Development of Generic Low Molecular Weight Heparins: A Perspective

Pentosan Polysulfate Affords Pleotropic Protection to Multiple Cells and Tissues

Pentosan polysulfate (PPS), a small semi-synthetic highly sulfated heparan sulfate (HS)-like molecule, shares many of the interactive properties of HS. The aim of this review was to outline the potential of PPS as an interventional therapeutic protective agent in physiological processes affecting pathological tissues. PPS is a multifunctional molecule with diverse therapeutic actions against many disease processes. PPS has been used for decades in the treatment of interstitial cystitis and painful bowel disease, it has tissue-protective properties as a protease inhibitor in cartilage, tendon and IVD, and it has been used as a cell-directive component in bioscaffolds in tissue engineering applications. PPS regulates complement activation, coagulation, fibrinolysis and thrombocytopenia, and it promotes the synthesis of hyaluronan. Nerve growth factor production in osteocytes is inhibited by PPS, reducing bone pain in osteoarthritis and rheumatoid arthritis (OA/RA). PPS also removes fatty compounds from lipid-engorged subchondral blood vessels in OA/RA cartilage, reducing joint pain. PPS regulates cytokine and inflammatory mediator production and is also an anti-tumor agent that promotes the proliferation and differentiation of mesenchymal stem cells and the development of progenitor cell lineages that have proven to be useful in strategies designed to effect repair of the degenerate intervertebral disc (IVD) and OA cartilage. PPS stimulates proteoglycan synthesis by chondrocytes in the presence or absence of interleukin (IL)-1, and stimulates hyaluronan production by synoviocytes. PPS is thus a multifunctional tissue-protective molecule of potential therapeutic application for a diverse range of disease processes.

Efficacy and Safety of a Biosimilar Versus Branded Enoxaparin in the Prevention of Venous Thromboembolism Following Major Abdominal Surgery: A Randomized, Prospective, Single-Blinded, Multicenter Clinical Trial

Several biosimilar versions of enoxaparin are already approved and in use globally. Analytical characterization can establish good quality control in manufacturing, but they may not assure similarity in clinical outcomes between biosimilar and branded enoxaparin. This study evaluated the efficacy and safety of biosimilar Cristália versus branded Sanofi enoxaparin in venous thromboembolism (VTE) prevention in patients undergoing major abdominal surgery at risk for VTE. In this randomized, prospective single-blind study, we compared Cristália enoxaparin (Ce), a biosimilar version, versus branded Sanofi enoxaparin (Se; at a dose of 40 mg subcutaneously per day postoperatively from 7 to 10 days) in 243 patients submitted to major abdominal surgery at risk for VTE for VTE prevention. The primary efficacy outcome was occurrence of VTE or death related to VTE. The principal safety outcomes were a combination of major bleeding and clinically relevant non-major bleeding. Bilateral duplex scanning of the legs was performed from days 10 to 14, and follow-ups were performed up to 60 days after surgery. The incidence of VTE was 4.9% in the Cristália group and 1.1% in the Sanofi group (absolute risk difference = 3.80%, 95% confidence interval [CI]: −1.4%-9.0%) yielding noninferiority since the 95% CI does not reach the prespecified value Δ = 20%. Clinically significant bleeding occurred in 9.9% in the Cristália group and in 5.5% in the Sanofi group (n.s. ). In conclusion, this study suggests that 40 mg once daily of Ce, a biosimilar enoxaparin, is as effective and safe as the branded Sanofi enoxaparin in the prophylaxis of VTE in patients submitted to major abdominal surgery at risk for VTE.

Product Individuality of Commercially Available Low-Molecular-Weight Heparins and Their Generic Versions: Therapeutic Implications

The currently available brand-name low-molecular-weight heparins (LMWHs) in the United States include dalteparin (Pfizer), enoxaparin (Aventis), and tinzaparin (Pharmion). Other products available, in Europe, include certoparin (Novartis), reviparin (Abbott), nadroparin (GlaxoSmithkline), and parnaparin (Alpha-Wasserman). Each of these LMWHs has a characteristic molecular weight profile and biological activity in terms of an anti-FXa and anti-FIIa potency. The mean molecular weight of these drugs ranges from 4.0 kDa to 7.0 kDa and the anti-FXa:anti-FIIa ratio ranges from 1.5 to 3.5. These agents may also be characterized by the presence of specific chemical end groups such as 2-O-sulfo-4-enepyranosuronic acid at the nonreducing terminus (enoxaparin) or 2,5-anhydro-D-mannose at the reducing terminus (dalteparin). Further, the component oligosaccharide chains exhibit product-specific distribution profiles. It is now widely accepted that individual LMWHs are chemically unique agents and cannot be interchanged therapeutically. Each commercial LMWH has been individually developed for specific clinical indications, which are dose and product dependent. Recently, several generic LMWHs have become available in India (Cutenox and Markaparin) and South America (dilutol, clenox, dripanina), and three companies have filed for regulatory approval of a generic version of enoxaparin in the United States. As the primary aim of a generic drug is to reduce cost without compromising patient care, a generic drug is required to be chemically and biologically equivalent to the pioneer drug. Because LMWHs represent complex natural mucopolysaccharide drugs that have undergone chemical and enzymatic modifications, physicochemical and biological information in addition to molecular weight and anti-FXa:anti-FIIa ratio should be used to determine generic equivalency to the branded drug. We have utilized a previously reported approach to systematically compare three generic versions of enoxaparin obtained from India and Brazil with the branded enoxaparin (Lovenox) available in the United States. Testing included molecular and structural profiling, evaluation in clot-based and amidolytic anti-FXa and anti-FIIa assays, and heparinase-I digestion profiles. While the molecular profiles (4.8 ± 1.8kD) and anticoagulant potencies as determined by activated partial thromboplastin time (APTT) were comparable for all four agents, the generic products showed variations in the thrombin time (TT) and Heptest assays. Two generic and the branded enoxaparin were readily digested by heparinase-I, losing most of their anticoagulant activity, but one generic product resisted digestion. This may have been due to a unique structural feature in this product. These studies show that, while generic LMWHs may exhibit acceptable molecular weight and anti-FXa profiles, they can exhibit assay-based differences and digestion profiles. Testing in animal models to determine safety, efficacy, and pharmacodynamic parameters may be important to verify equivalence. In order to assure that the generic LMWHs are equivalent to branded LMWHs such that equivalent clinical results are obtained, there is a need to develop clear stepwise guidelines that will establish equivalency in terms of physical, chemical, biochemical, pharmacokinetic, and pharmacodynamic properties for these anticoagulant drugs.

Generic Versus Branded Enoxaparin in the Prevention of Venous Thromboembolism Following Major Abdominal Surgery

Introduction: Several generic low-molecular-weight heparins (LMWHs) have recently become available worldwide, including the United States. Companies have filed for regulatory approval of generic versions in many countries, based only on compound biochemical characteristics or its immunogenicity. Methods: Prospective study to evaluate the comparative effect of 2 enoxaparins (Sanofi-Aventis branded enoxaparin [SAe] vs eurofarma-enoxaparin [Ee], a generic version) as prophylaxis for venous thromboembolism (VTE) following major abdominal surgery. A total of 200 patients were randomized in a 1:1 ratio either to receive 40 mg of SAe or Ee subcutaneously (sc) once daily (od) postoperatively for 7 to 10 days. Compressive ultrasound was performed on day 10 + 4. Results: No statistically significant differences between the 2 groups were detected. In all, 2 SAe patients presented deep vein thrombosis ([DVT] 2.1%), none of the Ee group. No major bleeding events occurred. Conclusions: This exploratory trial suggests that the generic LMWH is probably as safe and as effective as the branded enoxaparin (Lovenox, Brazil) in the prophylaxis of VTE in this population.

Recurrent life-threatening deep tissue hematomas after switching to generic enoxaparin: a report and perspective on the approval process for biological compounds

In the United States, the Food and Drug Administration (FDA) has allowed makers of biologic therapies to use the abbreviated new drug application, which does not require safety and efficacy studies. Instead this relies on proving equivalency with the original compound and demonstrating in vitro activity and similar pharmacodynamics. In the United States, a low-molecular-weight heparin, enoxaparin, was recently approved in a generic format through the abbreviated new drug application. We present a patient treated with branded enoxaparin for 4 years with no complications. After the switch to the generic enoxaparin, the patient developed 2 life-threatening hemorrhages within 4 months of the initiation of the compound. This case suggests that the FDA should follow the European Medicine Administration (EMA) guidance by tightening its approval process for generic bioequivalents and requiring studies demonstrating similar safety and efficacy as the parent compound, prior to approval of a generic biologically active compound.

New and Generic Anticoagulants and Biosimilars: Safety Considerations

The recent health care changes and approval of a generic low-molecular-weight heparin (LMWH) by the US Food and Drug Administration (FDA) merit a review of the facts regarding the new and generic anticoagulants. Fatal hypotension from anaphylactoid type reactions following heparin administration was responsible for more than 149 deaths all over the world. Researchers detected a heparin-like semisynthetic contaminant, over-sulfated chondroitin sulfate (OSCS), that appeared to be intentional. Low-molecular-weight heparins are produced using unfractionated heparin and OSCS has been found in various batches of LMWHs. Some newer anticoagulants are claiming to be free from the need to monitor for therapeutic effect and bleeding risk. Therefore, monitoring assays are not being developed and there is no antidote to reverse bleeding. In addition, there are concerns about reproducibility, product variation, and quality. In conclusion, although the generic LMWHs and newer anticoagulants may appear to be effective for qualified indications, their safety remains to be a concern.

Treatment of Cancer-Associated Thrombosis: Distinguishing Among Antithrombotic Agents

The risk of cancer-associated thrombosis can be substantial, depending on tumor type, extent of cancer, and type of treatment. Unfractionated heparin and warfarin have been used in the prevention of cancer-associated thrombosis, but low-molecular-weight heparin (LMWH) is widely used for the prevention of venous thromboembolism in high-risk patients. Long-term management with warfarin is associated with close monitoring, an increased risk of drug interactions, and bleeding. LMWHs may offer an alternative outpatient treatment strategy for prophylactic treatment because of their simpler dosing, more predictable anticoagulant activity, and improved safety profile. Clinical trials examining the treatment of venous thromboembolism with LMWH in patients with cancer suggest a survival advantage for the treated groups. Subtle differences in the pharmacokinetics of available LMWHs exist, and each LMWH should be regarded as a distinct drug. Pharmacists should be aware of the US Food and Drug Administration-approved uses for each LMWH, dosing options, and the advantages and disadvantages of available delivery systems for various patient populations. Pharmacists can play a major role in educating patients and other health care professionals on risk factor recognition, patient risk stratification, and proper agent selection for prevention and treatment of cancer-associated thrombosis.