Comparative studies on branded enoxaparin and a US generic version of enoxaparin

Comparative Studies on the Anticoagulant Profile of Branded Enoxaparin and a New Biosimilar Version

Low molecular weight heparins (LMWH) represent depolymerized heparin prepared by various methods that exhibit differential, biochemical and pharmacological profiles. Enoxaparin is prepared by benzylation followed by alkaline depolymerization of porcine heparin. Upon the expiration of its patent, several biosimilar versions of enoxaparin have become available. Heparinox (Sodic enoxaparine; Cristália Produtos Químicos Farmacêuticos LTDA, Sao Paulo, Brazil) is a new biosimilar form of enoxaparin. We assessed the molecular weight and the biochemical profile of Heparinox and compared its properties to the original branded enoxaparin (Lovenox; Sanofi, Paris, France). Clotting profiles compared included activated clotting time, activated partial thromboplastin time (aPTT), and thrombin time (TT). Anti-protease assays included anti-factor Xa and anti-factor IIa activities. Thrombin generation was measured using a calibrated automated thrombogram and thrombokinetic profile included peak thrombin, lag time and area under the curve. USP potency was determined using commercially available assay kits. Molecular weight profiling was determined using high performance liquid chromatography. We determined that Heparinox and Lovenox were comparable in their molecular weight profile. Th anticoagulant profile of the branded and biosimilar version were also similar in the clot based aPTT and TT. Similarly, the anti-Xa and anti-IIa activities were comparable in the products. No differences were noted in the thrombin generation inhibitory profile of the branded and biosimilar versions of enoxaparin. Our studies suggest that Heparinox is bioequivalent to the original branded enoxaparin based upon in vitro tests however will require further in vivo studies in animal models and humans to determine their clinical bioequivalence.

Comparison of Efficacy and Safety of Two Different Enoxaparin Products in Prevention of Venous Thromboembolism Following Major Obstetric-gynecological Surgeries: An Open-label Randomized Clinical Trial

Venous thromboembolism (VTE) occurs in about 5 percent of patients undergoing major abdominal surgeries. Prophylaxis of VTE is recommended using unfractionated heparin (UF) or low molecular weight heparin (LMWH) in high-risk patients. In spite of advantages and confirmed cost-effectiveness of LMWH, high costs of enoxaparin branded preparations limit its use. We aimed to compare the efficacy and safety of two enoxaparin preparations. In this open-label randomized clinical trial, 200 patients were recruited to recieve PDxane® or Clexane®, 40 mg subcutaneously daily, from the day of surgery for 10 days. The patients were evaluated for VTE occurrence and side effects considering clinical and laboratory examinations at the beginning and day 10. No cases of proximal or distal VTE or life threatening bleeding were observed among 102 and 98 patients who received PDxane® and Clexane®, respectively. The adverse effects observed in PDxane® and Clexane® groups included injection site reactions (rash: P = 0.97; pain: P = 0.55 and erythema: P = 0.33), anemia (P = 0.32), hematuria (P = 0.16), confusion (P = 0.3), and increased liver transaminases (AST ≥ 3 × ULN: P = 0.16 and ALT ≥ 3 × ULN: P = 0.66). In according to the study results PDxane® was of similar efficacy and safety compared to Clexane® in preventing VTE following major obstetric-gynecological surgeries. Considering lower cost of PDxane®, it could be a safe and effective alternate for VTE prophylaxis in the patients undergoing such types of surgeries.

Update on Brazilian biosimilar enoxaparins

INTRODUCTION

Brazil is among the first countries approving the commercialization and clinical use of biosimilar enoxaparins. Our research group has performed quality control assessments of these drugs over the last decade. Areas covered: We have not found noticeable differences between Brazilian biosimilar enoxaparins and the original product regarding their physicochemical properties, disaccharide composition, anticoagulant activity, bioavailability and safety. Expert commentary: In spite of clinical and pharmacological advantages of enoxaparin, subcutaneous formulations of unfractionated heparin are employed by the Brazilian public health system for prevention and treatment of thromboembolism. The underuse of both original and biosimilar enoxaparins in Brazil directly correlates with their high cost.

Comparative studies on biological activity of generic and branded enoxaparin in vivo and vitro

As per US Food and Drug Administration (FDA) requirement, the study was designed to conduct the fourth and fifth criteria of Abbreviated New Drug Application to demonstrate equivalence of generic and branded Enoxaparin in vivo and vitro.Pharmacodynamic behavior of branded and generic Enoxaparin was compared in a parallel study in rats based upon measurement of anti-FXa and anti-FIIa profiles. Blood samples collected at baseline and at 0.5, 1, 2, 4, 6, 8, 12 and 24 h postsubcutaneous administration of six batches of Lovenox and nine batches of generic Enoxaparin were evaluated for anti-FXa and anti-FIIa using chromogenic substrate method. Anti-FXa, Anti-FIIa, activated partial thromboplastin time (APTT), and Heptest prolongation time were conducted in vitro as per the United States Pharmacopeia method. Pharmacodynamics parameters were obtained including peak effect (anti-FXamax, anti-FIIamax), area under the effect curve (AUEC0-T and AUEC0-∞), Tmax, and T1/2.Pharmacokinetic differences were not observed using anti-FXa or anti-FIIa. No statistically significant differences were observed between branded and generic Enoxaparin either in vitro anti-FXa, anti-FIIa, APTT, or Heptest assay.It can be concluded that they are bioequivalent in anticoagulant activity tested in vivo and vitro.

Evaluation of Immunostimulatory Potential of Branded and US-Generic Enoxaparins in an In Vitro Human Immune System Model

Low-molecular-weight heparins (LMWHs) have several positive therapeutic effects and can also form immunostimulatory complexes with plasma proteins, such as platelet factor 4 (PF4). We compared the innate response and functional profiles of branded and US-generic enoxaparins from 2 manufacturers in either native or PF4-bound forms in an in vitro model of human immunity. In an analysis of 2 product lots from each manufacturer and multiple separate batches of protein–heparin complexes, branded enoxaparin was shown to be consistently nonstimulatory for innate responses, whereas US-generic enoxaparins generated variable immunostimulatory profiles depending on the enoxaparin lot used to prepare the PF4–LMWH complexes. Production of tissue factor pathway inhibitor (TFPI), a physiologic heparin-induced inhibitor of tissue factor-induced coagulation that was used as a functional readout of biological activity of enoxaparins in these assays, was heightened in the presence of branded enoxaparin complexes, but its levels were variable in cultures treated with complexes containing US-generic enoxaparins. Analytical analyses suggest that the heightened immunostimulatory potential of some of the US-generic enoxaparin product lots could be tied to their capacity to form ultra-large and/or more stable complexes with PF4 than the other LMWHs included in this study. Although these distinct biological and analytical profiles might be related to the composition and/or consistency of branded and US-generic enoxaparins included in our data set, further studies are warranted to elucidate the pathophysiological relevance of these in vitro findings.