Estudos de medicamentos biosimilares

In Brazil, the registration of new drugs is carried out only when the regulatory agency (Anvisa, acronym in Portuguese) is fully satisfied with the evidence of their quality, efficacy and safety, presented by a pharmaceutical industry that strive for this registration. With the patent expiration, pharmaceutical companies are attracted to produce biological medicines called biosimilar or biogenerics or simply generics, whose approval may result in reduced treatment costs. But it is necessary that the biosimilar be, at least, equally efective and safe and without contaminants in relation to the original. Recent consensus guidelines aim to establish criteria for efcacy and safety of these medicines. Preclinical studies in vitro and in vivo, the origin of raw materials and clinical studies phase I, II and III are recommended for biosimilar medicine registration in the international market. Low molecular weight heparins are found in this situation. In this review we specifcally addressed this type of medicine, which could serve as a benchmark for other biosimilar medicines.

Novos anticoagulantes para a profilaxia do tromboembolismo venoso em cirurgias ortopédicas de grande porte: revisão sistemática de ensaios clínicos randonizados

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thrombotic obstruction of the central venous catheter in patients undergoing hematopoietic stem cell transplantation

This is an integrative literature review with the aim of summarizing the prevention measures and treatment of thrombotic obstruction of long-term semi-implanted central venous catheters, in patients undergoing hematopoietic stem cell transplantation. The sample consisted of seven studies, being two randomized controlled clinical trials, three cohort studies and two case series. Regarding the prevention measures, one single study demonstrated effectiveness, which was a cohort study on the oral use of warfarin. In relation to the treatment measures, three studies evidenced effectiveness, one highlighted the efficacy of streptokinase or urokinase, one demonstrated the benefit of using low-molecular-weight heparin and the other treated the obstruction with heparin or urokinase. Catheter patency research shows a restricted evolution that does not follow the evolution of transplantations, mainly regarding nursing care.

Untersuchung zur Therapie akuter venöser Thromboembolien mit niedermolekularen Heparinen (NMH)

Über einen Zeitraum von 14 Monaten wurden Patienten mit akuter, duplexsonographisch nachgewiesener tiefer Beinvenenthrombose erfasst und im initialen Behandlungszeitraum mit niedermolekularem Heparin (Enoxaparin) sowie im weiteren Verlauf überlappend mit Marcumar® therapiert. Erhoben wurden eine ausführliche, standardisierte Eigen- sowie Familienanamnese und die Risikofaktoren für eine TVT. Desweiteren wurde eine klinische Untersuchung inklusive Duplexsonographie der Venen und eine Thrombophiliediagnostik durchgeführt. Täglich erfolgte die Bestimmung diverser Laborparameter (INR, APTT, D-Dimere, CRP, kleines Blutbild). Am ersten und fünften Tag wurden zusätzlich die Transaminasen bestimmt. Nach 30 Tagen erfolgte eine klinische Verlaufskontrolle, nach drei Monaten eine ambulante Kontrollduplexsonographie. Diskutiert werden Enoxaparin-Nebenwirkungen, Verläufe der duplexsonographisch erhobenen Befunde und klinischen Symptome, die Thrombophiliediagnostik sowie Laborverläufe der Infekt- und Gerinnungsparameter (APTT, INR, D-Dimere). Die D-Dimerverläufe und die Bedeutung der sinnvollen D-Dimerbestimmung wurden bereits auf mehreren Tagungen vorgestellt.

Usefulness of preemptive anticoagulation in patients with suspected pulmonary embolism: a decision analysis

The diagnostic workup of pulmonary embolism (PE) may take several hours. The usefulness of anticoagulant treatment while awaiting the results of diagnostic tests has not been assessed. The objective of this study was to compare the risks and benefits of bid low-molecular-weight heparin vs no treatment in patients with suspected PE.

The GPIb thrombin-binding site is essential for thrombin-induced platelet procoagulant activity

The role of the platelet glycoprotein (GP) Ib-V-IX receptor in thrombin activation of platelets has remained controversial although good evidence suggests that blocking this receptor affects platelet responses to this agonist. The mechanism of expression of procoagulant activity in response to platelet agonists is also still obscure. Here, the binding site for thrombin on GPIb is shown to have a key role in the exposure of negatively charged phospholipids on the platelet surface and thrombin generation, in response to thrombin, which also requires protease-activated receptor-1, GPIIb-IIIa, and platelet-platelet contact. Von Willebrand factor binding to GPIb is not essential to initiate development of platelet procoagulant activity. Inhibition of fibrinogen binding to GPIIb-IIIa also failed to block platelet procoagulant activity. Both heparin and low molecular weight heparin block thrombin-induced platelet procoagulant activity, which may account for part of their clinical efficacy. This study demonstrates a new, critical role for platelet GPIb in hemostasis, showing that platelet activation and coagulation are tightly interwoven, which may have implications for alternative therapies for thrombotic diseases.

Functional expression of CCR1, CCR3, CCR4, and CXCR4 chemokine receptors on human platelets

Platelets are known to contain platelet factor 4 and beta-thromboglobulin, alpha-chemokines containing the CXC motif, but recent studies extended the range to the beta-family characterized by the CC motif, including RANTES and Gro-alpha. There is also evidence for expression of chemokine receptors CCR4 and CXCR4 in platelets. This study shows that platelets have functional CCR1, CCR3, CCR4, and CXCR4 chemokine receptors. Polymerase chain reaction detected chemokine receptor messenger RNA in platelet RNA. CCR1, CCR3, and especially CCR4 gave strong signals; CXCR1 and CXCR4 were weakly positive. Flow cytometry with specific antibodies showed the presence of a clear signal for CXCR4 and weak signals for CCR1 and CCR3, whereas CXCR1, CXCR2, CXCR3, and CCR5 were all negative. Immunoprecipitation and Western blotting with polyclonal antibodies to cytoplasmic peptides clearly showed the presence of CCR1 and CCR4 in platelets in amounts comparable to monocytes and CCR4 transfected cells, respectively. Chemokines specific for these receptors, including monocyte chemotactic protein 1, macrophage inflammatory peptide 1alpha, eotaxin, RANTES, TARC, macrophage-derived chemokine, and stromal cell-derived factor 1, activate platelets to give Ca(++) signals, aggregation, and release of granule contents. Platelet aggregation was dependent on release of adenosine diphosphate (ADP) and its interaction with platelet ADP receptors. Part, but not all, of the Ca(++) signal was due to ADP release feeding back to its receptors. Platelet activation also involved heparan or chondroitin sulfate associated with the platelet surface and was inhibited by cleavage of these glycosaminoglycans or by heparin or low molecular weight heparin. These platelet receptors may be involved in inflammatory or allergic responses or in platelet activation in human immunodeficiency virus infection.

Safety of inferior vena cava filter retrieval in anticoagulated patients

PURPOSES: To evaluate the safety of inferior vena cava (IVC) filter retrieval in therapeutically anticoagulated patients in comparison to prophylactically or not therapeutically anticoagulated patients with respect to retrieval-related hemorrhagic complications. MATERIALS AND METHODS: This was a retrospective study of 115 consecutive attempted IVC filter retrievals in 110 patients. Filter retrievals were stratified as performed in patients who were therapeutically anticoagulated (group 1), prophylactically anticoagulated (group 2), or not therapeutically anticoagulated (group 3). The collected data included anticoagulant and antiplatelet medications (type, form and duration of administration, dosage) at the time of retrieval. Phone interviews and chart review was performed for the international normalized ratio (INR), activated partial thromboplastin time, platelet count, infusion of blood products, and retrieval-related hemorrhagic complications. RESULTS: Group 1 included 65 attempted filter retrievals in 61 therapeutically anticoagulated patients by measured INR or dosing when receiving low-molecular-weight heparin (LMWH). Four retrievals were not successful. In patients receiving oral anticoagulation, the median INR was 2.35 (range, 2 to 8). Group 2 comprised 23 successful filter retrievals in 22 patients receiving a prophylactic dose of LMWH. Group 3 included 27 attempted filter retrievals in 27 patients not receiving therapeutic anticoagulation. Six retrievals were not successful. Five patients were receiving oral anticoagulation with a subtherapeutic INR (median, 1.49; range, 1.16 to 1.69). No anticoagulation medication was administered in 22 patients. In none of the groups were hemorrhagic complications related to the retrieval procedures identified. CONCLUSIONS: These results suggest that retrieval of vena cava filters in anticoagulated patients is safe. Interruption or reversal of anticoagulation for the retrieval of vena cava filters is not indicated.

The adherence to initial processes of care in elderly patients with acute venous thromboembolism.

BACKGROUND We aimed to assess whether elderly patients with acute venous thromboembolism (VTE) receive recommended initial processes of care and to identify predictors of process adherence. METHODS We prospectively studied in- and outpatients aged ≥65 years with acute symptomatic VTE in a multicenter cohort study from nine Swiss university- and non-university hospitals between September 2009 and March 2011. We systematically assessed whether initial processes of care, which are recommended by the 2008 American College of Chest Physicians guidelines, were performed in each patient. We used multivariable logistic models to identify patient factors independently associated with process adherence. RESULTS Our cohort comprised 950 patients (mean age 76 years). Of these, 86% (645/750) received parenteral anticoagulation for ≥5 days, 54% (405/750) had oral anticoagulation started on the first treatment day, and 37% (274/750) had an international normalized ratio (INR) ≥2 for ≥24 hours before parenteral anticoagulation was discontinued. Overall, 35% (53/153) of patients with cancer received low-molecular-weight heparin monotherapy and 72% (304/423) of patients with symptomatic deep vein thrombosis were prescribed compression stockings. In multivariate analyses, symptomatic pulmonary embolism, hospital-acquired VTE, and concomitant antiplatelet therapy were associated with a significantly lower anticoagulation-related process adherence. CONCLUSIONS Adherence to several recommended processes of care was suboptimal in elderly patients with VTE. Quality of care interventions should particularly focus on processes with low adherence, such as the prescription of continued low-molecular-weight heparin therapy in patients with cancer and the achievement of an INR ≥2 for ≥24 hours before parenteral anticoagulants are stopped.

Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy.

BACKGROUND Venous thromboembolism (VTE) often complicates the clinical course of cancer. The risk is further increased by chemotherapy, but the safety and efficacy of primary thromboprophylaxis in cancer patients treated with chemotherapy is uncertain. This is an update of a review first published in February 2012. OBJECTIVES To assess the efficacy and safety of primary thromboprophylaxis for VTE in ambulatory cancer patients receiving chemotherapy compared with placebo or no thromboprophylaxis. SEARCH METHODS For this update, the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2013), CENTRAL (2013, Issue 5), and clinical trials registries (up to June 2013). SELECTION CRITERIA Randomised controlled trials (RCTs) comparing any oral or parenteral anticoagulant or mechanical intervention to no intervention or placebo, or comparing two different anticoagulants. DATA COLLECTION AND ANALYSIS Data were extracted on methodological quality, patients, interventions, and outcomes including symptomatic VTE and major bleeding as the primary effectiveness and safety outcomes, respectively. MAIN RESULTS We identified 12 additional RCTs (6323 patients) in the updated search so that this update considered 21 trials with a total of 9861 patients, all evaluating pharmacological interventions and performed mainly in patients with advanced cancer. Overall, the risk of bias varied from low to high. One large trial of 3212 patients found a 64% (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.22 to 0.60) reduction of symptomatic VTE with the ultra-low molecular weight heparin (uLMWH) semuloparin relative to placebo, with no apparent difference in major bleeding (RR 1.05, 95% CI 0.55 to 2.00). LMWH, when compared with inactive control, significantly reduced the incidence of symptomatic VTE (RR 0.53, 95% CI 0.38 to 0.75; no heterogeneity, Tau(2) = 0%) with similar rates of major bleeding events (RR 1.30, 95% CI 0.75 to 2.23). In patients with multiple myeloma, LMWH was associated with a significant reduction in symptomatic VTE when compared with the vitamin K antagonist warfarin (RR 0.33, 95% CI 0.14 to 0.83), while the difference between LMWH and aspirin was not statistically significant (RR 0.51, 95% CI 0.22 to 1.17). No major bleeding was observed in the patients treated with LMWH or warfarin and in less than 1% of those treated with aspirin. Only one study evaluated unfractionated heparin against inactive control and found an incidence of major bleeding of 1% in both study groups while not reporting on VTE. When compared with placebo, warfarin was associated with a statistically insignificant reduction of symptomatic VTE (RR 0.15, 95% CI 0.02 to 1.20). Antithrombin, evaluated in one study involving paediatric patients, had no significant effect on VTE nor major bleeding when compared with inactive control. The new oral factor Xa inhibitor apixaban was evaluated in a phase-II dose finding study that suggested a promising low rate of major bleeding (2.1% versus 3.3%) and symptomatic VTE (1.1% versus 10%) in comparison with placebo. AUTHORS' CONCLUSIONS In this update, we confirmed that primary thromboprophylaxis with LMWH significantly reduced the incidence of symptomatic VTE in ambulatory cancer patients treated with chemotherapy. In addition, the uLMWH semuloparin significantly reduced the incidence of symptomatic VTE. However, the broad confidence intervals around the estimates for major bleeding suggest caution in the use of anticoagulation and mandate additional studies to determine the risk to benefit ratio of anticoagulants in this setting. Despite the encouraging results of this review, routine prophylaxis in ambulatory cancer patients cannot be recommended before safety issues are adequately addressed.

Thrombophlebitis of the temporal vein as an extracranial complication of acute bacterial rhinosinusitis

A 39-year-old white man presented with a swollen left upper eyelid secondary to progressive acute bacterial rhinosinusitis (ABRS). Physical examination found a 40% reduction in vision in the left eye and right-sided erythematous temporal swelling with tenderness to palpation. Computed tomography revealed the presence of an inflammatory lesion in the left orbit. Duplex ultrasonography demonstrated a thrombotic occlusion in the right superficial temporal vein (STV). For treatment of the complicated ARBS, the patient received intravenous antibiotics and underwent surgery. The STV thrombophlebitis was treated with low-molecular-weight heparin. Postoperatively, the patient recovered completely and his vision normalized; 10 days later, duplex ultrasonography showed a patent STV. The development of contralateral STV thrombophlebitis is conceivably facilitated by venous anastomoses of the scalp in the front of the head. As a result, embolic spread would be a possible complication of infectious ABRS foci communicating with intraorbital and pericranial veins. To the best of our knowledge, this is the first reported case of such a complication of ARBS in the literature.

Treatment for superficial infusion thrombophlebitis of the upper extremity.

BACKGROUND Although superficial thrombophlebitis of the upper extremity represents a frequent complication of intravenous catheters inserted into the peripheral veins of the forearm or hand, no consensus exists on the optimal management of this condition in clinical practice. OBJECTIVES To summarise the evidence from randomised clinical trials (RCTs) concerning the efficacy and safety of (topical, oral or parenteral) medical therapy of superficial thrombophlebitis of the upper extremity. SEARCH METHODS The Cochrane Vascular Group Trials Search Co-ordinator searched the Specialised Register (last searched April 2015) and the Cochrane Register of Studies (2015, Issue 3). Clinical trials registries were searched up to April 2015. SELECTION CRITERIA RCTs comparing any (topical, oral or parenteral) medical treatment to no intervention or placebo, or comparing two different medical interventions (e.g. a different variant scheme or regimen of the same intervention or a different pharmacological type of treatment). DATA COLLECTION AND ANALYSIS We extracted data on methodological quality, patient characteristics, interventions and outcomes, including improvement of signs and symptoms as the primary effectiveness outcome, and number of participants experiencing side effects of the study treatments as the primary safety outcome. MAIN RESULTS We identified 13 studies (917 participants). The evaluated treatment modalities consisted of a topical treatment (11 studies), an oral treatment (2 studies) and a parenteral treatment (2 studies). Seven studies used a placebo or no intervention control group, whereas all others also or solely compared active treatment groups. No study evaluated the effects of ice or the application of cold or hot bandages. Overall, the risk of bias in individual trials was moderate to high, although poor reporting hampered a full appreciation of the risk in most studies. The overall quality of the evidence for each of the outcomes varied from low to moderate mainly due to risk of bias and imprecision, with only single trials contributing to most comparisons. Data on primary outcomes improvement of signs and symptoms and side effects attributed to the study treatment could not be statistically pooled because of the between-study differences in comparisons, outcomes and type of instruments to measure outcomes.An array of topical treatments, such as heparinoid or diclofenac gels, improved pain compared to placebo or no intervention. Compared to placebo, oral non-steroidal anti-inflammatory drugs reduced signs and symptoms intensity. Safety issues were reported sparsely and were not available for some interventions, such as notoginseny creams, parenteral low-molecular-weight heparin or defibrotide. Although several trials reported on adverse events with topical heparinoid creams, Essaven gel or phlebolan versus control, the trials were underpowered to adequately measure any differences between treatment modalities. Where reported, adverse events with topical treatments consisted mainly of local allergic reactions. Only one study of 15 participants assessed thrombus extension and symptomatic venous thromboembolism with either oral non-steroidal anti-inflammatory drugs or low-molecular-weight heparin, and it reported no cases of either. No study reported on the development of suppurative phlebitis, catheter-related bloodstream infections or quality of life. AUTHORS' CONCLUSIONS The evidence about the treatment of acute infusion superficial thrombophlebitis is limited and of low quality. Data appear too preliminary to assess the effectiveness and safety of topical treatments, systemic anticoagulation or oral non-steroidal anti-inflammatory drugs.

Primary prophylaxis for venous thromboembolism in patients undergoing cardiac or thoracic surgery.

BACKGROUND Cardiac and thoracic surgery are associated with an increased risk of venous thromboembolism (VTE). The safety and efficacy of primary thromboprophylaxis in patients undergoing these types of surgery is uncertain. OBJECTIVES To assess the effects of primary thromboprophylaxis on the incidence of symptomatic VTE and major bleeding in patients undergoing cardiac or thoracic surgery. SEARCH METHODS The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2014) and CENTRAL (2014, Issue 4). The authors searched the reference lists of relevant studies, conference proceedings, and clinical trial registries. SELECTION CRITERIA Randomised controlled trials (RCTs) and quasi-RCTs comparing any oral or parenteral anticoagulant or mechanical intervention to no intervention or placebo, or comparing two different anticoagulants. DATA COLLECTION AND ANALYSIS We extracted data on methodological quality, participant characteristics, interventions, and outcomes including symptomatic VTE and major bleeding as the primary effectiveness and safety outcomes, respectively. MAIN RESULTS We identified 12 RCTs and one quasi-RCT (6923 participants), six for cardiac surgery (3359 participants) and seven for thoracic surgery (3564 participants). No study evaluated fondaparinux, the new oral direct thrombin, direct factor Xa inhibitors, or caval filters. All studies had major study design flaws and most lacked a placebo or no treatment control group. We typically graded the quality of the overall body of evidence for the various outcomes and comparisons as low, due to imprecise estimates of effect and risk of bias. We could not pool data because of the different comparisons and the lack of data. In cardiac surgery, 71 symptomatic VTEs occurred in 3040 participants from four studies. In a study of 2551 participants, representing 85% of the review population in cardiac surgery, the combination of unfractionated heparin with pneumatic compression stockings was associated with a 61% reduction of symptomatic VTE compared to unfractionated heparin alone (1.5% versus 4.0%; risk ratio (RR) 0.39; 95% confidence interval (CI) 0.23 to 0.64). Major bleeding was only reported in one study, which found a higher incidence with vitamin K antagonists compared to platelet inhibitors (11.3% versus 1.6%, RR 7.06; 95% CI 1.64 to 30.40). In thoracic surgery, 15 symptomatic VTEs occurred in 2890 participants from six studies. In the largest study evaluating unfractionated heparin versus an inactive control the rates of symptomatic VTE were 0.7% versus 0%, respectively, giving a RR of 6.71 (95% CI 0.40 to 112.65). There was insufficient evidence to determine if there was a difference in the risk of major bleeding from two studies evaluating fixed-dose versus weight-adjusted low molecular weight heparin (2.7% versus 8.1%, RR 0.33; 95% CI 0.07 to 1.60) and unfractionated heparin versus low molecular weight heparin (6% and 4%, RR 1.50; 95% CI 0.26 to 8.60). AUTHORS' CONCLUSIONS The evidence regarding the efficacy and safety of thromboprophylaxis in cardiac and thoracic surgery is limited. Data for important outcomes such as pulmonary embolism or major bleeding were often lacking. Given the uncertainties around the benefit-to-risk balance, no conclusions can be drawn and a case-by-case risk evaluation of VTE and bleeding remains preferable.

Anticoagulation Management Practices and Outcomes in Elderly Patients with Acute Venous Thromboembolism: A Clinical Research Study.

Whether anticoagulation management practices are associated with improved outcomes in elderly patients with acute venous thromboembolism (VTE) is uncertain. Thus, we aimed to examine whether practices recommended by the American College of Chest Physicians guidelines are associated with outcomes in elderly patients with VTE. We studied 991 patients aged ≥65 years with acute VTE in a Swiss prospective multicenter cohort study and assessed the adherence to four management practices: parenteral anticoagulation ≥5 days, INR ≥2.0 for ≥24 hours before stopping parenteral anticoagulation, early start with vitamin K antagonists (VKA) ≤24 hours of VTE diagnosis, and the use of low-molecular-weight heparin (LMWH) or fondaparinux. The outcomes were all-cause mortality, VTE recurrence, and major bleeding at 6 months, and the length of hospital stay (LOS). We used Cox regression and lognormal survival models, adjusting for patient characteristics. Overall, 9% of patients died, 3% had VTE recurrence, and 7% major bleeding. Early start with VKA was associated with a lower risk of major bleeding (adjusted hazard ratio 0.37, 95% CI 0.20-0.71). Early start with VKA (adjusted time ratio [TR] 0.77, 95% CI 0.69-0.86) and use of LMWH/fondaparinux (adjusted TR 0.87, 95% CI 0.78-0.97) were associated with a shorter LOS. An INR ≥2.0 for ≥24 hours before stopping parenteral anticoagulants was associated with a longer LOS (adjusted TR 1.2, 95% CI 1.08-1.33). In elderly patients with VTE, the adherence to recommended anticoagulation management practices showed mixed results. In conclusion, only early start with VKA and use of parenteral LMWH/fondaparinux were associated with better outcomes.

Conjugation of an antibody to cross-linked fibrin for targeted delivery of anti-restenotic drugs

There is an urgent need to treat restenosis, a major complication of the treatment of arteries blocked by atherosclerotic plaque, using local delivery techniques. We observed that cross-linked fibrin (XLF) is deposited at the site of surgical injury of arteries. An antibody to XLF, conjugated to anti-restenotic agents, should deliver the drugs directly and only to the site of injury. An anti-XLF antibody (H93.7C.1D2/48; 1D2) was conjugated to heparin (using N-succinimidyl 3-(2-pyridyldithio)-propionate), low molecular weight heparin (LMWH) (adipic acid dihydrazide) and rapamycin (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide), and the conjugates purified and tested for activity before use in vivo. Rabbits had their right carotid arteries de-endothelialised and then given a bolus of 1D2-heparin, 1D2-LMWH or 1D2-rapamycin conjugate or controls of saline, heparin, LMWH, rapamycin or 1D2 (+/-heparin bolus) and sacrificed after 2 or 4 weeks (12 groups, n=6/group). Rabbits given any of the conjugates had minimal neointimal development in injured arteries, with up to 59% fewer neointimal cells than those given control drugs. Rabbits given 1D2-heparin or 1D2-LMWH had an increased or insignificant reduction in luminal area, with positive remodelling, while the medial and total arterial areas of rabbits given 1D2-rapamycin were not affected by injury. Arteries exposed to 1D2-heparin or 1D2-rapamycin had more endothelial cells than rabbits given control drugs. Thus, XLF-antibodies can site-deliver anti-restenotic agents to injured areas of the artery wall, where the conjugates can influence remodelling, re-endothelialisation and neointimal cell density, with reduced neointimal formation. (C) 2004 Elsevier B.V. All rights reserved.