Idarucizumab

12.1 Mechanism of Action Idarucizumab is a specific reversal agent for dabigatran. It is a humanized monoclonal antibody fragment (Fab) that binds to dabigatran and its acylglucuronide metabolites with higher affinity than the binding affinity of dabigatran to thrombin, neutralizing their anticoagulant effect.

1 INDICATIONS AND USAGE PRAXBIND is indicated in patients treated with Pradaxa when reversal of the anticoagulant effects of dabigatran is needed: For emergency surgery/urgent procedures In life-threatening or uncontrolled bleeding PRAXBIND is a humanized monoclonal antibody fragment (Fab) indicated in patients treated with Pradaxa ® when reversal of the anticoagulant effects of dabigatran is needed: For emergency surgery/urgent procedures In life-threatening or uncontrolled bleeding ( 1 )

2 DOSAGE AND ADMINISTRATION For intravenous use only. The recommended dose of PRAXBIND is 5 g, provided as two separate vials each containing 2.5 g/50 mL idarucizumab. ( 2.1 ) There is limited data to support administration of an additional 5 g of PRAXBIND. ( 2.1 ) 2.1 Recommended Dose The recommended dose of PRAXBIND is 5 g, provided as two separate vials each containing 2.5 g/50 mL idarucizumab (see Figure 1 ). Both vials are packaged together in one carton. For intravenous use only. There is limited data to support administration of an additional 5 g of PRAXBIND [see Warnings and Precautions (5.2) ]. 2.2 Preparation Remove both vials (each containing 2.5 g/50 mL idarucizumab) from carton. Ensure aseptic handling when preparing the infusion. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Once solution has been removed from the vial, administration should begin promptly. The solution in vials may be stored at room temperature, 25°C (77°F), but must be used within 6 hours [see How Supplied/Storage and Handling (16.2) ] . 2.3 Administration Do not mix with other medicinal products. Use aseptic technique when administering PRAXBIND. Intravenously administer the dose of 5 g (2 vials, each contains 2.5 g) as Two consecutive infusions (see Figure 2 ) or Bolus injection by injecting both vials consecutively one after another via syringe (see Figure 3 ). A pre-existing intravenous line may be used for administration of PRAXBIND. The line must be flushed with sterile 0.9% Sodium Chloride Injection, USP solution prior to infusion. No other infusion should be administered in parallel via the same intravenous access. PRAXBIND treatment can be used in conjunction with standard supportive measures, which should be considered as medically appropriate [see Clinical Pharmacology (12.2) ]. Figure 1 Recommended dose of PRAXBIND provided as two vials. Figure 2 Two consecutive infusions by hanging vials. Figure 3 Inject both vials consecutively via syringe. Figure 1 Figure 2 Figure 3 2.4 Restarting Antithrombotic Therapy Patients being treated with dabigatran therapy have underlying disease states that predispose them to thromboembolic events. Reversing dabigatran therapy exposes patients to the thrombotic risk of their underlying disease. To reduce this risk, resumption of anticoagulant therapy should be considered as soon as medically appropriate. Idarucizumab is a specific reversal agent for dabigatran, with no impact on the effect of other anticoagulant or antithrombotic therapies. Pradaxa treatment can be initiated 24 hours after administration of PRAXBIND [see Clinical Pharmacology (12.2) ].

6 ADVERSE REACTIONS The following serious adverse reactions are described in more detail elsewhere in the labeling: Thromboembolic Risk [see Warnings and Precautions (5.1) ] Hypersensitivity Reactions [see Warnings and Precautions (5.3) ] Risks of Serious Adverse Reactions in Patients with Hereditary Fructose Intolerance due to Sorbitol Excipient [see Warnings and Precautions (5.4) ] In healthy volunteers, the most frequently reported adverse reactions in ≥5% of subjects treated with idarucizumab was headache. ( 6.1 ) In patients, the most frequently reported adverse reactions in ≥5% of patients treated with idarucizumab were constipation and nausea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Boehringer Ingelheim Pharmaceuticals, Inc. at 1-800-542-6257 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. In three healthy volunteer clinical trials, 224 subjects were treated with idarucizumab. In these trials, during the treatment period, the overall frequency of adverse events was similar between idarucizumab-treated subjects (55/224, 25%) and placebo-treated subjects (26/105, 25%). Among those subjects treated with idarucizumab, adverse reactions reported in ≥5% of subjects was headache (12/224, 5%). In the RE-VERSE-AD ® (RE-VERSal Effects of idarucizumab on Active Dabigatran) trial, a total of 503 dabigatran-treated patients were administered idarucizumab either because they required an emergency surgery or urgent procedure, or because they presented with life-threatening or uncontrolled bleeding [see Clinical Studies (14) ]. The adverse reactions reported in ≥5% of patients were constipation (33/503, 7%) and nausea (23/503, 5%). Of the 503 dabigatran-treated patients in the entire study period, 101 patients died, 19 within the first day after idarucizumab dosing; each of these deaths could be attributed either as a complication of the index event or associated with co-morbidities. Thromboembolic Events In the RE-VERSE-AD trial, 33 of 503 patients reported thrombotic events, 11 patients within 5 days after treatment with idarucizumab and 22 patients 6 days or more after treatment with idarucizumab. Most of these patients were not on antithrombotic therapy at the time of the event, and in each of these cases, the thrombotic event could be attributed to the underlying medical condition of the patient [see Warnings and Precautions (5.1) ]. Hypersensitivity Pyrexia, bronchospasm, hyperventilation, rash, and pruritus have been reported in clinical trials with idarucizumab [see Warnings and Precautions (5.3) ]. 6.2 Immunogenicity As with all proteins there is a potential for immunogenicity with idarucizumab. Detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant medications and underlying disease. For these reasons, comparison of the incidence of antibodies to idarucizumab in the studies described below with the incidence of antibodies in other studies or to other products may be misleading. Using an electro-chemiluminescence (ECL) based assay, plasma samples from 283 subjects (224 treated with idarucizumab) in phase I trials and 501 patients were tested for antibodies cross-reacting with idarucizumab. Pre-existing antibodies with cross-reactivity to idarucizumab were detected in approximately 12% (33/283) of the subjects and 4% (19/501) of patients. The majority of pre-existing antibodies were shown to have low titers. No impact on the pharmacokinetics or the reversal effect of idarucizumab or hypersensitivity reactions were observed. Treatment-emergent possibly persisting anti-idarucizumab antibodies with low titers were observed in 4% (10/224) of the subjects and 2% (8/501) of patients treated with idarucizumab. Nine patients were re-dosed with idarucizumab. All nine patients were re-dosed within 6 days after the first idarucizumab dose. None of these patients re-dosed with idarucizumab tested positive for anti-idarucizumab antibodies. The epitope specificity of antibodies to idarucizumab was characterized using probe molecules. For pre-existing antibodies in patients, 95% (18/19) had specificity for the C-terminus, a region of idarucizumab to which dabigatran does not bind. For treatment emergent antibodies in patients, 67% (6/9) had specificity for the C-terminus, 22% (2/9) had specificity for the variable region, and 11% (1/9) had mixed specificity.