Pharmacokinetics of 5-Fluorouracil Following Hepatic Intra-arterial Infusion in a VX2 Hepatic Metastasis Model

One day versus two days of hepatic arterial infusion with oxaliplatin and fluorouracil for patients with unresectable hepatocellular carcinoma

BACKGROUND

Hepatic arterial infusion chemotherapy (HAIC) with oxaliplatin and 5-fluorouracil was effective in unresectable hepatocellular carcinoma (HCC). The program of FOLFOX-HAIC in HCC was performed for 1 day (HAIC 1d) or 2 days (HAIC 2d). We hereby retrospectively compared the efficacy and safety between these two treatment regimens and explored the predictive power of thymidylate synthase (TYMS), an enzyme involved in the DNA synthesis process and metabolism of fluorouracil.

METHODS

This study included patients with a primary diagnosis of unresectable HCC. These patients received HAIC for 1 day or 2 days. The overall survival (OS), progression-free survival (PFS), tumor response, and adverse events were compared. The propensity score matching (PSM) was used to reduce bias. Peripheral blood samples before the treatments were collected and used to measure the concentration of TYMS through enzyme-linked immunosorbent assay (ELISA). ELISA was performed according to the manufacturers' guidelines.

RESULTS

We included 368 patients for this study: 248 in the HAIC 1d group and 120 in the HAIC 2d group. There was no significant difference of OS between the two groups (14.5 for HAIC 1d vs 15.3 months for HAIC 2d, p=0.46). Compared with the HAIC 1d group, the HAIC 2d group did not prolong the PFS (7.3 vs 7.5 months, p=0.91) or elevate the tumor response (42.5% vs 39.1%, p=0.53) per RECIST 1.1. In the PSM cohort, the efficacy between the two groups was similar. The total frequencies of grade 3-4 events were higher with the HAIC 2d group than with the HAIC 1d group, especially in the PSM cohort (p=0.043). Additionally, patients with TYMS low level might benefit longer OS from the HAIC 2d group (18.7 vs 13.6 months, p=0.014).

CONCLUSIONS

There was not much of a difference in efficacy between the two groups, but the HAIC for 1 day might be safer, which needed further research. The level of TYMS might be the predictive biomarkers.

Cisplatin pharmacokinetics in nontumoral pig liver treated with intravenous or transarterial hepatic chemoembolization

PURPOSE

To evaluate cisplatin (CDDP) pharmacokinetics after its intravenous (IV) or intrahepatic arterial administration (IHA) in healthy pigs with or without embolization by absorbable gelatine.

MATERIAL AND METHODS

We analysed plasmatic and hepatic drug concentration in four groups of six mini-pigs each according to the modality of administration of CDDP (1 mg/kg): IV, IHA, IHA with partial embolization using absorbable gelatine (IHA-Pe), and IHA with complete embolization (IHA-Te). Unbounded plasmatic and hepatic platinum concentrations were measured. Concentration and pharmacokinetics parameters were compared using analysis of variance.

RESULTS

For all groups, there was a rapid and biexponential decrease in free platinum concentration. Plasmatic terminal half-life (T(1/2)) was significantly decreased after embolization at 191, 178, 42, and 41 min after IV, IHA, IHA-Pe, and IHA-Te administration, respectively. Maximal plasmatic concentration and systemic exposure to CDDP (AUC(24)) values were significantly decreased after embolization (C(max) p = 0.0075; AUC(24) p = 0.0053). Hepatic CDDP concentration rapidly peaked and then decreased progressively. After 24 h, the residual concentration represented 45, 47, 60, and 63 % of C(max), respectively, after IV, IHA, IHA-Pe, and IHA-Te. Hepatic T(1/2) and AUC(∞) values were increased after embolization, but the differences were not statistically significant.

CONCLUSION

This preliminary study confirms the feasibility of a pig model to study systemic and hepatic CDDP pharmacokinetics. Systemic exposure is lower after embolization, which could minimize systemic toxicity. Hepatic T(1/2) elimination and hepatic exposition values are increased with IHA compared with IV administration.

Pharmacokinetic evaluation of pancreatic arterial infusion chemotherapy after unification of the blood supply in an animal model

PURPOSE

The purpose of this study was to investigate the potential pharmacokinetic advantage of pancreatic arterial infusion chemotherapy of 5-fluorouracil (5-FU) with temporary unification of the pancreatic blood supply for advanced pancreatic cancer in an animal model.

MATERIALS AND METHODS

Nine pigs were divided into three groups of three pigs each. 5-FU (20 mg/kg) was infused via jugular vein (group I), celiac artery (group II), and celiac artery with balloon occlusion of the superior mesenteric artery (SMA; group III). At 0, 10, 30, and 60 minutes after drug infusion, the concentrations of 5-FU were measured in plasma and tissues including the liver, pancreatic head, pancreatic uncinate process, and duodenum. Areas under the concentration-time curve (AUCs) were calculated and statistically compared.

RESULTS

The temporary unification of the pancreatic blood supply by converting from dual blood supply through the celiac artery and SMA into a single celiac arterial supply was confirmed by dye injection. Mean AUCs in the pancreas head and liver were significantly higher for groups II and III compared with group I (P < .05). In contrast, there were no significant differences in plasma 5-FU concentrations between groups. In addition, the AUC in the pancreatic uncinate process was significantly higher for group III compared with groups I and II (P < .05).

CONCLUSIONS

Pancreatic arterial infusion chemotherapy allows efficient regional drug delivery into the pancreas and liver. Importantly, the unification of the pancreatic blood supply may be required to induce maximum efficacy of arterial infusion chemotherapy for the tumor in the pancreatic uncinate process.

Transporters, enzymes, and enalapril removal in a rat (CC531-induced) liver metastatic model

Temporal changes in physiological spaces, protein expression of transporters and enzymes, and enalapril removal were appraised in the metastatic liver tumor model developed from male Wag/Rij rats after the intraportal injection of CC531 colon adenocarcinoma cells; sham-operated preparations received PBS. Liver tissue spaces, investigated with multiple indicator dilution technique in liver perfusion studies, were unchanged at week 3 after tumor induction. At week 4, however, the sinusoidal blood volume and albumin Disse space in tumor-bearing livers were slightly lower compared with those of shams. Increased levels of the canalicular ATP transporters, P-glycoprotein, multidrug resistance-associated protein 2 (Mrp2), and bile salt export pump (Bsep) at week 2 (P < 0.05), unchanged levels of Ntcp, Oatp1a1, Oatp1a4, and Mct2, but decreased levels of cytochrome P450 3a2 (Cyp3a2) and glutathione S-transferase (Gst4-4) at week 4 (P < 0.05) were observed in peritumor vs. sham-operated liver tissues with Western blotting. The steady-state extraction ratio of enalapril, a substrate that enters the liver rapidly via Oatp1a1 and primarily undergoes metabolism by the carboxylesterases, was unaffected by liver metastasis at week 4 regardless of its delivery via the portal vein or hepatic artery into the perfused liver preparations.

New intra-arterial drug delivery system for the treatment of liver cancer: preclinical assessment in a rabbit model of liver cancer

BACKGROUND

In the fight against cancer, new drug delivery systems are attractive to improve drug targeting of tumors, maximize drug potency, and minimize systemic toxicity. We studied a new drug delivery system comprising microspheres, with unique properties allowing delivery of large amounts of drugs to tumors for a prolonged time, thereby decreasing plasma levels. Liver tumors, unlike nontumorous liver, draw most of their blood supply from the hepatic artery. Exploiting this property, we delivered drug-eluting microspheres/beads (DEB) loaded with doxorubicin, intra-arterially, in an animal model of liver cancer (Vx-2).

PURPOSE

The purpose of our study was to determine the pharmacokinetics and tumor-killing efficacy of DEB.

RESULTS

Our results show that plasma concentration of doxorubicin was minimal in the animals treated with DEB at all time points (0.009-0.05 micromol/L), suggesting high tumor retention of doxorubicin. This was significantly lower (70-85% decrease in plasma concentration) than control animals treated with doxorubicin intra-arterially. Within the tumor, doxorubicin concentration peaked at 3 days (413.5 nmol/g), remaining high to 7 days (116.7 nmol/g) before declining at 14 days (41.76 nmol/g), indicating continuous doxorubicin elution from beads. In control animals, peak tumor concentration of doxorubicin was 0.09 nmol/g. Tumor necrosis (approaching 100%) was greatest at 7 days, with minimal adverse local side effects reflected in liver function tests results. The plasma concentration of doxorubicinol (doxorubicin main metabolite) was minimal.

CONCLUSIONS

Our results support the concept of DEBs as an effective way to deliver drugs to tumor. This new technology may prove to be a useful weapon against liver cancer.