A placebo-controlled, double-blind study of mesoglycan in the treatment of chronic venous ulcers.

OBJECTIVES: to assess the effect of treatment with mesoglycan, a sulphated polysaccharide compound, on the healing of venous ulcers. Design randomised, placebo-controlled, double-blind, multicentre trial. METHODS: non-diabetic outpatients with chronic venous insufficiency confirmed by duplex ultrasound, normal ankle/arm pressure index and presence of a leg ulcer were eligible. Patients were randomised to mesoglycan, 30 mg/day intramuscularly for 3 weeks followed by 100 mg/day orally, or matching placebo, as an adjunct to compression therapy and topical wound care. Treatment and observation were continued until complete ulcer healing or for 24+/-1 weeks. Time to ulcer healing and healing rates were estimated with the Kaplan-Meier method. RESULTS: One hundred and eighty-three patients were randomised and included in the analysis (92 mesoglycan, 91 placebo). Median ulcer area upon inclusion was 3.6 cm(2)in the mesoglycan group and 3.9 cm(2)in the placebo group. The estimated time to heal 75% of the patients was 90 days on mesoglycan versus 136 days on placebo, while the cumulative rate of healing by the end of observation was 97% versus 82%, respectively. The difference in favour of mesoglycan was statistically significant (p < 0.05, centre-stratified Cox's model). The relative risk of ulcer healing with mesoglycan was 1.48. The rate of adverse events was 7/92 on mesoglycan and 6/91 on placebo. CONCLUSIONS: treatment with mesoglycan in addition to established venous ulcer therapy resulted in a significantly faster and more frequent ulcer healing, and did not raise any safety concerns.

Treatment of intermittent claudication with mesoglycan--a placebo-controlled, double-blind study.

OBJECTIVE: To assess the effect of treatment with mesoglycan, a sulphated polysaccharide compound, on the walking capacity of patients with stage II peripheral arterial disease. METHODS: Non-diabetic outpatients with intermittent claudication, duplex ultrasound evidence of peripheral atherosclerosis, ankle/arm index <0.80, systolic ankle pressure >50 mmHg, and absolute walking distance (AWD) between 100 and 300 m (standardised treadmill test) were eligible. After a 5-week run-in on single-blind placebo, patients were randomised to double-blind treatment with mesoglycan, 30 mg/day intramuscularly for 3 weeks followed by 100 mg/day orally for 20 weeks, or matching placebo. All patients received low-dose aspirin and lifestyle instructions. Clinical response was defined as an AWD increase at Week 23 >50% over baseline. Health-related quality of life and ischaemic events were assessed as secondary efficacy variables. RESULTS: 242 patients were randomised and 237 were assessed for clinical response. Patients achieving clinical response were 59/118 with mesoglycan (50.0%) and 31/119 with placebo (26.1%; p <0.001). Geometric mean AWD increased from 192 to 298 m with mesoglycan, and from 192 to 238 m with placebo (p <0.001). Pain-free walking distance showed a non-significant increase with mesoglycan (p = 0.057). Changes in quality of life scores were in favour of mesoglycan. The rate of ischaemic events was 1/120 on mesoglycan and 6/122 on placebo (p = 0.053). The rate of non-ischaemic adverse events leading to treatment discontinuation was 7/120 and 4/122, respectively. CONCLUSION: Treatment with mesoglycan improves the walking capacity of patients with intermittent claudication, and might confer additional antithrombotic protection over that of aspirin.

Dermatan sulphate for the prevention of postoperative venous thromboembolism in patients with cancer. DOS (Dermatan sulphate in Oncologic Surgery) Study Group.

BACKGROUND: Patients undergoing surgery for cancer are at high risk for venous thromboembolism (VTE). Agents that selectively inhibit thrombin, such as dermatan sulphate, have potential for a favourable benefit-risk ratio in the prevention of this complication. METHODS: Patients scheduled for elective abdominal, thoracic, gynecologic or urologic surgery for cancer resection, were randomised to dermatan sulphate (600 mg intramuscularly on the second day before surgery, then 300 mg once daily), or calcium heparin (5,000 IU subcutaneously t.i.d., starting 2 hours before operation). Both treatments were continued until postoperative day 7 or until adequate mobilisation was achieved. Bilateral venography was scheduled at the end of treatment. Venograms were centrally assessed in blind conditions. The study outcomes were VTE (venographically proven deep vein thrombosis IDVT] or symptomatic, objectively confirmed pulmonary embolism) and bleeding complications. RESULTS: At 27 centres, 842 patients were randomised and underwent surgery (418 dermatan sulphate, 424 heparin). Efficacy was assessed in 521 patients with adequate venography and/or confirmed pulmonary embolism. DVT was observed in a total of 96 patients; symptomatic non-fatal pulmonary embolism developed in 2 patients (one per group), who also had DVT at venography. Postoperative VTE occurred in 40 of 267 patients on dermatan sulphate, 15.0%, versus 56 of 254 patients on heparin. 22.0% (p = 0.033). Relative risk reduction was 32.7% (95% confidence interval, 3.1 to 53.2%). The rate of bleeding complications in all operated patients was 6.9% with dermatan sulphate and 7.5% with heparin (confidence interval for the absolute risk difference, -4.1 to 2.9%). The inhospital mortality rate was 1.2% and 1.4%, respectively. CONCLUSIONS: In oncologic surgery, dermatan sulphate prevents VTE more effectively than heparin without increasing bleeding complications.

Dermatan sulphate in patients with heparin-induced thrombocytopenia.

Patients with thromboembolic diseases who develop heparin-induced thrombocytopenia (HIT) type II require an alternative anticoagulation strategy. Dermatan sulphate (DS) was administered to five patients with thromboembolic diseases who developed HIT type II and showed an in vitro cross-reactivity with low molecular weight heparins. The platelet count and the extension of thrombosis were monitored during DS administration. In four of the five patients the platelet count rapidly increased after heparin was discontinued and DS started. A low platelet count persisted in the single patient with cross-reactivity to DS, up to 4 d after its discontinuation. None of the patients experienced thrombus extension, haemorrhagic side-effects or other adverse events.

Individualized anticoagulation with dermatan sulphate for haemodialysis in chronic renal failure.

BACKGROUND: Dermatan sulphate (DS) is a selective thrombin inhibitor with antithrombotic properties and low bleeding potential. In preliminary studies it was reported to be effective for preventing clot formation in the haemodialysis circuit. METHODS: Ten patients on maintenance haemodialysis for chronic renal failure underwent three consecutive investigation phases. In phase 1 (individual dose titration), repeated dialyses were performed with increasing doses of DS until successful dialysis was obtained in two sessions at the same dose. In phase 2, individualized DS doses were validated by a randomized crossover comparison with the individual heparin dose of each patient. In phase 3, each patient underwent 24 consecutive dialyses with DS over 8 weeks. Successful dialysis was defined as completion of the procedure without visible clot formation in the bubble traps and lines or a greater than 20% decrease in dialyser capacity. Dialysis efficiency (decrease in serum urea and creatinine, Kt/V), APTT prolongation, bleeding time, and DS plasma concentrations were also assessed. RESULTS: Phase 1: successful dialysis was achieved in nine patients with 4 mg/kg DS as a predialysis intravenous bolus followed by continuous infusion of 0.65 mg/kg/h. One patient required 5 mg/kg plus 1.3 mg/kg/h. Phase 2: no statistically significant differences were found between DS and heparin in any of the investigated variables. Residual dialyser capacity and dialysis efficiency indexes indicated equivalent efficacy. Phase 3: residual dialyser capacity and dialysis efficiency did not change with time. There was no accumulation of DS in plasma. No bleeding or thrombocytopenia were observed. CONCLUSIONS: The dose of DS can be individually titrated to suppress clot formation during haemodialysis as efficiently as with individualized heparin. Such an individualized DS regimen maintains its anticoagulant efficacy and is safe in prolonged use.

Effect of dermatan sulphate on activated partial thromboplastin time determined with different reagents.

Five widely used activated partial thromboplastin time (APTT) reagents (Actin-FS, Actin-FSL, Hemolab Silimat, IL-Test APTT Ellagic Acid and Thrombofax Activated) were compared for their sensitivity and precision in measuring the effect of dermatan sulphate on blood coagulation. On each of 4 days, aliquots of the same normal human plasma pool were mixed with dermatan sulphate (MF701) at concentrations ranging from 10 to 100 micrograms/ml, and APTT was measured in duplicate with all reagents by a photo-optical coagulometer. The order of testing between and within reagents was changed every day. The relationship of APTT ratio to dermatan sulphate concentration was linear with all the reagents. There were statistically significant differences between reagents in their sensitivity to DS, as reflected by linear regression slopes. IL-Test was the most sensitive reagent. At dermatan sulphate concentrations of 20, 50, and 80 micrograms/ml APTT ratio ranged from 1.5 to 1.7, 1.9 to 2.3 and 2.3 to 2.9, respectively, according to the reagent. The lambda coefficient and coefficient of variation derived from regression analysis, both reflecting assay precision, ranged from 0.57 to 0.71 and from 4.6 to 5.1%, respectively, with all but the least precise reagent. The best sensitivity/precision balance was displayed by IL-Test. The APTT reagent should therefore be standardized, with special regard to sensitivity to DS, when testing the relationship of dermatan sulphate clinical effects to APTT response.

Intramuscular dermatan sulfate MF701 in patients with hip fracture: relationship between pharmacokinetics and antithrombotic efficacy.

Two groups of 23 and 84 patients with hip fracture received intramuscularly 100 and 300 mg dermatan sulfate (MF701) b.i.d., respectively, for the prophylaxis of deep vein thrombosis. Median duration of treatment was 17 and 16 days, respectively. Four blood samples were collected from each patient while under treatment. Plasma levels of dermatan sulfate were determined by a chromogenic substrate assay. A one-compartment model for multiple doses was employed to estimate the pharmacokinetic parameters. Fitting was applied to mean plasma concentrations calculated for each sampling time and weighted according to the number of samples available at each time. Thrombin clotting time was measured on the same plasma samples. Antithrombotic efficacy was assessed by bilateral venography. Plasma levels of dermatan sulfate increased gradually throughout the treatment, indicating a marked accumulation process. Time to reach steady-state was 14 or 9 days with 100 or 300 mg b.i.d., respectively. This was due to an apparent prolonged terminal half-life (68 or 43 h), which actually reflected slow absorption from the injection sites. The clinical efficacy of MF701 in preventing DVT was found to be dependent on the plasma concentration of the drug and also, but less significantly, on the prolongation of thrombin clotting time. Dermatan sulfate plasma levels greater than 9 micrograms/ml are advisable to optimize efficacy in hip fracture patients.

Dermatan sulphate for the treatment of disseminated intravascular coagulation (DIC) in acute leukemia: a randomised, heparin-controlled pilot study.

Efficacy and safety of i.v. dermatan sulphate (DS) and heparin (H) in controlling laboratory alterations due to DIC were compared in 10 patients with acute leukaemia, in a prospective, randomised pilot study. The time courses of the coagulation and fibrinolysis markers for DIC were similar in the two treatment groups except for activated partial thromboplastin time and thrombin time, which were prolonged in the H but not in the DS group. Blood product support tended to be greater in the H than in the DS group. DS appears to be as effective as H in controlling thrombin production during leukaemic cytolysis and may represent a safer alternative to H in the management of DIC in acute leukaemia.

Is heparin the ideal anticoagulant for cardiopulmonary bypass? Dermatan sulphate may be an alternate choice.

Performance of cardiopulmonary bypass (CPB) during cardiac surgery requires the administration of high dose heparin to prevent CPB pump occlusion. However, this heparin use is associated with bleeding side-effects. Moreover, at the end of CPB, the heparin must be neutralized with protamine sulphate, which is also associated with adverse side-effects. A number of recent studies suggest that dermatan sulphate may be useful as an alternate anticoagulant to heparin. We determined whether CPB could be performed using dermatan sulphate instead of heparin, in an adult pig CPB model. When heparin was used, a high dose (> 200 U/kg, which generated > 3 anti-thrombin U/ml of plasma), was required to perform successful CPB and to maintain CPB pump patency. This dose was associated with a post CPB bleeding of approximately 600 ml/2 h. In contrast, successful CPB could be achieved when the pigs were given lower doses of dermatan sulphate than heparin, which in turn, were associated with less bleeding. We conclude that dermatan sulphate may be an alternate anticoagulant for cardiac surgery.

The pharmacokinetics and pharmacodynamics of dermatan sulphate MF701 during haemodialysis for chronic renal failure.

Single i.v. bolus doses of dermatan sulphate MF701 were administered before the onset of haemodialysis to patients with chronic renal failure, to prevent clotting in the extracorporeal circuit. Six patients received 2 mg kg-1; six were given 2.5 and 3 mg kg-1; 13 received 4.5 and 6 mg kg-1. Plasma MF701 concentrations (chromogenic assay), activated partial thromboplastin time (APTT) and plasma markers of coagulation and platelet activation (TAT and beta-TG) were measured over 4 or 8 h from the onset of dialysis. The disposition of MF701 was described by a monoexponential function. C(0) and AUC values increased proportionally with dose. Volumes of distribution (approximately 4 l) were dose-independent. Half-lives showed a non significant increase with dose (from 2.2 to 3.1 h) and were 2.5-3 times longer than those reported for healthy subjects. There was a significant correlation between plasma MF701 concentration and its effects in prolonging APTT and suppressing TAT and beta-TG generation during dialysis.

Dermatan sulphate: a safe approach to prevention of postoperative deep vein thrombosis.

To assess the efficacy and safety of dermatan sulphate (MF 701) in preventing postoperative deep vein thrombosis (DVT), 324 patients aged 40 years or over undergoing elective major general surgical operations were included in a randomized trial comparing MF 701 (100 mg intramuscularly once a day) with unfractionated calcium heparin (UFH, 5000 units subcutaneously three times daily). Both treatments were initiated before operation and continued until discharge. In all, 316 patients were included in the analysis (MF 701, 157; UFH, 159). Serial impedance plethysmography was performed in all patients; a 125I-radiolabelled fibrinogen uptake test was added to impedance plethysmography in a randomized subsample of 62 patients (MF 701, 28; UFH, 34). Positivity in either test was confirmed where possible by venography. DVT was diagnosed by venography or, when this could not be performed, by positivity of either impedance plethysmography or fibrinogen uptake test. The incidence of DVT was 3.1 per cent (patients receiving MF 701) and 1.6 per cent (those receiving UFH) in patients undergoing impedance plethysmography alone, and 7.1 and 11.8 per cent, respectively, in those undergoing both impedance plethysmography and fibrinogen uptake test; in neither case was the difference between treatments statistically significant. There were five in-hospital deaths, two in patients receiving MF 701 and three in patients on UFH. The incidence of clinically overt haemorrhage was 5.7 per cent in patients on MF 701 and 17.6 per cent in those on UFH (P less than 0.01). Postoperative transfusions and reoperations due to bleeding were significantly less frequent in patients receiving MF 701. Mortality rates at 3 months were similar for the two treatment groups. Compared with standard prophylaxis using UFH, MF 701 showed a similar efficacy with a significantly greater safety.

A randomised, double-blind, placebo-controlled trial of dermatan sulphate for prevention of deep vein thrombosis in hip fracture.

Dermatan sulphate (MF 701) is a natural glycosaminoglycan that catalyses thrombin inhibition by heparin cofactor II. The aim of the study was to evaluate the efficacy and safety of MF 701 for prevention of deep vein thrombosis (DVT) in patients with hip fracture. A randomised, double-blind, placebo-controlled design was used to assess two dose regimens of MF 701 in two consecutive study phases. Treatment was started within 48 h from the trauma and continued for 14 days for non-operated patients or until the 10th postoperative day. Bilateral mandatory venography was used to assess the end-point. Eighty patients were included in the first phase (40 MF 701, 40 placebo). MF 701, 100 mg IM b.i.d., did not reduce incidence of DVT from that on placebo and did not induce any bleeding. In the second phase 126 patients were included, with a randomisation ratio of 2:1 (84 MF 701, 300 mg IM b.i.d., 42 placebo). Bilateral venography was obtained for 110 patients. The incidence of DVT was 64% (23/36) in the placebo group and 38% (28/74) in the MF 701 group (p = 0.01; odds ratio [OR] = 0.34, 95% confidence limits [CL] = 0.15-0.80p; proximal DVTs were 42% (15/36) and 20% (15/74), respectively (p = 0.02; OR = 0.36, CL = 0.15-0.89). No significant differences were found in haemorrhagic complications (2.4% in each group), blood loss from drains, blood transfusions, haemoglobin and haematocrit values. This study is the first demonstration that dermatan sulphate is a clinically effective antithrombotic agent without bleeding effects. It also provides evidence of the biological role of heparin cofactor II.

The pharmacokinetics of dermatan sulphate MF701 in healthy human volunteers.

1. The pharmacokinetics of dermatan sulphate MF701 were studied in 12 healthy males after administration of single intravenous bolus (200 mg), intramuscular (100 and 300 mg) and oral (1 g) doses. The study was conducted according to a within-subject crossover design in two paired blocks. 2. Plasma drug concentrations were measured using a competitive binding assay and a range of biological activity assays, including a sensitive catalysed thrombin inhibition test. 3. Following intravenous administration, plasma concentrations of dermatan sulphate determined by competitive binding assay were described by a two-compartment open model with an initial t1/2, in of 0.6 h and a t1/2,z of 7.5 h. Biological activity assays were insufficiently sensitive to detect the second phase, and therefore yielded apparent monoexponential kinetics. 4. After intramuscular injection the apparent bioavailability of dermatan sulphate was 16-20%. Plasma drug concentrations increased in proportion to dose when measured by competitive binding assay. Low concentrations persisted for more than 24 h at the higher dose, and these may prove therapeutically relevant on chronic administration. 5. We confirm that dermatan sulphate is the only glycosaminoglycan known to generate significant plasma concentrations following oral administration. Oral bioavailability was estimated to be 7%.

Effects of subcutaneously administered dermatan sulfate (MF 701) on the coagulation and fibrinolytic parameters of healthy volunteers.

Eight healthy volunteers were given single subcutaneous doses of dermatan sulfate (DS, 100, 200 and 400 mg), heparin (5,000 IU) and placebo in random order. Wash-out between treatments was greater than or equal to 10 days. Serial blood samples were taken before and up to 24 hours after treatment to measure coagulation and fibrinolytic parameters. Thrombin generation was significantly inhibited by DS and heparin as compared to placebo. The effect of DS was dose-dependent. Peak inhibition after 200 mg DS was comparable to that of 5,000 IU heparin, but lasted longer. A small, bordeline significant prolongation of APTT was observed after 400 mg DS and heparin. The changes in PAI and fibrinolytic activities were those of the circadian variation. No changes were seen in the other parameters tested. In conclusion, single s.c. doses of DS (200, or 400 mg) inhibit ex vivo thrombin generation equally or more than 5,000 IU heparin and for a longer time. The effect of both treatments on fibrinolysis is negligible.

Human pharmacokinetics and pharmacodynamics of MF 701 dermatan sulfate administered by continuous intravenous infusion.

The pharmacokinetics and haemostatic effects of MF 701 dermatan sulfate (DS) administered by i.v. infusion were studied in 11 healthy volunteers. Each subject received 0.6 mg kg-1 h-1 MF 701 for 10 h. DS plasma concentrations were measured by a chromogenic assay based on the catalysis of thrombin inhibition by HCII. DS plasma levels followed a single compartment pharmacokinetic model, with a half-life of 1.28 +/- 0.46 h, a plasma clearance of 2.75 +/- 0.46 l/h and a volume of distribution of 4.92 +/- 1.36 1 (means +/- SD). Steady-state was reached 3 to 6 h after infusion started. The maximal DS plasma concentration was 16.4 +/- 5.7 micrograms/ml. Maximal APTT prolongation over pre-infusion values was 42 +/- 7%; TCT performed with bovine and human thrombin was prolonged by 16 +/- 7% and 83 +/- 35% respectively. No anti-IIa or anti-Xa activities were detected by chromogenic tests. The treatment was well tolerated. The pharmacokinetics of MF 701 infusion are consistent with those previously described after i.v. bolus administration. The infusion of MF 701 allows fast achievement and steady maintenance of elevated DS plasma concentrations.

The effect of dermatan sulfate on in vitro human plasma coagulation, platelet aggregation and beta TG/PF4 release.

We evaluated the in vitro anticoagulant action of dermatan sulfate (DS) (aPTT, antiXa, anti-thrombin) and its effect on human platelet aggregation and beta TG/PF4 release induced by threshold doses of aggregating agents, compared with standard heparin (SH). In pooled plasma, DS prolonged aPTT much less than SH, had no measurable antiXa activity, showed an anti-thrombin activity similar to that shown by SH at a tenfold higher dilution. DS had no direct effect on human platelet aggregation and beta TG/PF4 release. Moreover it did not significantly affect platelet aggregation and release by ADP and collagen, whereas it completely inhibited platelet aggregation and beta TG/PF4 release by thrombin. These data in vitro confirm that thrombin inhibition induced by DS is accompanied by a far lesser aPTT prolongation compared to heparin, without any appreciable interference with platelet function.

Pharmacodynamics and pharmacokinetics of dermatan sulfate in humans.

Dermatan sulfate (DS), a catalyst of the thrombin-heparin cofactor II interaction, has antithrombotic activity and is devoid of significant hemorrhagic risk in several animal models. We investigated the pharmacodynamic and pharmacokinetic properties of DS in humans. DS was injected in single bolus intravenous injections of four increasing doses (0.5, 1, 1.5, 2 mg/kg) to six healthy volunteers. The resulting anticoagulant activities were assessed by the activated partial thromboplastin time (APTT) and the thrombin clotting time (TCT). There were dose-dependent prolongations of the APTT and TCT, and the anticoagulant activities disappeared in less than three hours. The pharmacokinetic parameters were calculated from the plasma concentrations of DS measured with a new chromogenic assay. The volume of distribution was approximately 1.8 times greater than the theoretical plasma volume and was independent of dose. In contrast, the clearance decreased with dose and the terminal half-life ranged from 0.45 +/- 0.08 hours at 0.5 mg/kg to 0.72 +/- 0.11 hours (mean +/- SD) at 2 mg/kg. The bioavailabilities of subcutaneous (SC) and intramuscular (IM) administration relative to those of intravenous administration were determined in 12 other volunteers. The respective bioavailabilities were 24.7% +/- 12.9% and 12.4% +/- 9.2% for SC and IM administration. There was no detectable change in the APTT and the TCT when the volunteers were injected with 1.5 mg/kg SC or IM. In addition, the pharmacokinetic parameters derived from plasma concentrations of DS showed considerable interindividual variations by the two later routes of administration. Peak concentrations were noted 2.7 +/- 1.3 hours after SC injection and 4.3 +/- 4.9 hours after IM injection. The average peak concentrations were 0.7 +/- 0.3 and 0.4 +/- 0.2 mg/L after SC and IM injections, respectively. The half-lives of DS were 7.9 +/- 6.5 hours (SC) and 6.3 +/- 7.4 hours (IM). No adverse reaction to DS was recorded during this study.