Oxlumo (Lumasiran)
RNA interference therapeutic for primary hyperoxaluria type 1 (PH1)
Quick facts about Oxlumo
Key takeaways about Oxlumo
- First-in-class treatment: Oxlumo is the first approved RNAi therapy specifically targeting primary hyperoxaluria type 1, offering a disease-modifying approach rather than symptomatic relief
- Effective oxalate reduction: Clinical trials demonstrated significant and sustained reductions in urinary oxalate levels, the primary driver of PH1 disease progression
- Suitable for all ages: Approved for adults and children of all ages, including infants, with weight-based dosing to ensure appropriate treatment across the lifespan
- Convenient maintenance dosing: After initial monthly loading doses, most patients receive maintenance injections only once every three months
- Generally well tolerated: The most common side effects are injection site reactions and abdominal discomfort, which are typically mild and transient
What Is Oxlumo and What Is It Used For?
Oxlumo (lumasiran) is an RNA interference (RNAi) therapeutic used to treat primary hyperoxaluria type 1 (PH1), a rare genetic disorder where the liver produces excessive amounts of oxalate. By reducing the enzyme glycolate oxidase, Oxlumo lowers oxalate levels in the urine and blood, helping to prevent kidney stones and kidney damage.
Oxlumo contains the active substance lumasiran, a small interfering RNA (siRNA) molecule designed to target a specific gene in liver cells. It represents a groundbreaking approach to treating PH1, which is caused by a deficiency of the liver enzyme alanine-glyoxylate aminotransferase (AGT). This enzyme deficiency leads to the overproduction of oxalate, a waste product that the body cannot break down and must excrete through the kidneys.
Understanding Primary Hyperoxaluria Type 1
Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive genetic disorder affecting approximately 1 to 3 per million people worldwide. The condition is caused by mutations in the AGXT gene, which encodes the enzyme AGT. Without functioning AGT, the liver produces excessive oxalate through an alternative metabolic pathway involving the enzyme glycolate oxidase (GO).
In healthy individuals, the kidneys efficiently excrete small amounts of oxalate in the urine. In PH1 patients, however, the markedly elevated oxalate levels overwhelm the kidneys' excretory capacity. The excess oxalate combines with calcium to form calcium oxalate crystals, which deposit in the kidneys and urinary tract. Over time, this leads to recurrent kidney stones (nephrolithiasis), kidney calcification (nephrocalcinosis), and progressive decline in kidney function. If left untreated, PH1 can ultimately result in kidney failure.
When kidney function deteriorates significantly, the kidneys can no longer adequately remove oxalate from the blood. Oxalate then accumulates throughout the body — a condition known as systemic oxalosis. Oxalate crystals can deposit in the bones, eyes, heart, skin, and other organs, causing severe and potentially life-threatening complications including bone disease, retinopathy, cardiac conduction defects, and skin ulceration.
How Oxlumo Works
Lumasiran employs RNA interference (RNAi) technology, a naturally occurring biological process in which small RNA molecules silence specific genes by degrading their messenger RNA (mRNA). Specifically, lumasiran targets the hydroxyacid oxidase 1 (HAO1) mRNA in hepatocytes (liver cells).
By silencing HAO1, lumasiran reduces the production of the enzyme glycolate oxidase (GO). This enzyme catalyzes the conversion of glycolate to glyoxylate — a key step in the metabolic pathway that leads to oxalate production. With less GO available, less glyoxylate is produced, and consequently, less oxalate is generated. The result is a significant and sustained reduction in both urinary and plasma oxalate levels.
Importantly, lumasiran acts upstream of the metabolic defect in PH1. Rather than trying to replace the missing AGT enzyme or remove oxalate after it is produced, it prevents the excessive production of oxalate at its source. This mechanism makes Oxlumo a disease-modifying therapy that addresses the underlying pathophysiology of PH1.
Oxlumo uses GalNAc (N-acetylgalactosamine) conjugate technology to deliver lumasiran specifically to liver cells. This targeted delivery system ensures that the drug reaches the hepatocytes where oxalate overproduction occurs, while minimizing effects on other tissues. The GalNAc ligand binds to the asialoglycoprotein receptor, which is abundantly expressed on the surface of hepatocytes.
What Should You Know Before Taking Oxlumo?
Before receiving Oxlumo, inform your healthcare provider about any allergies, kidney problems, pregnancy, or breastfeeding. Oxlumo should not be used if you are severely allergic to lumasiran or any of its other ingredients. Patients with severely impaired kidney function may need monitoring for metabolic acidosis.
Contraindications
Oxlumo must not be used if you have a serious allergy (hypersensitivity) to lumasiran or to any of the other ingredients in the medicine. The inactive ingredients include water for injections, sodium hydroxide (E524), and phosphoric acid (E338). If you have experienced a severe allergic reaction to any of these components in the past, you should not receive Oxlumo.
If you are unsure whether you may be allergic to any of the ingredients, consult your healthcare provider before receiving the injection. Although allergic reactions to Oxlumo are uncommon, signs to watch for include skin rash, throat irritation, and watery eyes. Report any unusual symptoms to your healthcare team immediately.
Warnings and Precautions
Talk to your healthcare provider before using Oxlumo if you have any existing medical conditions, particularly kidney-related problems. Your physician may need to monitor you for signs of metabolic acidosis (a buildup of acid in the body) if you have severely impaired kidney function. Metabolic acidosis can cause symptoms such as rapid breathing, confusion, fatigue, and nausea.
Patients who are already on dialysis or have end-stage kidney disease should be closely monitored throughout treatment. While Oxlumo works to reduce oxalate production, it cannot reverse existing kidney damage. Your healthcare team will assess whether Oxlumo is appropriate for your specific clinical situation and may adjust monitoring schedules accordingly.
It is important to continue attending all scheduled medical appointments during treatment with Oxlumo. Regular blood and urine tests will be needed to assess your oxalate levels and kidney function, ensuring that the medication is working effectively and that no complications arise.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to have a baby, seek advice from your healthcare provider before receiving Oxlumo. Your physician will weigh the expected health benefits for you against the potential risks to your unborn child before deciding whether treatment should proceed.
Oxlumo may pass into breast milk and could potentially affect your baby. If you are breastfeeding, consult your healthcare provider before using this medicine. Together, you and your doctor will decide whether you should stop breastfeeding or discontinue the treatment, taking into account the importance of the medicine for your health and the benefits of breastfeeding for your child.
Driving and Using Machines
Oxlumo is unlikely to have any effect on your ability to drive vehicles or operate machinery. No studies on driving performance have been conducted, but based on the pharmacological properties and the observed side effect profile of lumasiran, no impairment is expected.
Sodium Content
Oxlumo contains less than 1 mmol (23 mg) sodium per mL, meaning it is essentially sodium-free. This is important for patients on sodium-restricted diets, as the negligible sodium content means Oxlumo will not meaningfully contribute to their daily sodium intake.
How Does Oxlumo Interact with Other Drugs?
No clinically significant drug interactions have been identified for Oxlumo (lumasiran). However, you should always inform your healthcare provider about all medications you are currently taking, have recently taken, or plan to take, including prescription drugs, over-the-counter medicines, and herbal supplements.
Lumasiran acts through a highly specific mechanism of RNA interference within liver cells, targeting only the HAO1 mRNA. Because of this targeted mechanism, it does not interact with the cytochrome P450 (CYP) enzyme system or other common drug metabolism pathways. Clinical studies and post-marketing experience have not identified any significant interactions with other medications.
Nevertheless, it remains important to provide your healthcare team with a complete list of all medicines you are using. This includes any supplements, vitamins, or herbal products. Although no interactions are known, comprehensive medication histories help healthcare providers deliver the safest and most effective care possible.
Patients with PH1 may be taking other medications to manage their condition, such as pyridoxine (vitamin B6) supplements, which can reduce oxalate production in some PH1 patients who are responsive to this vitamin. Your healthcare provider will determine whether to continue pyridoxine therapy alongside Oxlumo treatment based on your individual clinical response.
While Oxlumo has no known drug interactions, patients with PH1 often take multiple medications to manage their kidney health and related complications. Keep an up-to-date list of all your medications and share it with every healthcare provider involved in your care, including dentists and pharmacists.
What Is the Correct Dosage of Oxlumo?
Oxlumo dosing is weight-based. Treatment begins with 3 monthly loading doses, followed by maintenance doses. For patients weighing 20 kg or more, the loading and maintenance dose is 3 mg/kg. For patients weighing less than 20 kg, the loading dose is 6 mg/kg, with maintenance dosing frequency varying by weight category.
Your healthcare provider will calculate the exact dose of Oxlumo based on your body weight. The dose may be adjusted if your weight changes significantly over time. Treatment is divided into two phases: a loading phase and a maintenance phase.
Loading Phase
During the loading phase, you will receive injections once per month for a total of 3 doses. The purpose of loading doses is to rapidly reduce glycolate oxidase levels and achieve a meaningful reduction in oxalate production. The loading dose depends on body weight:
| Body Weight | Dose | Frequency | Number of Doses |
|---|---|---|---|
| Less than 10 kg | 6 mg/kg | Once monthly | 3 doses |
| 10 kg to less than 20 kg | 6 mg/kg | Once monthly | 3 doses |
| 20 kg or more | 3 mg/kg | Once monthly | 3 doses |
Maintenance Phase
One month after the last loading dose, you will begin receiving maintenance doses. The maintenance dosing frequency depends on your body weight:
| Body Weight | Dose | Frequency |
|---|---|---|
| Less than 10 kg | 3 mg/kg | Once monthly |
| 10 kg to less than 20 kg | 6 mg/kg | Once every 3 months (quarterly) |
| 20 kg or more | 3 mg/kg | Once every 3 months (quarterly) |
Children
Oxlumo is approved for use in patients of all ages, including neonates, infants, children, and adolescents. The dosage is the same weight-based regimen described above. Clinical trials included pediatric patients across all age groups and demonstrated consistent efficacy and safety. No age-specific dose adjustments are necessary beyond the weight-based calculations.
For very young patients weighing less than 10 kg, the maintenance dose is administered monthly rather than quarterly, as these patients require more frequent dosing to maintain adequate suppression of glycolate oxidase. Your child's healthcare team will carefully monitor their response and adjust the schedule if their weight changes.
Elderly
PH1 is predominantly diagnosed in childhood and early adulthood. Limited data are available for elderly patients. However, no specific dose adjustments are recommended based on age alone. As with all patients, the dose is determined by body weight, and kidney function should be monitored regularly.
How Oxlumo Is Administered
Oxlumo is administered as a subcutaneous injection (under the skin) by a healthcare professional. The injection is typically given in the abdomen, and in some cases, in the upper arm or thigh. Your healthcare provider will rotate the injection site to minimize local reactions.
Depending on your prescribed dose, more than one subcutaneous injection may be needed at a single visit. The maximum acceptable volume for a single injection is 1.5 mL. If more than 1.5 mL is required, the dose will be split across multiple injection sites, spaced at least 2 cm apart. Your healthcare provider will not inject into skin areas that are scarred, red, inflamed, or swollen.
Missed Dose
If you miss a scheduled dose of Oxlumo, contact your healthcare provider as soon as possible to arrange an appointment for your next injection. It is important to stay on schedule to maintain consistent reduction of oxalate levels. Your healthcare team will advise you on the best time for your next dose.
Overdose
In the unlikely event that you receive more Oxlumo than prescribed, your healthcare team will monitor you for any adverse effects. There is no specific antidote for lumasiran overdose. Treatment would be supportive and based on any symptoms that develop. In clinical trials, doses higher than the recommended dose have been administered without significant additional adverse effects, but medical supervision following an overdose is still essential.
What Are the Side Effects of Oxlumo?
The most common side effects of Oxlumo are injection site reactions (affecting more than 1 in 10 patients) such as redness, pain, itching, and swelling, and abdominal pain. These are generally mild to moderate and resolve on their own. Hypersensitivity reactions have been reported at an unknown frequency.
Like all medicines, Oxlumo can cause side effects, although not everybody gets them. Most side effects associated with Oxlumo are mild to moderate in severity and tend to resolve without specific treatment. The following side effects have been reported during clinical trials and post-marketing surveillance:
Very Common
May affect more than 1 in 10 people
- Injection site reactions: redness (erythema), pain, itching (pruritus), swelling, discomfort, discoloration, lumps (nodules), hardening (induration), rash, bruising, or peeling at the injection site
- Abdominal pain: pain, tenderness, or discomfort in the stomach area
Frequency Not Known
Frequency cannot be estimated from available data
- Hypersensitivity reactions: a type of allergic reaction with symptoms such as rash, throat irritation, and watery eyes
Injection Site Reactions
Injection site reactions are the most commonly reported side effect of Oxlumo. These reactions occur at or near the site where the injection was given and may include any combination of redness, pain, itching, swelling, discomfort, changes in skin color, formation of small lumps, hardening of the skin, rash, bruising, or peeling.
These reactions are usually mild to moderate in intensity and resolve on their own within a few days. Your healthcare provider will rotate injection sites at each visit to help minimize the occurrence and severity of these reactions. If you experience a particularly bothersome reaction, inform your healthcare provider, who may recommend appropriate local management such as a cool compress or topical treatment.
Abdominal Pain
Some patients experience stomach pain, tenderness, or discomfort after receiving Oxlumo. This side effect is typically mild and temporary. If abdominal pain is severe, persistent, or accompanied by other symptoms such as fever, vomiting, or changes in bowel habits, contact your healthcare provider promptly for evaluation.
Hypersensitivity Reactions
In rare cases, patients may experience an allergic-type (hypersensitivity) reaction to Oxlumo. Symptoms may include skin rash, throat irritation, and watery or runny eyes. The frequency of these reactions cannot be precisely determined from available data. If you experience signs of an allergic reaction after receiving Oxlumo, seek medical attention immediately.
Reporting suspected side effects after a medicine has been approved is important. It allows continued monitoring of the benefit-risk balance of the medicine. Patients and healthcare professionals are encouraged to report any suspected adverse reactions through their national pharmacovigilance system, such as the FDA MedWatch program (United States), the Yellow Card Scheme (United Kingdom), or the EMA's EudraVigilance system (European Union).
How Should You Store Oxlumo?
Oxlumo should be stored at or below 30°C (86°F), in the original carton to protect from light. It is for single use only and should be used immediately after opening. Keep out of the sight and reach of children.
Proper storage of Oxlumo is essential to ensure the medicine remains effective and safe. The following storage guidelines should be observed:
- Temperature: Store at or below 30°C (86°F). Do not freeze the solution.
- Light protection: Keep the vial in the outer carton to protect it from light, as lumasiran may degrade when exposed to light for extended periods.
- Single use only: Each vial is intended for one-time use. After the vial has been opened, use the solution immediately. Do not save unused medicine for later use.
- Expiration date: Do not use Oxlumo after the expiration date printed on the carton and vial label (after "EXP"). The expiration date refers to the last day of that month.
- Out of reach of children: Always store this medicine where children cannot see or reach it.
- Disposal: Do not dispose of Oxlumo via wastewater or household waste. Your healthcare provider or pharmacist will safely dispose of any unused medicine. These measures help protect the environment.
In most cases, Oxlumo will be stored and administered at a healthcare facility, so storage requirements will be managed by your healthcare team. If you have questions about how your medicine is being stored, do not hesitate to ask your healthcare provider.
What Does Oxlumo Contain?
Oxlumo contains lumasiran sodium as the active ingredient (equivalent to 94.5 mg lumasiran per vial). The inactive ingredients are water for injections, sodium hydroxide (E524), and phosphoric acid (E338). The solution is a clear, colorless to yellow liquid for subcutaneous injection.
Active Ingredient
Each single-use vial contains lumasiran sodium, equivalent to 94.5 mg of lumasiran in 0.5 mL of solution. Lumasiran is a double-stranded small interfering RNA (siRNA) that is chemically modified for stability and conjugated to a GalNAc (N-acetylgalactosamine) ligand for targeted liver delivery.
Inactive Ingredients (Excipients)
The other ingredients in Oxlumo are:
- Water for injections — serves as the solvent for the solution
- Sodium hydroxide (E524) — used for pH adjustment
- Phosphoric acid (E338) — used for pH adjustment
Appearance and Packaging
Oxlumo is a clear, colorless to yellow solution for subcutaneous injection. Each carton contains one single-use glass vial with 0.5 mL of solution. The medicine should be visually inspected before use; do not use if the solution is discolored, cloudy, or contains visible particles.
Oxlumo is manufactured by Alnylam Netherlands B.V., Amsterdam, The Netherlands. The marketing authorization is held by Alnylam Pharmaceuticals, and the product is distributed globally under various regulatory approvals including EMA (European Medicines Agency) and FDA (U.S. Food and Drug Administration) authorization.
Frequently Asked Questions About Oxlumo
Oxlumo (lumasiran) is used for the treatment of primary hyperoxaluria type 1 (PH1) in adults and children of all ages. PH1 is a rare genetic disorder where the liver produces too much oxalate, leading to kidney stones, kidney damage, and potentially systemic oxalosis. Oxlumo works by reducing the enzyme responsible for oxalate overproduction in the liver using RNA interference technology.
Oxlumo is given as a subcutaneous injection (under the skin) by a healthcare professional. The injection is usually given in the abdomen, but may also be administered in the upper arm or thigh. Treatment starts with three monthly loading doses, followed by maintenance doses. The frequency of maintenance doses depends on body weight — monthly for patients under 10 kg, and every three months for patients 10 kg and above.
The most common side effects are injection site reactions (including redness, pain, itching, swelling, and bruising) and abdominal pain. These affect more than 1 in 10 patients but are generally mild to moderate and resolve on their own. Allergic reactions (hypersensitivity) with rash, throat irritation, and watery eyes have been reported at an unknown frequency.
Yes, Oxlumo is approved for patients of all ages, including newborns, infants, children, and teenagers. The dose is calculated based on body weight, with specific dosing schedules for different weight categories. Clinical trials included pediatric patients and showed that Oxlumo is effective and well-tolerated across all age groups.
Unlike traditional PH1 management (high fluid intake, pyridoxine supplements, dialysis, and liver-kidney transplantation), Oxlumo is a disease-modifying therapy that targets the root cause of oxalate overproduction. It uses RNA interference to reduce the enzyme glycolate oxidase, directly lowering oxalate production in the liver. This represents a fundamentally different approach — preventing oxalate from being made, rather than trying to remove it or manage its consequences after production.
Oxlumo should be stored at or below 30°C (86°F) in the original carton to protect from light. It is a single-use product and should be used immediately once the vial is opened. Do not freeze. Do not use after the expiration date on the packaging. In practice, Oxlumo is usually stored and administered at a healthcare facility.
References and Sources
This article is based on the following evidence-based medical sources and international guidelines:
- European Medicines Agency (EMA). Oxlumo (lumasiran) – Summary of Product Characteristics. Available at: EMA EPAR for Oxlumo. Accessed January 2026.
- U.S. Food and Drug Administration (FDA). Oxlumo (lumasiran) Prescribing Information. Approved November 2020. Available via FDA Drug Database.
- Garrelfs SF, Frishberg Y, Hulton SA, et al. Lumasiran, an RNAi Therapeutic for Primary Hyperoxaluria Type 1. N Engl J Med. 2021;384(13):1216-1226. doi:10.1056/NEJMoa2021712
- Sas DJ, Magen D, Hayes W, et al. Phase 3 trial of lumasiran for primary hyperoxaluria type 1: A randomized clinical trial. Genet Med. 2022;24(3):654-662.
- Hoppe B, Koch A, Cochat P, et al. Safety, pharmacodynamics, and exposure-response modeling results from a first-in-human phase 1 study of lumasiran. Kidney Int. 2021;99(6):1436-1446.
- KDIGO 2024 Clinical Practice Guidelines for Management of Kidney Stones and Related Metabolic Disorders. Kidney Disease: Improving Global Outcomes.
- Cochat P, Rumsby G. Primary hyperoxaluria. N Engl J Med. 2013;369(7):649-658.
- Milliner DS, Harris PC, Lieske JC. Primary Hyperoxaluria Type 1. In: Adam MP, et al., eds. GeneReviews. University of Washington, Seattle; Updated 2023.
- World Health Organization (WHO). Model List of Essential Medicines. 23rd List, 2023. Geneva: WHO.
- British National Formulary (BNF). Lumasiran. National Institute for Health and Care Excellence (NICE). Updated 2025.
Editorial Team
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iMedic Medical Editorial Team
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