ATC Code BO1 AB 04: Antithrombotics
Dalteparin sodium is a low molecular weight heparin fraction (weight average molecular weight of 6000 Daltons (range between 5,600 and 6,400 Daltons)) produced from porcine-derived heparin sodium.
Mechanism of action
Dalteparin sodium is an antithrombotic agent, which acts mainly through its ability to potentiate the inhibition of Factor Xa and thrombin by antithrombin. It has a relatively higher ability to potentiate Factor Xa inhibition than to prolong plasma clotting time (APTT).
Pharmacodynamic effects
Compared with standard, unfractionated heparin, dalteparin sodium has a reduced adverse effect on platelet function and platelet adhesion, and thus has only a minimal effect on primary haemostasis. Still some of the antithrombotic properties of dalteparin sodium are thought to be mediated through the effects on vessel walls or the fibrinolytic system.
Clinical efficacy and safety
The randomized, open-label, controlled, multicenter CLOT study (Randomized Comparison of Low-Molecular Weight Heparin Versus Oral Anticoagulant Therapy for Long Term Anticoagulation in Cancer patients with Venous Thomboembolism) compared dalteparin to standard oral anticoagulant .(OAC) therapy in the long term treatment of venous thromboembolism (VTE) in 676 patients with active malignancy who had experienced an acute symptomatic VTE (deep venous thrombosis (DVT) and/or a pulmonary embolism (PE)).
Patients were randomized to one of two groups:
- dalteparin arm prescribed at 200 IU/kg/day administered by subcutaneous (SC) injections (maximum 18,000 IU/day) during 1 month, then approximately 150 IU/kg/day from 2nd – 6th month, or
- VKA arm prescribed during 6 months (target INR 2-3), preceded by SC dalteparin 200 IU/kg/day OD (maximum 18,000 IU/day) during 5 to 7 days.
The most frequent diagnoses were: tumors of the gastrointestinal tract and pancreas (23.7%), genitourinary tumors (prostate, testicle, cervix, uterus, ovary and bladder) (21.5%), breast (16.0%), lung (13.3%). 10.4% of patients had haematological malignancies ; 75.1% of patients had metastatic disease.
The index VTE event was DVT alone in nearly 70% and PE with or without DVT in 30% of patients.
The primary endpoint was the time to first recurrence of symptomatic VTE (DVT and/or PE) during 6 months.
A total of 27 patients of 338 (8.0%) in the dalteparin arm and 53 patients of 338 (15.7%) in the VKA arm experienced at least one of the events of the composite primary endpoint. A significant 52% risk reduction in VTE recurrence at 6 months was seen with dalteparin (RR= 0.48, 95% CI [0.30-0.77], p=0.0016).
In the dalteparin arm, 19 patients (5.6%) experienced at least one episode of major bleeding compared to 12 patients (3.6%) in the VKA arm. The cumulative probability of experiencing a major bleeding at 6 months was respectively 6.5% and 4.9%, respectively. Any bleeding occurred with a higher frequency in the VKA arm (18.5% VKA vs 13.6% dalteparin). The comparison of the cumulative probability of first bleeding episode for the 2 treatments was of statistical significance in favour of dalteparin treatment (p=0.0487).
There was no significant difference in mortality between the two groups in deaths at 6 and 12 months (131 vs. 137 and 190 vs. 194 in the dalteparin and VKA arms, respectively).
There was no significant difference in the assessment of Quality of Life between the two groups of treatment.
Paediatric population
Treatment of symptomatic venous thromboembolism (VTE) in paediatric patients
An open-label, multi-centre, Phase 2 clinical trial studied 38 paediatric patients with objectively diagnosed acute deep vein thrombosis (DVT) and/or pulmonary embolism (PE). (24 males; 14 females) representing 5 age cohort groups, with cancer (N=26) and without cancer (N= 12). A total of 26 patients completed the study and 12 prematurely discontinued (4 due to adverse events, 3 patients withdrew consent and 5 for other reasons). The patients were treated with dalteparin twice daily for up to 3 months, with starting doses by age and weight and using a dose adjustment increment of 25 IU/kg.
The efficacy of the treatment in terms of regression, progression, resolution or no change in the qualifying VTE was assessed by imaging modalities at screening and at the end of the study (EOS).
At study completion (N=34), 21 (61.8%) patients had achieved resolution of the qualifying VTE; 7 (20.6%) patients showed regression, 2 (5.9%) patients showed no change, no patients showed progression and 4 (11.8%) patients did not contribute data for this analysis. In addition, 1 (2.9%) patient experienced a new VTE during the study.
The median doses of dalteparin (IU/kg) required to achieve a therapeutic anti-Xa level (0.5 to 1.0 IU/ml) during the 7-day dose adjustment period are presented in Table 1. Therapeutic anti-Xa levels (0.5 to 1.0 IU/ml) were achieved within (mean) 2.6 days. Bleeding events in patients who received at least one dose of study drug (N=38) included 1 (2.6%) major bleeding event; 0 (0%) clinically relevant non-major bleeding events; 16 (42.1%) minor bleeding events; and 14 (36.8%) patients had no bleeding events.
Table 1 - Median maintenance doses of dalteparin (IU/kg) after dose adjustment (using 25 IU/kg increments) associated with therapeutic anti-Xa level (0.5 to 1.0 IU/ml) by age cohort (N=34)
| Age cohort | N | Median dose (IU/kg) |
| 0 to less than 8 weeks | 0 | N/A |
| Greater than or equal to 8 weeks to less than 2 years | 2 | 208 |
| Greater than or equal to 2 years to less than 8 years | 8 | 128 |
| Greater than or equal to 8 years to less than 12 years | 7 | 125 |
| Greater than or equal to 12 years to less than 19 years | 17 | 117 |
A prospective, multi-centre, randomised, controlled clinical trial evaluated the duration of therapy for thrombosis in 18 children (0 to 21 years) receiving dalteparin anticoagulant treatment twice daily and determined the dalteparin dose per kilogram required to achieve an anti-Xa level of 0.5-1.0 IU/ml at 4-6 hours post-dose, by age group (pre-specified as infants <12 months, children 1 - <13 years, and adolescents 13 - <21 years).
The results from this study showed that median (range) therapeutic doses by age group were as follows: infants (n=3), 180 IU/kg (146-181 IU/kg); children (n=7), 125 IU/kg (101-175 IU/kg); and adolescents (n=8), 100 IU/kg (91-163 IU/kg).
A retrospective analysis reviewed the clinical and laboratory outcomes of prophylactic and therapeutic use of dalteparin in children (0 - 18 years old) in a single institution (Mayo Clinic) for VTE treatment from 1 December 2000 through 31 December 2011.
Treatment data for a total of 166 patients were reviewed, including 116 patients who received prophylactic doses of dalteparin and 50 patients who received therapeutic doses.The 50 patients receiving therapeutic doses, either once or twice per day, included 13 patients under 1 year of age and 21 patients with malignancies. The results showed that patients under 1 year of age required significantly higher weight-based dosage to achieve therapeutic anti-Xa levels compared to children (1-10 years) or adolescents (>10-18 years) (mean dose units/kg/day; 396.6 versus 236.7 and 178.8 respectively, p < 0.0001).
Of the 50 children treated in this retrospective study, 17 were infants under 2 years of age (mean age 6 months; 10/17 male). Most infants (12/17) were dosed twice a day with a median dalteparin starting dose of 151 IU/kg; (range 85 – 174 IU/kg); 5 infants were dosed only once a day, with similar doses. The 17 infants were treated for 1 to 3 months (median 2 months) and resolution of the VTE occurred in 82%; none experienced bleeding complications or ADR related to dalteparin.
Prophylaxis of venous thromboembolism in paediatric patients
A prospective study (Nohe et al, 1999) investigated the efficacy, safety and relation of dose to plasma anti-Xa activity of dalteparin in prophylaxis and therapy of arterial and venous thrombosis in 48 paediatric patients (32 males, 16 females; 31 weeks preterm to 18 years of age). Eight children with risk factors for thrombosis (obesity, protein C deficiency, carcinoma) received dalteparin for immobilization prophylaxis and 2 for “high risk” prophylaxis after cardiac surgery (group I). Thirty-six children received dalteparin therapeutically after arterial or venous thromboembolic events (groups II-IV). In the therapy group, 8/36 children (22%) were treated with dalteparin for reocclusion prophylaxis following successful thrombolytic therapy (group II), 5/36 (14%) following inferior failed thrombolytic therapy with rtPA or urokinase (group III) and 23/36 (64%) for primary antithrombotic therapy because of contraindications for thrombolysis (group IV).
In this study, 10 patients who received dalteparin for thromboprophylaxis required a maintenance dose of 95 ± 52 IU/kg subcutaneous (SC) once daily in order to achieve anti-Xa level of 0.2 to 0.4 IU/ml over a duration of 3 to 6 months. No thromboembolic events occurred in the 10 patients receiving dalteparin for thromboprophylaxis.