Idarucizumab

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 )

PRAXBIND is a sterile, preservative-free, colorless to slightly yellow, clear to slightly opalescent solution available as: Injection: 2.5 g/50 mL solution in a single-dose vial. Injection: 2.5 g/50 mL solution in a single-dose vial ( 3 )

None. None ( 4 )

Thromboembolic Risk: Reversing dabigatran therapy exposes patients to the thrombotic risk of their underlying disease. Resume anticoagulant therapy as soon as medically appropriate. ( 2.4 , 5.1 ) Re-elevation of Coagulation Parameters: In patients with elevated coagulation parameters and reappearance of clinically relevant bleeding or requiring a second emergency surgery/urgent procedure, an additional 5 g dose of PRAXBIND may be considered. ( 5.2 ) Hypersensitivity reactions: Discontinue administration and evaluate. ( 5.3 ) Risks of Serious Adverse Reactions in Patients with Hereditary Fructose Intolerance due to Sorbitol Excipient: Patients with hereditary fructose intolerance may be at risk of adverse reactions. ( 5.4 )

5.1 Thromboembolic Risk 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 [see Dosage and Administration (2.4) ].

5.2 Re-elevation of Coagulation Parameters In a limited number of patients in the clinical program, between 12 and 24 hours after administration of 5 g idarucizumab, elevated coagulation parameters (e.g., activated partial thromboplastin time (aPTT) or ecarin clotting time (ECT)) have been observed [see Dosage and Administration (2.1) ]. If reappearance of clinically relevant bleeding together with elevated coagulation parameters is observed after administration of 5 g PRAXBIND, administration of an additional 5 g dose of PRAXBIND may be considered. Similarly, patients who require a second emergency surgery/urgent procedure and have elevated coagulation parameters may receive an additional 5 g dose of PRAXBIND. The safety and effectiveness of repeat treatment with PRAXBIND have not been established [see Clinical Pharmacology (12.2) ] .

5.3 Hypersensitivity Reactions There is insufficient clinical experience with PRAXBIND in patients to evaluate risk of hypersensitivity to idarucizumab. In clinical studies adverse events possibly indicative of hypersensitivity reactions where a possible relationship could not be excluded were reported [see Adverse Reactions (6.1) ] . The risk of using PRAXBIND in patients with known hypersensitivity (e.g., anaphylactoid reaction) to idarucizumab or to any of the excipients needs to be weighed cautiously against the potential benefit of such an emergency treatment. If an anaphylactic reaction or other serious allergic reaction occurs, immediately discontinue administration of PRAXBIND and institute appropriate treatment.

5.4 Risks of Serious Adverse Reactions in Patients with Hereditary Fructose Intolerance due to Sorbitol Excipient In patients with the condition of hereditary fructose intolerance who have received parenteral administration of sorbitol, serious adverse reactions, including fatal reactions, have been reported. Reactions have included hypoglycemia, hypophosphatemia, metabolic acidosis, increase in uric acid, acute liver failure with breakdown of excretory and synthetic function. The recommended dose of PRAXBIND contains 4 g sorbitol as an excipient. When prescribing PRAXBIND to patients with hereditary fructose intolerance, consider the combined daily metabolic load of sorbitol/fructose from all sources, including PRAXBIND and other drugs containing sorbitol. The minimum amount of sorbitol at which serious adverse reactions may occur in these patients is not known.

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.

8.1 Pregnancy Risk Summary There are no available data on PRAXBIND use in pregnant women to inform a drug-associated risk of major birth defects and miscarriage. Animal reproductive and development studies have not been conducted with idarucizumab. It is also not known whether PRAXBIND can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. PRAXBIND should be given to a pregnant woman only if clearly needed. The background risk of major birth defects and miscarriage for the indicated population is unknown. Adverse outcomes in pregnancy occur regardless of the health of the mother or the use of medications. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

8.2 Lactation Risk Summary There are no data on the effects of PRAXBIND on the breastfed child or on milk production. It is not known whether idarucizumab is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when PRAXBIND is administered to a nursing woman. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for PRAXBIND and any potential adverse effects on the breastfed child from PRAXBIND or from the underlying maternal condition.

8.4 Pediatric Use Safety and effectiveness have not been established in pediatric patients.

8.5 Geriatric Use A total of 454 (90%) patients treated with idarucizumab in the case series trial were 65 years of age and older, and 318 (63%) were 75 years of age and older. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

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.