Pharmacokinetics of recombinant human soluble thrombomodulin, thrombomodulin alfa in the rat

A placebo-controlled, double-blind, randomized study of recombinant thrombomodulin (ART-123) to prevent oxaliplatin-induced peripheral neuropathy

Purpose

The purpose of this clinical study was to be the first to explore whether ART-123, a recombinant human soluble thrombomodulin, prevents oxaliplatin-induced peripheral neuropathy (OIPN).

Methods

This randomized, phase IIa trial enrolled stage II/III colon cancer patients who received adjuvant mFOLFOX6 chemotherapy. Participants were randomly allocated to 3 arms in a double-blind manner: placebo (placebo: days 1–3); 1-day ART (ART-123: day 1, placebo: days 2–3); and 3-day ART (ART-123: days 1–3). ART-123 (380 U/kg/day) or placebo was infused intravenously before each 2-week cycle of mFOLFOX6. OIPN was assessed with the Functional Assessment of Cancer Therapy/Gynecological Oncology Group-Neurotoxicity-12 (FACT/GOG-Ntx-12) score by participants and the NCI Common Terminology Criteria for Adverse Events (NCI-CTCAE) by investigators.

Results

Seventy-nine participants (placebo n = 28, 1-day ART n = 27, 3-day ART n = 24) received study drugs. The least-squares mean FACT/GOG-Ntx-12 scores at cycle 12 from the mixed effect model for repeated measures were 28.9 with placebo, 36.3 with 1-day ART (vs. placebo: 7.3 [95% CI 1.9 to12.8, p = 0.009]), and 32.3 with 3-day ART (vs. placebo: 3.4 [95% CI −.1 to 9.0, p = 0.222]). The cumulative incidence of NCI-CTCAE grade ≥ 2 sensory neuropathy at cycle 12 was 64.3% with placebo, 40.7% with 1-day ART (vs. placebo: −23.5 [95% CI −48.4 to 4.0], p = 0.108), and 45.8% with 3-day ART (vs. placebo: −18.5 [95% CI −44.2 to 9.4], p = 0.264). Common adverse events were consistent with those reported with mFOLFOX6; no severe bleeding adverse events occurred.

Conclusion

ART-123 showed a potential preventive effect against OIPN with good tolerability. A larger study with 1-day ART is warranted.

NCT02792842, registration date: June 8, 2016

Electronic supplementary material

The online version of this article (10.1007/s00280-020-04135-8) contains supplementary material, which is available to authorized users.

Recombinant thrombomodulin prevented hepatic ischemia-reperfusion injury by inhibiting high-mobility group box 1 in rats

Recombinant thrombomodulin (rTM) is a novel anticoagulant and anti-inflammatory agent that inhibits secretion of high-mobility group box 1 (HMGB1) from liver. We evaluated the protective effects of rTM on hepatic ischemia-reperfusion injury in rats. Ischemia was induced by clamping the portal vein and hepatic artery of left lateral and median lobes of the liver. At 30 min before ischemia and at 6 h after reperfusion, 0.3 ml of saline (IR group) or 0.3 ml of saline containing 6 mg/kg body weight of rTM (IR-rTM group) was injected into the liver through inferior vena cava or caudate vein. Blood flow was restored at 60 min of ischemia. Blood was collected 30 min prior to induction of ischemia and before restoration of blood flow, and at 6, 12, and 24 h after reperfusion. All the animals were euthanized at 24 h after reperfusion and the livers were harvested and subjected to biochemical and pathological evaluations. Serum levels of ALT, AST, and HMGB1 were significantly lower after reperfusion in the IR-rTM group compared to IR group. Marked hepatic necrosis was present in the IR group, while necrosis was almost absent in IR-rTM group. Treatment with rTM significantly reduced the expression of TNF-α and formation of 4-hydroxynonenal in the IR-rTM group compared to IR group. The results of the present study indicate that rTM could be used as a potent therapeutic agent to prevent IR-induced hepatic injury and the related adverse events.

Population pharmacokinetics of thrombomodulin alfa in pediatric patients with hematological malignancy and disseminated intravascular coagulation

BACKGROUND

Thrombomodulin alfa (TM-α) is a new class of anticoagulant drug for patients with disseminated intravascular coagulation (DIC). This study aimed to determine the pharmacokinetics of TM-α and determine the optimal dose in pediatric patients with hematological malignancy and DIC.

PROCEDURE

Pediatric patients with hematological malignancy and DIC were administered TM-α at a dose of 0.06 mg/kg (380 U/kg) over 30 min every 24 hr. Blood samples were taken at steady state before the start, immediately after the end, and 24 hr after the start of the sixth administration. Population pharmacokinetic analysis was performed using sparse samples with the nonlinear mixed-effect modeling program NONMEM^® , version 7.3.

RESULTS

The actual and predicted plasma concentrations of TM-α based on the final population pharmacokinetic model showed a good linear correlation. Clearance and volume of distribution of TM-α were affected by body weight. The clearance of TM-α in pediatric patients with hematological malignancy and DIC was higher than that in adults as previously reported. Six of eight patients did not achieve the target trough concentration at steady state. Furthermore, the pharmacokinetic simulation based on the estimated pharmacokinetic parameters from the final model demonstrated that TM-α administered at a dose of 0.06 mg/kg every 24 hr also failed to achieve the target trough concentration at steady state in the majority of pediatric patients.

CONCLUSIONS

Our study shows that further dose adjustment of TM-α is necessary considering the higher clearance per body weight in pediatric patients with hematological malignancy and DIC.

Pharmacokinetics of recombinant human soluble thrombomodulin in disseminated intravascular coagulation patients with acute renal dysfunction

Recombinant human soluble thrombomodulin (ART-123) is a novel anticoagulant for patients with disseminated intravascular coagulation (DIC). It is widely used in clinical settings throughout Japan. Furthermore, a global Phase 3 study is currently being conducted. In healthy subjects, ART-123 is excreted mainly via the kidneys. Therefore, ART-123 dose decrease was recommended in DIC patients with severe renal dysfunction. However, the pharmacokinetics of ART-123 in DIC patients with severe acute renal dysfunction has not been elucidated. In an open-label, multicentre, prospective, clinical pharmacological study, we investigated the pharmacokinetics and safety of ART-123 upon repeated administration to DIC patients. ART-123 was administered to patients at a dose of 130 or 380 U/kg/day for six consecutive days. Plasma concentrations of ART-123 were measured at 21 time points until eight days after the final administration. Urinary excretion rates during the first 24 hours (h) were calculated. Patient renal functions were evaluated by measuring 24-h creatinine clearance (Ccr). Forty-three patients were enrolled in the present study. The urinary excretion rates of ART-123 correlated closely with 24-h Ccr. Total body clearance of ART-123 was also weakly related with 24-h Ccr. However, the plasma concentrations of ART-123 were not considerably different among patients with different renal function. Two patients had subcutaneous haemorrhage as an adverse event related to ART-123. In conclusion, plasma concentrations of ART-123 may not be different among patients with different renal functions. ART-123 was well tolerated in these patients.

Population pharmacokinetic analysis of thrombomodulin alfa to support dosing rationale in patients with renal impairment

Thrombomodulin alfa is a soluble recombinant human thrombomodulin that was reported to enhance the reversal of disseminated intravascular coagulation (DIC) in subjects with sepsis or hematologic malignancy and reduce mortality in subjects with sepsis and DIC. Population pharmacokinetic (PK) analysis of thrombomodulin alfa was performed based on rich samples collected in 24 healthy subjects (0.02 and 0.06 mg/kg) and sparse samples collected in 368 subjects with sepsis and DIC (0.06 mg/kg). Sources of variability (baseline characteristics, markers of renal/liver function, hematocrit, and disease severity) were explored using non-linear mixed effect modeling to support dosing rationale in patients with sepsis and DIC. Plasma concentrations of thrombomodulin alfa were best fitted with a one-compartment model. Body weight and creatinine clearance were important covariates describing the PK of thrombomodulin alfa. Typical CL values in patients with normal renal function, or mild, moderate and severe renal impairment were 0.158, 0.145, 0.128, and 0.105 L/h, respectively. Based on simulations, a 0.06 mg/kg dosing of thrombomodulin alfa is expected to result in drug exposure within the therapeutic range of the product (300-5,400 ng/mL), with minimum risks of bleeding in patient with normal and impaired renal functions.

Pharmacokinetics and pharmacodynamics of recombinant soluble thrombomodulin in disseminated intravascular coagulation patients with renal impairment

Recombinant human soluble thrombomodulin (TM-α) was recently developed as an anticoagulant for patients with disseminated intravascular coagulation (DIC). However, the pharmacokinetics and pharmacodynamics of TM-α in DIC patients with severe renal impairment have not yet been elucidated. We investigated the pharmacokinetics and pharmacodynamics of TM-α in DIC patients with severe renal impairment. Eleven DIC patients with severe renal impairment (creatinine clearance <30 mL/min) and 10 DIC patients without severe renal impairment (creatinine clearance ≥30 mL/min) were included in this study. In all patients, a dose of 380 U/kg of TM-α was administered during a 30-min infusion. Blood samples were taken before the start of the first TM-α administration, and at 0.5, 2, 4, 8, and 24 h after the start of administration. Although the clearance of TM-α in the patients with renal impairment was 80% of that in the patients without renal impairment, none of the pharmacokinetic values were significantly different between the groups. In the pharmacokinetic simulation, however, the trough levels of TM-α increased gradually in the patients with renal impairment when the same dose of TM-α was repeatedly administered. After the administration of TM-α, the prothrombinase activities in the patients in both groups were sufficiently inhibited during the observation period. Although the pharmacokinetic values in DIC patients with severe renal impairment were only slightly different from those in DIC patients without severe renal impairment, we need to pay attention to the elevation of the trough levels of TM-α when the same dose of TM-α is repeatedly administered.

Model-based analysis of covariate effects on population pharmacokinetics of thrombomodulin alfa in patients with disseminated intravascular coagulation and normal subjects

Thrombomodulin alfa is the recombinant extracellular domain of human thrombomodulin, which shows anticoagulation activity. To elucidate the pharmacokinetics of thrombomodulin alfa in patients with disseminated intravascular coagulation (DIC), population pharmacokinetic (PPK) analysis was performed using plasma concentration data obtained in phase 1 (20 patients, 348 time points) and phase 2 (116 patients, 305 time points) clinical trials. The actual and predicted plasma concentrations of thrombomodulin alfa based on the final PPK model showed a good linear correlation (R = 0.9504), and the pharmacokinetics of thrombomodulin alfa in DIC patients were affected by body weight, age, renal dysfunction, and hematocrit value. The distribution volume and clearance (CL) were proportional to body weight and were significantly increased in patients with lower hematocrit value (male <40%, female <35%). Furthermore, CL was decreased in patients with renal dysfunction and in elderly patients. Based on these results, the standard dose of thrombomodulin alfa is adjusted according to body weight. However, further dose adjustment is not needed based on age and hematocrit value, since these factors did not cause the large changes in plasma concentration that can affect the efficacy or safety.