Rational application of gefitinib in NSCLC patients with sensitive EGFR mutations based on pharmacokinetics and metabolomics.

Gefitinib has been available in the market for 20 years, but its pharmacokinetic mechanism of response is little known. In this study, we examined the pharmacokinetic and metabolomic profiles in non-small cell lung cancer (NSCLC) patients with sensitive EGFR mutations. A total of 216 advanced NSCLC patients were enrolled, and administered gefitinib at the standard dosage of 250 mg/day, which was established in heterogeneous subjects with non-sensitive mutations. We identified and quantified three main metabolites (named as M1, M2 and M3) in the plasma of patients, the correlations between the concentration of gefitinib/metabolites and efficacy were analyzed. In exploratory and validation set, gefitinib concentration was not correlated with clinical effects. Considering the result that the therapeutic effects of 250 mg/2-day was better than that of 250 mg/day in a multiple center clinical trial, the standard dose might be higher than that for maximal efficacy according to the hypothetical dose-response curve. Among the three metabolites, the IC50 of M2 in HCC827 and PC9 cell lines was significantly lower, and Conc.brain/Conc.plasma of M2 in mice was significantly higher than those of gefitinib, suggesting its higher potential to penetrate blood-brain barrier and might be more effective in the treatment of brain metastatic tumor than gefitinib. Consistently and attractively, higher M2 plasma concentration was found to be correlated with better clinical outcome in patients with brain metastases (the median PFS of CM2 < 12 ng/mL and CM2 ≥ 12 ng/mL were 17.0 and 27.1 months, respectively, P = 0.038). The plasma concentration of M2 ≥ 12 ng/mL was a strong predictor of the PFS of NSCLC patients. In conclusion, for NSCLC patients with EGFR sensitive mutations, the standard dose is suspectable and could be decreased reasonably. M2 plays an important role in efficacy and may be more effective in the treatment of metastatic tumor than gefitinib.

Intravenous transplantation of allogeneic bone marrow mesenchymal stem cells and its directional migration to the necrotic femoral head.

In this study, we investigated the feasibility and safety of intravenous transplantation of allogeneic bone marrow mesenchymal stem cells (MSCs) for femoral head repair, and observed the migration and distribution of MSCs in hosts. MSCs were labeled with green fluorescent protein (GFP) in vitro and injected into nude mice via vena caudalis, and the distribution of MSCs was dynamically monitored at 0, 6, 24, 48, 72 and 96 h after transplantation. Two weeks after the establishment of a rabbit model of femoral head necrosis, GFP labeled MSCs were injected into these rabbits via ear vein, immunological rejection and graft versus host disease were observed and necrotic and normal femoral heads, bone marrows, lungs, and livers were harvested at 2, 4 and 6 w after transplantation. The sections of these tissues were observed under fluorescent microscope. More than 70 % MSCs were successfully labeled with GFP at 72 h after labeling. MSCs were uniformly distributed in multiple organs and tissues including brain, lungs, heart, kidneys, intestine and bilateral hip joints of nude mice. In rabbits, at 6 w after intravenous transplantation, GFP labeled MSCs were noted in the lungs, liver, bone marrow and normal and necrotic femoral heads of rabbits, and the number of MSCs in bone marrow was higher than that in the, femoral head, liver and lungs. Furthermore, the number of MSCs peaked at 6 w after transplantation. Moreover, no immunological rejection and graft versus host disease were found after transplantation in rabbits. Our results revealed intravenously implanted MSCs could migrate into the femoral head of hosts, and especially migrate directionally and survive in the necrotic femoral heads. Thus, it is feasible and safe to treat femoral head necrosis by intravenous transplantation of allogeneic MSCs.