Renal dysfunction in patients with radioactive iodine-refractory thyroid cancer treated with tyrosine kinase inhibitors: A retrospective study.

In 2014/2015, tyrosine kinase inhibitors (TKIs) were introduced as a secondary treatment for refractory differentiated thyroid cancer (DTC) in Japan. While renal dysfunction is an adverse event of TKI, data on this adverse event in TKI-treated DTC remains insufficient. Here, we investigated renal function in patients undergoing TKI treatment for DTC and evaluated the efficacy of dose reduction/withdrawal for cases of renal dysfunction.A total of 73 cases of radioactive iodine-refractory DTC treated with sorafenib (n = 22) or lenvatinib (n = 51) were included. Patient data evaluated were TKI treatment period, estimated glomerular filtration rate (eGFR) before and after TKI therapy, incidence and degree (maximum value at time of TKI treatment) of proteinuria, and albumin levels before and after TKI therapy were compared.The mean ΔeGFR was -6.75% with lenvatinib and +5.90% with sorafenib. It was not significant (P = .15). The mean Δalbumin was -8.90% and -5.85% with lenvatinib and sorafenib, respectively; there was no significant difference between the lenvatinib and sorafenib groups (P = .77). According to our program of TKI dose reduction and withdrawal, all patients except 2 with diabetes were successfully continuing treatment.Overall, the present results demonstrated that renal function is negatively affected by long-term TKI treatment for RAI-refractory DTC. However, heightened proteinuria, decreased eGFR and albumin levels, and significant but apparently reversible renal dysfunction were more frequent with lenvatinib than sorafenib.

Fibroblast screening for chaperone therapy in beta-galactosidosis.

We performed screening of beta-galactosidase-deficient fibroblasts for possible chemical chaperone therapy using N-octyl-4-epi-beta-valienamine (NOEV) in patients with GM1-gangliosidosis and Morquio B disease (beta-galactosidosis). Fibroblasts were cultured with NOEV for 4 days and beta-galactosidase activity was measured. Mutation analysis was performed simultaneously. Two separate criteria were set for evaluation of the chaperone effect: a relative increase of enzyme activity (more than 3-fold), and an increase up to more than 10% normal enzyme activity. Among the 50 fibroblast strains tested, more than 3-fold increase was achieved in 17 cell strains (34%), and more than 10% normal activity in 10 (20%). Both criteria were satisfied in 6 (12%), and either of them in 21 (42%). Juvenile GM1-gangliosidosis was most responsive, and then infantile GM1-gangliosidosis. This enhancement was mutation-specific. We estimate that the NOEV chaperone therapy will be effective in 20-40% of the patients, mainly in juvenile and infantile GM1-gangliosidosis patients. A molecular design may produce mutation-specific chaperone compounds for the other disease phenotypes. This cellular screening will be useful for identification of human patients with beta-galactosidase deficiency for chaperone therapy to be started in the near future.