Debate is around the optimal immunization regimen for cancer vaccines since too intense vaccination schedules may exhaust reactive lymphocytes. GX301 is a telomerase-based cancer vaccine whose safety and immunological effects were tested in a phase I trial applying an eight administrations schedule. Main objective of this study was to comparatively analyse safety and immunological response to three GX301 regimens in metastatic castration-resistant prostate cancer patients with response/disease stability after docetaxel chemotherapy. This was a multicentre, randomized, parallel-group, open-label trial registered with EudraCT (2014-000095-26) and ClinicalTrials.gov (NCT02293707, 2014). Ninety-eight patients were randomized to receive either eight (regimen 1), four (regimen 2) or two (regimen 3) vaccine administrations. Sixty-three patients were assessable for the primary immunological end-point. Vaccine-specific immune responses were evaluated by intracellular staining for IFN, elispot and cytotoxic assay at 90 and 180 days from baseline. No major side effects were recorded. A 54% overall immune responder rate was observed with 95% of patients showing at least one vaccine-specific immune response. Rate of immunological responders and number of immunizations were proportionally related, suggesting superiority of regimens 1 and 2 over regimen 3. Overall survival did not differ among regimens in both immunological responders and non-responders and was inversely associated (P = 0.002) with increase in the number of circulating CD8 + T regulatory cells at 180 days. These data indicate that GX301 cancer vaccine is safe and immunogenic in metastatic castration-resistant prostate cancer patients. Schedules with high number of administrations should be preferred in future studies due to their better immunological outcome.

OBJECTIVE:To assess the pharmacokinetics and effects on blood coagulation of dermatan sulfate (DS), a glycosaminoglycan with antithrombotic properties, following intravenous and single and repeated intramuscular administrations. The mean molecular weight of DS is currently 22kD, i.e. 5kD lower than batches used in the early development of the compound.SUBJECTS AND METHODS:Each of 14 male healthy volunteers received DS 300mg as an 8-hour intravenous infusion and as single and repeated (once daily for 9 days) intramuscular injections. Nine of the same subjects were also given DS 100mg and 200mg as single intramuscular doses. Plasma DS concentrations were measured with a specific chromogenic assay. Activated partial thromboplastin time (aPTT) and thrombin clotting time (TCT) responses were also determined.RESULTS:The mean +/- SD volume of distribution and terminal half-life of DS were 6.0 +/- 1.4L and 0.9 +/- 0.2h after intravenous infusion. Maximum plasma concentration (C(max)) and area under the plasma concentration-time curve after single intramuscular injections were dose-proportional. After repeated intramuscular administration, steady state was reached by day 3. On day 9, plasma DS fluctuated between 4.3 +/- 1.5 (C(max)) and 0.9 +/- 0.4 (minimum plasma concentration at steady state) mg/L, time to C(max) was 3.4 +/- 0.8h, terminal half-life was 12.2 +/- 4.1h and the accumulation factor was 2.0 +/- 0.5. Geometric mean bioavailability of intramuscular DS was 54% and 79% after single and repeated 300mg administration, respectively. aPTT and TCT responses were both linearly related to plasma DS concentrations, with TCT showing greater responsivity.CONCLUSION:As compared with earlier DS studies, the present data showed a greater extent of DS absorption after single intramuscular administration and a faster absorption rate after repeated dosing, and provided evidence of dose-response predictability. These findings may explain the improved antithrombotic efficacy of DS observed in a recent clinical trial.

Summary 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 out-patients 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.

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.

Summary 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 [DVT] 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.

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.

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.

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.

SummaryTwo 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 μ/ml are advisable to optimize efficacy in hip fracture patients.

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.

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.

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.