibitors (TKIs) during pregnancy. The placental transfer of TKIs in humans is poorly understood. We observed women with chronic myeloid leukemia who used imatinib or nilotinib during the late pregnancy stages. The newborns had no birth abnormalities. We evaluated the drug concentrations in maternal blood, umbilical cord blood, and placental samples collected during labor. We found limited placental transfer of the TKIs. The fetal/maternal concentration ratio ranged from 0.5 to 0.58 for nilotinib and from 0.05 to 0.22 for imatinib. The placental/maternal ratio was higher for imatinib than for nilotinib. Theoretical pharmacokinetic modeling of passive placental crossing was insufficient to predict the in vivo data because the calculated fetal/maternal ratio was close to 1 for both drugs. We propose that active placental transport contributes to fetal protection against TKI exposure during pregnancy.