Pharmacokinetics of edoxaban in EGFR-mutated non-small cell lung cancer patients with venous thromboembolism

BACKGROUND

The risk of venous thromboembolism (VTE) is increased 7-fold in patients with cancer than in those without. Low-molecular-weight heparin is the standard treatment for cancer-associated VTE. Direct oral anticoagulants (DOACs) are not inferior to low-molecular-weight heparin with respect to the general outcome of recurrent VTE. Warfarin is associated with a risk of bleeding when used in combination with gefitinib or erlotinib which are epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). It is unclear, however, whether combination treatments with EGFR-TKIs and DOACs pose the same risk. We aimed to identify anticancer drugs and anticoagulants that can be used safely in combination, as accompanying research to an observational study on VTE incidence rates in lung cancer patients (Rising-VTE/NEJ037 study).

METHODS

Twelve patients receiving EFGR-TKI monotherapy and VTE treatment were enrolled. Blood samples were collected in time series after the first dose of edoxaban, and further samples were collected within 8-15 days after administering EGFR-TKIs. The pharmacokinetics (PK) of edoxaban were analyzed using a non-compartmental model.

RESULTS

Edoxaban concentrations (30 mg once daily) were measured in eight patients. PK analyses showed no significant differences before and after co-administration of EGFR-TKIs (gefitinib, erlotinib, and afatinib).

CONCLUSIONS

Our findings indicate that the PK of edoxaban was not considerably affected by co-administration of EGFR-TKIs (gefitinib, erlotinib, and afatinib).

A thiol-mediated active membrane transport of selenium by erythroid anion exchanger 1 protein

In this paper, we describe a thiol-mediated and energy-dependent membrane transport of selenium by erythroid anion exchanger 1 (AE1, also known as band 3 protein). The AE1 is the most abundant integral protein of red cell membranes and plays a critical role in the carbon dioxide transport system in which carbon dioxide is carried as bicarbonate in the plasma. This protein mediates the membrane transport of selenium, an essential antioxidant micronutrient, from red cells to the plasma in a manner that is distinct from the already known anion exchange mechanism. In this pathway, selenium bound to the cysteine 93 of the hemoglobin β chain (Hb-Cysβ93) is transported by the relay mechanism to the Cys317 of the amino-terminal cytoplasmic domain of the AE1 on the basis of the intrinsic interaction between the two proteins and is subsequently exported to the plasma via the Cys843 of the membrane-spanning domain. The selenium export did not occur in plain isotonic buffer solutions and required thiols, such as albumin, in the outer medium. Such a membrane transport mechanism would also participate in the export pathways of the nitric oxide vasodilator activity and other thiol-reactive substances bound to the Hb-Cysβ93 from red cells to the plasma and/or peripherals.

[Histopathological study of rabbit anterior capsule opacification after IOL surgery]

We investigated the histopathology of anterior capsular opacification after intraocular lens (IOL) implantation in a rabbit eye. Sixteen eyes of eight albino rabbits underwent continuous circular capsulorhexis, phacoemulsification, and in-the-bag IOL implantation. The anterior capsules were examined by slitlamp, light microscopy, and transmission electron microscopy. Anterior capsular opacification during the fourth week after surgery appeared similar to that of the human eye. Multi-layered lens epithelial cells and collagenous fibers were recognized in the anterior capsular opacification. New lens fibers, however, extended between the anterior capsules and the IOLs, and caused the opacification to become obscure. This model may be useful for investigating anterior capsular opacification after cataract surgery during the early postoperative period.