TAKHZYRO: Uses, Dosage & Side Effects
A plasma kallikrein inhibitor monoclonal antibody for the routine prevention of hereditary angioedema (HAE) attacks in patients aged 2 years and older
TAKHZYRO (lanadelumab) is a prescription monoclonal antibody used for the routine prevention of hereditary angioedema (HAE) attacks in patients aged 2 years and older. It works by targeting and inhibiting plasma kallikrein, an enzyme that drives the overproduction of bradykinin responsible for the characteristic swelling episodes in HAE. TAKHZYRO is administered as a subcutaneous injection every two to four weeks, depending on patient weight and clinical response. The pivotal HELP Study demonstrated that TAKHZYRO reduced HAE attack rates by up to 87% compared to placebo. It can be self-administered at home after appropriate training, offering patients with this rare genetic condition greater independence and significantly improved quality of life.
Quick Facts: TAKHZYRO
Key Takeaways
- TAKHZYRO (lanadelumab) is a monoclonal antibody that prevents hereditary angioedema (HAE) attacks by blocking plasma kallikrein, reducing bradykinin-mediated swelling.
- Approved for patients aged 2 years and older, it is given as a subcutaneous injection every 2 to 4 weeks depending on body weight and clinical response.
- The HELP Study showed TAKHZYRO reduced HAE attack rates by up to 87% versus placebo, with many patients becoming attack-free during treatment.
- The most common side effects are injection site reactions (pain, redness, bruising); serious allergic reactions are rare but possible.
- Patients aged 12 and older can self-inject at home after training, while younger children require administration by a healthcare professional or caregiver.
What Is TAKHZYRO and What Is It Used For?
TAKHZYRO contains the active substance lanadelumab, a fully human monoclonal antibody of the IgG1 kappa subclass. It was specifically designed to target and inhibit plasma kallikrein, a key enzyme in the biochemical cascade that leads to HAE symptoms. TAKHZYRO received its first regulatory approval from the FDA in August 2018, followed by EMA approval in November 2018, marking a significant advancement in the long-term prophylactic management of HAE.
Hereditary angioedema is a rare autosomal dominant genetic disorder that affects an estimated 1 in 50,000 people worldwide. The condition is characterized by recurrent episodes of severe swelling (angioedema) that can affect multiple parts of the body, including the hands, feet, face, eyelids, lips, tongue, larynx (throat), gastrointestinal tract, and genitalia. Laryngeal attacks are particularly dangerous, as they can cause life-threatening airway obstruction.
Understanding Hereditary Angioedema (HAE)
HAE is caused by mutations in the SERPING1 gene, which encodes C1-inhibitor (C1-INH), a serine protease inhibitor. In the most common forms of HAE, there is either insufficient production of C1-INH (Type I, accounting for approximately 85% of cases) or production of a dysfunctional form of C1-INH (Type II, approximately 15% of cases). C1-INH normally regulates several proteolytic cascades in the body, including the contact activation (kallikrein-kinin) system, the complement system, and the coagulation and fibrinolytic cascades.
When C1-INH is deficient or dysfunctional, plasma kallikrein activity becomes uncontrolled. Plasma kallikrein cleaves high-molecular-weight kininogen (HMWK) to produce bradykinin, a potent vasoactive peptide. Excessive bradykinin binds to bradykinin B2 receptors on endothelial cells, increasing vascular permeability and causing the tissue swelling characteristic of HAE. Attacks are unpredictable, can be debilitating, and significantly impair quality of life.
How TAKHZYRO Works
TAKHZYRO is a monoclonal antibody that specifically binds to active plasma kallikrein and blocks its proteolytic activity. By inhibiting plasma kallikrein, lanadelumab prevents the excessive cleavage of HMWK and the resulting overproduction of bradykinin. This targeted mechanism addresses the root biochemical cause of HAE attacks, rather than treating symptoms after they occur.
In clinical studies, TAKHZYRO demonstrated sustained suppression of plasma kallikrein activity over the dosing interval. This consistent pharmacological effect translates into a significant reduction in the frequency, severity, and duration of HAE attacks. Unlike on-demand treatments that are used to treat acute attacks after they begin, TAKHZYRO is used prophylactically to prevent attacks from occurring in the first place.
TAKHZYRO is intended for preventive (prophylactic) use only. It is not indicated for the treatment of acute HAE attacks. Patients should continue to have access to rescue medication for breakthrough attacks that may still occur during prophylactic treatment.
What Should You Know Before Taking TAKHZYRO?
Before starting treatment with TAKHZYRO, it is essential to have a thorough discussion with your healthcare provider about your medical history, current medications, and any known allergies. While TAKHZYRO has demonstrated a favorable safety profile in clinical trials, certain precautions and considerations apply to ensure safe and effective use of this medication.
Contraindications
TAKHZYRO must not be used if you have a known hypersensitivity (allergy) to lanadelumab or to any of the other ingredients in the formulation. The excipients include disodium phosphate dihydrate, citric acid monohydrate, histidine, sodium chloride, polysorbate 80, and water for injections. If you have experienced a previous allergic reaction to any monoclonal antibody therapy, discuss this with your doctor before starting TAKHZYRO.
Warnings and Precautions
Speak with your doctor, pharmacist, or nurse before using TAKHZYRO. Hypersensitivity reactions, including anaphylaxis, have been reported in patients treated with TAKHZYRO. If you experience symptoms such as rash, chest tightness, wheezing, difficulty breathing, or a rapid heartbeat after an injection, seek immediate medical attention. Your healthcare provider should be prepared to manage potential hypersensitivity reactions.
TAKHZYRO can interfere with certain blood coagulation tests, particularly the activated partial thromboplastin time (aPTT). This interference may lead to falsely prolonged aPTT results, which do not reflect an actual coagulation abnormality. Inform your doctor that you are using TAKHZYRO before undergoing any blood coagulation tests. Other coagulation assays that depend on aPTT, such as the one-stage factor VIII activity assay, may also be affected.
It is strongly recommended that you record the product name and batch number each time you receive a dose of TAKHZYRO. This allows you to keep track of the batches used, which can be important for traceability and pharmacovigilance purposes.
Use in Children
TAKHZYRO is approved for use in patients aged 2 years and older. The dosing regimen for children varies based on body weight. TAKHZYRO has not been studied in children under 2 years of age, and its use in this age group is not recommended. For children aged 2 to under 12 years, administration should be performed by a healthcare professional or trained caregiver. Adolescents aged 12 and older may self-administer after receiving proper training from their healthcare provider.
Pregnancy and Breastfeeding
There is limited information regarding the safety of TAKHZYRO during pregnancy and breastfeeding. As a precautionary measure, it is recommended to avoid using lanadelumab during pregnancy and breastfeeding unless the potential benefit to the mother justifies the potential risk to the fetus or nursing infant. Monoclonal antibodies are known to cross the placental barrier, particularly during the third trimester, and may also be present in breast milk. If you are pregnant, suspect you may be pregnant, or are planning a pregnancy, consult your doctor before starting or continuing TAKHZYRO.
Driving and Operating Machinery
TAKHZYRO has no or negligible effect on the ability to drive and operate machinery. No studies on the effects on driving and use of machines have been performed. However, some patients may experience dizziness as a side effect, so caution is advisable until you know how TAKHZYRO affects you personally.
Sodium Content
TAKHZYRO contains less than 1 mmol (23 mg) sodium per vial, meaning it is essentially sodium-free. This is relevant for patients on a controlled sodium diet.
How Does TAKHZYRO Interact with Other Drugs?
One of the advantages of TAKHZYRO is its favorable drug interaction profile. Because lanadelumab is a monoclonal antibody (a large protein molecule), it is catabolized through normal proteolytic pathways rather than being metabolized by hepatic cytochrome P450 (CYP) enzymes. This means TAKHZYRO does not compete with or affect the metabolism of other medications processed through the CYP enzyme system, which is the mechanism behind most traditional drug-drug interactions.
No formal drug-drug interaction studies have been conducted with TAKHZYRO. However, based on its pharmacological properties and mechanism of catabolism, no clinically relevant interactions are expected. In clinical trials, patients continued their existing medications without evidence of interaction.
| Interaction Type | Substances | Clinical Significance |
|---|---|---|
| Laboratory Interference | aPTT-based coagulation assays, Factor VIII one-stage assay | May cause falsely prolonged aPTT results; inform laboratory staff |
| CYP Enzyme Interactions | None identified | Not metabolized by CYP enzymes; no expected interactions |
| Other HAE Therapies | C1-inhibitor concentrates, icatibant, ecallantide | Can be used alongside acute treatment; no interaction data suggest concern |
| Oral Contraceptives | Combined oral contraceptives, progestin-only pills | No interaction expected; note that exogenous estrogens may trigger HAE attacks independently |
| ACE Inhibitors | Enalapril, lisinopril, ramipril, etc. | ACE inhibitors should generally be avoided in HAE patients as they can increase bradykinin levels independently |
While TAKHZYRO itself does not have clinically significant drug interactions, patients with HAE should be aware that certain medications can exacerbate their underlying condition. Angiotensin-converting enzyme (ACE) inhibitors are generally contraindicated in HAE because they inhibit the degradation of bradykinin, potentially triggering or worsening angioedema episodes. Similarly, estrogen-containing medications (including oral contraceptives and hormone replacement therapy) may increase the frequency and severity of HAE attacks in some patients, although this is an effect on the disease rather than an interaction with TAKHZYRO.
Always inform your healthcare provider about all medications you are taking, including prescription drugs, over-the-counter medications, herbal supplements, and vitamins. While TAKHZYRO is unlikely to interact with these substances, maintaining a comprehensive medication list helps your healthcare team provide the best possible care.
What Is the Correct Dosage of TAKHZYRO?
TAKHZYRO treatment should be initiated and managed under the supervision of a physician experienced in the treatment of HAE. The dosage depends on the patient's age, body weight, and clinical response. TAKHZYRO is supplied as a ready-to-use solution in single-use vials and is administered as a subcutaneous injection into the fatty tissue of the abdomen, thigh, or upper arm. The injection site should be rotated with each dose.
Adults and Adolescents (12 Years and Older)
Standard Dosing
The recommended starting dose is 300 mg lanadelumab every 2 weeks (every other week). For patients who achieve sustained attack-free status over a prolonged period, the dosing interval may be extended to 300 mg every 4 weeks, particularly in patients with lower body weight. This dose reduction should be determined by the treating physician based on individual clinical response.
Patients Under 40 kg
For patients weighing less than 40 kg, a starting dose of 150 mg every 2 weeks may be considered. If well controlled, the dose may be reduced to 150 mg every 4 weeks.
Children (2 to Under 12 Years)
The dosing for pediatric patients aged 2 to under 12 years is based on body weight. The following table outlines the weight-based dosing recommendations:
| Body Weight | Recommended Starting Dose | Dose Adjustment |
|---|---|---|
| 10 to less than 20 kg | 150 mg every 4 weeks | May increase to 150 mg every 3 weeks if attack control is insufficient |
| 20 to less than 40 kg | 150 mg every 2 weeks | May decrease to 150 mg every 4 weeks if stably attack-free |
| 40 kg or more | 300 mg every 2 weeks | May decrease to 300 mg every 4 weeks if stably attack-free |
For children weighing 20 to less than 40 kg who have been attack-free for a prolonged period, the prescribing physician may choose to maintain the same dose when the child reaches 12 years of age rather than automatically switching to the adult dosing regimen.
Administration Method
TAKHZYRO is administered as a subcutaneous injection. Each single-use vial contains 300 mg of lanadelumab in 2 mL of solution. The injection kit includes a 3 mL syringe, an 18-gauge blunt needle for drawing up the solution from the vial, and a 27-gauge sharp needle for the injection. Patients aged 12 and older (or their caregivers) may self-administer after receiving proper training from a healthcare professional. For children aged 2 to under 12 years, injections should be given by a healthcare professional or trained caregiver.
Before injection, the vial should be removed from the refrigerator 15 minutes prior to use to allow it to reach room temperature (15 to 25 degrees Celsius). The solution should be clear, colorless to slightly yellow, and free of visible particles. Do not use the solution if it appears discolored or contains particulate matter. Do not shake the vial, as this may cause foaming.
Missed Dose
If you miss a dose, administer the injection as soon as possible. To maintain proper dosing intervals, the next scheduled dose may need to be adjusted to ensure minimum time between doses:
- Every-2-week regimen: at least 10 days between doses
- Every-3-week regimen: at least 17 days between doses
- Every-4-week regimen: at least 24 days between doses
If you are unsure when to administer your next dose after a missed injection, contact your healthcare provider for guidance.
Overdose
There is limited experience with overdose of TAKHZYRO. In clinical trials, doses up to 400 mg subcutaneously were administered without dose-limiting toxicities. In the event of an accidental overdose, contact your healthcare provider, pharmacist, or local poison control center. Treatment should be supportive, with monitoring for any signs or symptoms of adverse reactions, and appropriate symptomatic treatment should be initiated as necessary.
It is important to continue your TAKHZYRO injections as directed by your doctor, even if you feel well and have not experienced attacks for some time. Discontinuation of prophylactic therapy may lead to a return of HAE attacks. Always consult your healthcare provider before making any changes to your treatment regimen.
What Are the Side Effects of TAKHZYRO?
Like all medicines, TAKHZYRO can cause side effects, although not everyone experiences them. The side effects observed in clinical trials were generally mild to moderate in severity and manageable. The safety profile of TAKHZYRO has been established through multiple clinical studies, including the pivotal HELP Study (a Phase 3, randomized, double-blind, placebo-controlled trial) and subsequent long-term extension studies with follow-up exceeding 3.5 years in some patients.
If you experience signs of a serious allergic reaction (anaphylaxis) such as widespread rash, tightness in the chest, wheezing, difficulty breathing, or a rapid heartbeat after receiving TAKHZYRO, contact your healthcare provider or emergency services immediately.
Very Common
May affect more than 1 in 10 patients
- Injection site reactions — including pain, redness (erythema), bruising, discomfort, swelling, bleeding, itching (pruritus), induration (hardening), tingling (paresthesia), warmth, and rash at the injection site
Common
May affect up to 1 in 10 patients
- Hypersensitivity reactions — including itching (pruritus), discomfort, and tingling of the tongue
- Dizziness or lightheadedness
- Urticaria (raised, itchy skin rash / hives)
- Myalgia (muscle pain)
- Elevated liver transaminases (changes in blood tests indicating liver enzyme elevations)
Rare / Post-Marketing
Reported in post-marketing surveillance
- Anaphylaxis or severe systemic hypersensitivity reactions (seek immediate medical attention)
Injection Site Reactions in Detail
Injection site reactions (ISRs) are the most frequently reported side effect of TAKHZYRO and are typical of subcutaneously administered biological medicines. In the HELP Study, ISRs were reported in approximately 52% of patients receiving lanadelumab compared to 34% in the placebo group. The vast majority of these reactions were mild in severity (Grade 1), with a smaller proportion being moderate (Grade 2). No severe ISRs were reported in clinical trials. ISRs typically resolved within a few hours to days without intervention. The frequency of ISRs tends to decrease over time with continued treatment.
Long-Term Safety
Long-term safety data from the HELP Study open-label extension (OLE) have been reassuring, with no new safety signals identified in patients treated for more than 3.5 years. The overall safety profile remained consistent with that observed in the pivotal trial, and no increased incidence of adverse events was noted with prolonged treatment. Anti-drug antibodies (ADAs) were detected in a small percentage of patients but did not appear to affect the efficacy or safety profile of lanadelumab.
Reporting Side Effects
Reporting suspected side effects after a medicine has been authorized is important for ongoing safety monitoring. It allows regulators and healthcare systems to continuously monitor the benefit-risk balance of the medication. You can report side effects to your national pharmacovigilance authority or through your healthcare provider.
How Should You Store TAKHZYRO?
Proper storage of TAKHZYRO is essential to maintain the stability and effectiveness of the medication. As a biological product (monoclonal antibody), lanadelumab is sensitive to temperature extremes and light exposure.
- Refrigeration: Store in a refrigerator at 2°C to 8°C (36°F to 46°F). This is the primary recommended storage condition.
- Do not freeze: Freezing can damage the protein structure of the monoclonal antibody and render the medication ineffective. If accidentally frozen, do not use the product.
- Light protection: Keep the vial in the outer carton to protect from light until ready for use.
- Room temperature storage: Vials may be stored at a temperature below 25°C (77°F) for a single period of up to 14 days, but must not exceed the printed expiration date. Do not return the vial to the refrigerator after room temperature storage.
- Visual inspection: Before use, check that the solution is clear, colorless to slightly yellow, and free of particles. Do not use if the solution appears cloudy, discolored, or contains visible particles.
- Keep out of reach of children: Store all medications where children cannot see or access them.
- Expiration date: Do not use TAKHZYRO after the expiration date (EXP) printed on the vial label and carton. The expiration date refers to the last day of that month.
Each TAKHZYRO vial is for single use only. Any unused product or waste material should be disposed of in accordance with local regulations. Do not dispose of medicines through wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required, as these measures help protect the environment.
What Does TAKHZYRO Contain?
Understanding the composition of TAKHZYRO is important for patients who may have allergies or sensitivities to specific excipients. The formulation has been designed to maintain the stability and bioavailability of lanadelumab when administered subcutaneously.
Active Ingredient
The active substance is lanadelumab. Each single-use vial contains 2 mL of solution with 300 mg of lanadelumab (150 mg/mL). Lanadelumab is a fully human immunoglobulin G1 kappa (IgG1κ) monoclonal antibody produced by recombinant DNA technology in Chinese hamster ovary (CHO) cells.
Inactive Ingredients (Excipients)
- Disodium phosphate dihydrate — buffering agent to maintain pH stability
- Citric acid monohydrate — buffering agent
- Histidine — amino acid buffer to stabilize the antibody structure
- Sodium chloride — tonicity agent to ensure the solution is isotonic
- Polysorbate 80 — surfactant to prevent aggregation and adsorption of the antibody
- Water for injections — solvent
Appearance and Packaging
TAKHZYRO is supplied as a clear, colorless to slightly yellow solution for injection in a glass vial. It is available in single-use packs containing one vial and in multi-packs containing 2 or 6 cartons, each with one vial. Not all pack sizes may be marketed in every country.
Each package also includes the following injection accessories:
- One empty 3 mL syringe
- One 18-gauge blunt-tip needle for withdrawing the solution from the vial
- One 27-gauge (13 mm) sharp-tip needle for subcutaneous injection
The marketing authorization holder is Takeda Pharmaceuticals International AG Ireland Branch, Dublin, Ireland. TAKHZYRO is marketed globally by Takeda, a global biopharmaceutical company with a strong focus on rare diseases, immunology, and gastroenterology.
Frequently Asked Questions About TAKHZYRO
TAKHZYRO (lanadelumab) is a prescription medication used for the routine prevention of hereditary angioedema (HAE) attacks in patients aged 2 years and older. HAE is a rare genetic condition that causes recurrent episodes of severe swelling in the hands, feet, face, airways, abdomen, and genitalia. TAKHZYRO works by blocking plasma kallikrein, an enzyme that triggers excessive bradykinin production responsible for HAE symptoms. It is not used to treat acute HAE attacks.
TAKHZYRO is given as a subcutaneous (under the skin) injection. It can be self-administered at home by patients aged 12 and older (or by a caregiver) after training from a healthcare professional. For children aged 2 to under 12 years, injections should be given by a healthcare professional or trained caregiver. The recommended starting dose for adults and adolescents is 300 mg every 2 weeks. Injection sites include the abdomen, thigh, or upper arm, and should be rotated with each dose.
The most common side effects of TAKHZYRO are injection site reactions, which may include pain, redness, bruising, discomfort, swelling, bleeding, itching, hardening of the skin, tingling, warmth, and rash. These reactions are generally mild and resolve on their own. Other common side effects include hypersensitivity reactions (itching, tingling of the tongue), dizziness, urticaria (hives), muscle pain, and changes in liver function blood tests. Serious allergic reactions (anaphylaxis) are rare.
There is limited data on the safety of TAKHZYRO during pregnancy and breastfeeding. As a precaution, it is recommended to avoid using lanadelumab during pregnancy and breastfeeding unless the potential benefit justifies the potential risk. Monoclonal antibodies are known to cross the placenta, particularly during the third trimester. If you are pregnant, planning to become pregnant, or breastfeeding, discuss the risks and benefits with your doctor before starting or continuing treatment.
In the pivotal HELP Study, TAKHZYRO 300 mg every 2 weeks reduced the mean rate of HAE attacks by 87% compared to placebo over the treatment period. Approximately 44% of patients in the every-2-week group were completely attack-free during the steady-state efficacy period (days 70 to 182). Long-term extension data showed sustained efficacy with continued treatment, with many patients maintaining very low or zero attack rates over several years of therapy.
No clinically significant drug interactions have been identified with TAKHZYRO. Because lanadelumab is a monoclonal antibody, it is not metabolized by cytochrome P450 enzymes and is not expected to interact with other medications through traditional drug-drug interaction mechanisms. However, TAKHZYRO can interfere with certain coagulation blood tests (aPTT), potentially causing falsely prolonged results. Always inform your doctor about all medications you are taking.
References
- European Medicines Agency (EMA). TAKHZYRO (lanadelumab) Summary of Product Characteristics. Last updated 2025. Available at: EMA EPAR — TAKHZYRO.
- U.S. Food and Drug Administration (FDA). TAKHZYRO Prescribing Information. Revised 2024. Available at: FDA Label — TAKHZYRO.
- Banerji A, Riedl MA, Bernstein JA, et al. Effect of Lanadelumab Compared With Placebo on Prevention of Hereditary Angioedema Attacks: A Randomized Clinical Trial (HELP Study). JAMA. 2018;320(20):2108-2121. doi:10.1001/jama.2018.16773.
- Maurer M, Magerl M, Betschel S, et al. The international WAO/EAACI guideline for the management of hereditary angioedema — The 2021 revision and update. World Allergy Organ J. 2022;15(3):100627. doi:10.1016/j.waojou.2022.100627.
- Riedl MA, Banerji A, Manning ME, et al. Treatment of hereditary angioedema with lanadelumab in the HELP Study open-label extension: Long-term safety and efficacy. J Allergy Clin Immunol Pract. 2022;10(5):1282-1291.
- Zuraw BL, Busse PJ, White M, et al. Nanofiltered C1 inhibitor concentrate for treatment of hereditary angioedema. N Engl J Med. 2010;363(6):513-522.
- Lumry WR, Settipane RA. Hereditary angioedema: Epidemiology and burden of disease. Allergy Asthma Proc. 2020;41(Suppl 1):S8-S13.
- World Health Organization (WHO). WHO Model List of Essential Medicines — 23rd List. Geneva: WHO; 2023.
Editorial Team
Medical Content
iMedic Medical Editorial Team — Specialists in Clinical Immunology and Pharmacology
Medical Review
iMedic Medical Review Board — Independent panel following EMA, FDA, and WAO/EAACI guidelines
Evidence Standard
Level 1A — Based on systematic reviews and randomized controlled trials (HELP Study, HELP OLE)
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No pharmaceutical funding — Independent editorial content with no commercial sponsorship
Last medical review: . Next scheduled review: February 2027. All content follows the iMedic Editorial Standards and GRADE evidence framework.