A review of the two major regulatory pathways for non-proprietary low-molecular-weight heparins

Heparin and Related Substances for Treating Diabetic Foot Ulcers: A Systematic Review and Meta-Analysis

BACKGROUND

Diabetic foot ulcers are a major complication of diabetes mellitus (DM), when heparin and heparin related substances may be potentially used as an adjuvant treatment. We aimed to evaluate the efficacy and safety of heparin and heparin related substances for the treatment of diabetic foot ulcers.

METHODS

We searched up to March 2021 in the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; EBSCO CINAHL; VIP Chinese Science and Technique Journals Database; China National Knowledge Infrastructure (CNKI) Database and Wan Fang Database investigating heparin or heparin-related substances in patients with diabetic foot ulcers. The primary outcomes included proportion of ulcers completely healed and time to complete ulcer healing. We assessed each included study with the Cochrane 'Risk of bias' tool and used the GRADE approach to assess the overall quality of the evidence.

RESULTS

We included nine randomized studies involving 620 participants in the meta-analysis, involving two different heparin and heparin-related substances, low molecular weight heparin (LMWH) and hyaluronic acid. Our study did not show the benefits from LMWH on increasing chance of the ulcer healing (RR: 1.26; 95% CI: 0.78 to 2.04; P=0.35; very low) or shortening the time to complete ulcer healing (SMD: 0.13 d; 95% CI: -0.29 to 0.56; P=0.54; very low). Hyaluronic acid may improve the complete ulcer healing (RR: 1.57; 95% CI: 1.29 to 1.91; P˂0.00001; very low) and shorten the time to complete ulcer healing (SMD -0.84, 95% CI -1.15 to -0.53; P<0.00001; low). Hyaluronic acid and LMWH were generally well tolerated for treating diabetic foot ulcers in this review.

CONCLUSION

Hyaluronic acid may improve diabetic foot ulcer with very low quality evidence but not LMWH. However, the benefits and harms need further validation in larger trials with different population.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero/], identifier [PROSPERO, CRD42021269212].

Pharmacodynamic properties and bioequivalence of dalteparin sodium subcutaneous injection in healthy Chinese male subjects

1. Dalteparin sodium (DS) is a low molecular weight heparin that is widely used in the treatment of thromboembolism. The purpose of this study was to compare the pharmacodynamic properties and bioequivalence of the two formulations of DS with subcutaneous injection in healthy Chinese male subjects. 2. In this randomized, open-label, two-period crossover study, a total of 24 male subjects were recruited to receive single subcutaneous doses of test and reference DS injection in two different sequences (12 subjects each) with a seven-day washout period. Plasma samples were obtained at different time points after administration of the injection and measured by chromogenic substrate assay. The pharmacodynamic parameters including E_max, AUEC_0-T, AUEC_0-∞ and T_max were analyzed to evaluate the bioequivalence of two DS formulations. 3. The relative bioequivalence was 107.7 ± 15.5 and 106.6 ± 29.8 for Anti-Xa and Anti-IIa, two major active metabolites of DS, respectively. The 90% confidence intervals (CIs) of the geometric mean ratio (test/reference) of E_max, AUEC_0-T and AUEC_0-∞ were 98.71-104.40%, 101.95-112.13% and 102.38-112.10% for Anti-Xa, and 100.88-110.42%, 95.76-112.62% and 92.24-111.32% for Anti-IIa, respectively, and all of the 90% CIs were within 80-125%. The T_1/2 of reference and test were 2.88 ± 1.21 h and 2.76 ± 0.97 h for Anti-Xa, 1.87 ± 0.62 h and 1.96 ± 1.52 h for Anti-IIa. 4. Based on the pharmacodynamic parameters and FDA Guidance on DS and regulatory criteria for bioequivalence, the test and reference formulations were bioequivalent in healthy Chinese male subjects.

Characterization of the antithrombotic fingerprint of the branded and copies of the low-molecular-weight enoxaparin using thrombin generation assay

BACKGROUND

The patent protection of low-molecular-weight heparins (LMWHs) expired, so the definition of criteria for the biological similarity between LMWH copies and the original product is a real need.

AIM

The present in vitro study compared copies and branded enoxaparin using the specific anti-Xa activity and the calibrated automated thrombogram assay.

METHODS

Samples of platelet-poor plasma (PPP) and platelet-rich plasma (PRP) from 15 healthy volunteers were spiked with branded enoxaparin (Lovenox) or its copies (Cutenox, Dilutol, Enoxa, Fibrinox, Loparin, Lupenox, Novex, Noxprin, and Versa). The specific anti-Xa activity was measured in PPP, and thrombin generation was assessed in PPP and PRP in the presence of tissue factor or pancreatic cancer cells BXPC3.

RESULTS

The anti-Xa activity of enoxaparin copies ranged from 0.072 to 0.088 IU/μg, being lower as compared to the branded enoxaparin (0.095 anti-Xa IU/μg). The potency of each copy to inhibit thrombin generation varied in the 3 experimental systems. The presence of platelets or pancreatic cancer cells BXPC3 in human plasma induced significant modifications in the inhibitory efficiency of enoxaparin copies on thrombin generation, which distinguished them from the branded product.

CONCLUSION

Enoxaparin copies showed significant variability regarding their inhibitory potency on thrombin generation. Platelets and cancer cells significantly increased the variability of the antithrombotic efficiency of the copies as compared to the branded enoxaparin. The present study underlines the need for the elaboration of additional functional criteria to evaluate the global antithrombotic capacity of enoxaparin copies in order to evaluate their potential sameness with the branded drug.

Active and passive surveillance of enoxaparin generics: a case study relevant to biosimilars

OBJECTIVE

This retrospective analysis assessed the capability of active and passive safety surveillance systems to track product-specific safety events in the USA for branded and generic enoxaparin, a complex injectable subject to immune-related and other adverse events (AEs).

METHODS

Analysis of heparin-induced thrombocytopenia (HIT) incidence was performed on benefit claims for commercial and Medicare supplemental-insured individuals newly treated with enoxaparin under pharmacy benefit (1 January 2009 - 30 June 2012). Additionally, spontaneous reports from the FDA AE Reporting System were reviewed to identify incidence and attribution of enoxaparin-related reports to specific manufacturers.

RESULTS

Specific, dispensed products were identifiable from National Drug Codes only in pharmacy-benefit databases, permitting sensitive comparison of HIT incidence in nearly a third of patients treated with brand or generic enoxaparin. After originator medicine's loss of exclusivity, only 5% of spontaneous reports were processed by generic manufacturers; reports attributable to specific generics were approximately ninefold lower than expected based on market share.

CONCLUSIONS

Claims data were useful for active surveillance of enoxaparin generics dispensed under pharmacy benefits but not for products administered under medical benefits. These findings suggest that the current spontaneous reporting system will not distinguish product-specific safety signals for products distributed by multiple manufacturers, including biosimilars.

Bioequivalence study of two subcutaneous formulations of dalteparin: randomized, single-dose, two-sequence, two-period, cross-over study in healthy volunteers

Objective

This study assessed relative bioavailability of a new subcutaneous formulation, test (T) (dalteparin sodium 95000 IU/3.8 mL) with the branded product (R) in healthy subjects to meet the regulatory requirements of bioequivalence in the US.

Methods

This was an open label, randomized, single dose, two-sequence, two-period cross-over study under fasting conditions. A total of 88 healthy adult volunteers were randomized to either of the treatment arms (T or R) separated by a washout period of 7 days. Pharmacodynamic surrogates, namely anti-Xa and anti-IIa activity, heparin clotting assay (heptest), and activated partial thromboplastin time (aPTT) were used as a tool to establish bioequivalence between these two formulations. Blood samples were collected up to 36 h post-dose to characterize the primary pharmacokinetic parameters A_max, AUC_0–t, and AUC_0–∞ for anti-Xa and anti-IIa and heptest; parameters (Δt )_max and AU(Δt ) for aPTT.

Results

For anti-Xa activity, the means (SD) of A_max (IU/mL) were 1.34 (0.25) [range = 0.59–2.03] and 1.39 (0.35) [range = 0.65–2.69]; AUC_0–t (IU•h/mL) values were 11.4 (2.76) [range = 2.89–19.5] and 12.1 (2.87) [range = 2.52–21.30]; AUC_0–∞ (IU•h/mL) values were 13.1 (3.59) [range = 3.15–28.2] and 14.5 (4.97) [range = 2.79–36.1] for test and branded formulations, respectively. For anti-IIa activity, the means (SD) of A_max (IU/mL) were 0.34 (0.12) [range = 0.14–0.72] and 0.34 (0.13) [range = 0.11–0.84]; AUC_0–t (IU•h/mL) values were 2.05 (0.72) [range = 0.61–4.69] and 2.11 (0.76) [range = 0.84–4.80]; AUC_0–∞ (IU•h/mL) values were 2.47 (0.80) [range = 0.76–6.29] and 2.61 (0.86) [range = 1.31–5.36], for test and branded formulations, respectively. The 90% CI for all the primary pharmacokinetic parameters of all the pharmacodynamic surrogates tested met the regulatory bioequivalence criterion of 80.00–125.00%.

Conclusion

The test product met the US regulatory criteria of bioequivalence relative to the branded product in this single dose bioequivalence study. Study limitations include open-label single dose design.