Cerezyme (imiglucerase)
An approved treatment for Gaucher Disease.
The same compound appears under different names depending on the context. Here is how to identify Imiglucerase wherever you encounter it, plus the key facts at a glance.
- Generic name
- Imiglucerase
- Brand name
- Cerezyme
- Drug class
- Enzyme replacement therapy
- Manufacturer
- Sanofi Genzyme
- How it's taken
- Given as an intravenous infusion.
The gold standard enzyme replacement therapy for Gaucher disease. Provides the glucocerebrosidase enzyme that patients lack, clearing the fatty buildup from the spleen, liver, and bone marrow.
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Where Imiglucerase fits
The original and most established enzyme replacement therapy for Gaucher disease, approved for the non-CNS manifestations of Type 1 and (since January 2026) Type 3. Long-term safety and efficacy data spanning decades of clinical use.
How Imiglucerase works
Cerezyme is a manufactured version of glucocerebrosidase, the enzyme that Gaucher patients can't produce properly. When infused into the bloodstream, the enzyme is taken up by macrophages (the cells where fatty buildup occurs) and breaks down the accumulated glucocerebroside. This reduces organ enlargement and improves blood counts and bone health.
Mechanism: Enzyme replacement therapy providing functional glucocerebrosidase enzyme
Side effects and safety
Cerezyme carries a boxed warning for hypersensitivity reactions including anaphylaxis, which can be life-threatening and can happen early in treatment or after years of therapy. Treatment is started in a healthcare setting with emergency equipment available. Other reported reactions include back pain, chills, dizziness, fatigue, headache, nausea, fever, vomiting and infusion reactions such as flushing and itching. Patients with antibodies to imiglucerase have a higher risk of allergic reactions. Generally well tolerated with over 30 years of experience.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Imiglucerase
Given as an intravenous infusion. The labeled dose ranges from 2.5 units/kg 3 times a week to 60 units/kg every 2 weeks, adjusted to disease severity; 60 units/kg every 2 weeks is a common regimen. Infusions take 1-2 hours (2 hours for children 20 kg or less) and can be administered at home after initial doses at an infusion center.
Availability and cost
Only available as the brand-name product.
Recombinant enzyme replacement therapy requiring biweekly IV infusions. Produced in CHO cells through complex biologic manufacturing for a rare lysosomal storage disorder.
Help paying for Cerezyme
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
CareConnect Copay Program helps commercially insured US patients with copays, coinsurance and deductibles up to a program maximum. Excludes Medicare, Medicaid, VA, DoD, TRICARE.
For: private insurance · source - Insurance and case manager help
Dedicated team provides disease education and help navigating health insurance, free of charge.
The official page does not say who qualifies. Ask the program. · source - Free medicine program
CareConnect Patient Assistance Program may give certain Sanofi therapies free to eligible patients without insurance or whose plan won't cover them, temporarily.
For: no insurance, underinsured · source
Good to know: Cerezyme's page says CareConnect may help eligible patients get financial assistance but does not name the free-drug program; that is described on the CareConnect site for 'certain Sanofi therapies'. Call 1-800-745-4447 (English press 3), Mon-Fri 8AM-6PM EST.
- From a charity · The Assistance FundGaucher Disease fundOpen
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “OPEN — Accepting New Patients. TAF is currently accepting new patient enrollments for this program.” - From a charity · TotalAssist (formerly PAN Foundation)Gaucher Disease fundOpen
Pays for: Out-of-pocket costs for approved medications, up to $14,000 per year. Requires health insurance (any kind).
- From a charity · NORD RareCareGaucher Disease Medical Assistance fundWaitlist
Pays for: Medical and medication costs.
The foundation says: “Temporarily Waitlisting” - From a charity · NORD RareCareGaucher Disease Premium Copay Assistance fundWaitlist
Pays for: Insurance premiums and copays.
The foundation says: “Temporarily Waitlisting”
Clinical trial results
Decades of clinical evidence demonstrate normalization of blood counts within 6-12 months, reduction in liver and spleen size within 1-2 years, and improvement in bone disease over 3-5 years. FDA expanded indication to Type 3 Gaucher disease in January 2026.
Development history
Approved by FDA in May 1994, succeeding the original alglucerase (Ceredase). Has over 30 years of clinical experience and is one of the most established rare disease treatments. The paradigm-defining enzyme replacement therapy.
Explore Gaucher Disease trials
Other Gaucher Disease treatments
Imiglucerase in Trial Friend News and Guides
Common questions about Imiglucerase
▸What is Imiglucerase (Cerezyme)?
The gold standard enzyme replacement therapy for Gaucher disease. Provides the glucocerebrosidase enzyme that patients lack, clearing the fatty buildup from the spleen, liver, and bone marrow.
▸How does Imiglucerase work?
Cerezyme is a manufactured version of glucocerebrosidase, the enzyme that Gaucher patients can't produce properly. When infused into the bloodstream, the enzyme is taken up by macrophages (the cells where fatty buildup occurs) and breaks down the accumulated glucocerebroside. This reduces organ enlargement and improves blood counts and bone health.
▸What are the side effects of Imiglucerase?
Cerezyme carries a boxed warning for hypersensitivity reactions including anaphylaxis, which can be life-threatening and can happen early in treatment or after years of therapy. Treatment is started in a healthcare setting with emergency equipment available. Other reported reactions include back pain, chills, dizziness, fatigue, headache, nausea, fever, vomiting and infusion reactions such as flushing and itching. Patients with antibodies to imiglucerase have a higher risk of allergic reactions. Generally well tolerated with over 30 years of experience.
▸How is Imiglucerase taken?
Given as an intravenous infusion. The labeled dose ranges from 2.5 units/kg 3 times a week to 60 units/kg every 2 weeks, adjusted to disease severity; 60 units/kg every 2 weeks is a common regimen. Infusions take 1-2 hours (2 hours for children 20 kg or less) and can be administered at home after initial doses at an infusion center.
▸Is Imiglucerase FDA approved?
Yes, Imiglucerase (Cerezyme) is FDA approved (1994) for the treatment of Gaucher Disease.
▸What is Cerezyme (imiglucerase) used for?
Cerezyme is approved to treat the non-central nervous system (non-CNS) manifestations of Type 1 or Type 3 Gaucher disease in adults and children.
About the disease: Gaucher disease is an inherited condition in which the body lacks a working enzyme called glucocerebrosidase, so a fatty substance builds up in the spleen, liver, bone marrow and bones.
What it treats: The enlarged organs, low blood counts and bone problems that result.
Not treated: The brain and nerve symptoms that occur in Type 3 Gaucher disease.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸How does Cerezyme work?
Cerezyme is a manufactured version of the missing enzyme, which is why it is called an enzyme replacement therapy.
Targeting: The enzyme carries mannose sugars on its surface, and those sugars act as a tag that lets macrophages (the immune cells where the fatty buildup collects) grab the enzyme and pull it inside.
Inside the cell: Imiglucerase breaks down the stored fat, called glucocerebroside, into glucose and ceramide.
Result: Clearing that buildup is what shrinks the spleen and liver and lets blood counts recover.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸How is Cerezyme made, and what is its structure?
Imiglucerase is produced by recombinant DNA technology in Chinese hamster ovary (CHO) cells, a mammalian cell line commonly used to make biologic drugs.
Structure: It is a single protein chain of 497 amino acids and is nearly identical to the natural human enzyme, differing by only 1 amino acid at position 495.
Sugar chains: During manufacturing, the sugar chains on the protein are trimmed so they end in mannose, which is the feature that targets the enzyme to macrophages.
Vial contents: Each vial contains the purified enzyme as a freeze-dried powder with mannitol, polysorbate 80 and sodium citrate.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸What is the difference between Cerezyme and Ceredase (alglucerase)?
Ceredase (alglucerase) was the original enzyme replacement therapy for Gaucher disease and was purified from human placental tissue, while Cerezyme (imiglucerase) is made in cell culture and replaced it.
Molecular differences: The 2 enzymes differ by 1 amino acid and have slightly different sugar structures.
Head-to-head trial: In a 6-month trial of 30 people with Type 1 Gaucher disease, both raised hemoglobin (1.9 vs 1.6 g/dL), raised platelet counts, and shrank the liver (11% vs 10%) and spleen (35% vs 30%) by similar amounts.
Approval: Cerezyme was approved by the FDA in May 1994 as the successor to Ceredase.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸How is a Cerezyme infusion given?
Cerezyme is given as an intravenous (IV) infusion, meaning it drips into a vein.
Preparation: The powder in each 400 unit vial is dissolved in sterile water, then diluted in saline and run through a 0.2 micron in-line filter.
Infusion time: For adults and children over 20 kg the infusion takes 1 to 2 hours, and for children 20 kg or less it takes 2 hours.
First infusions: They must be given in a healthcare setting with emergency equipment available because of the risk of severe allergic reactions.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸What is the dose of Cerezyme?
The approved dose range is wide, from 2.5 units per kg of body weight 3 times a week up to 60 units per kg once every 2 weeks.
How it is set: Your doctor sets the dose based on how severe your disease is and what treatment goals you have, and the dose can be adjusted over time.
Who directs treatment: The label says a physician experienced in Gaucher disease should direct treatment.
Trial dose: In the main clinical trial, the dose studied was 60 units per kg every other week.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸Can Cerezyme be given at home?
Home infusion can be arranged for many people after initial infusions at an infusion center to monitor for reactions.
Label requirements: Treatment must be started in a healthcare setting with medical monitoring and resuscitation equipment on hand, and every infusion must be supervised by a provider who knows how to manage anaphylaxis.
Typical schedule: Infusions typically take 1 to 2 hours every 2 weeks at a dose of 60 units per kg.
What to do: Ask your treatment team whether and when home infusion is an option for you.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸What are the side effects of Cerezyme?
The label lists back pain, chills, dizziness, fatigue, headache, nausea, fever, vomiting and hypersensitivity reactions as reported side effects in adults and children.
Infusion-related reactions: These can include itching, flushing, hives, swelling, chest discomfort, shortness of breath, cough, fast heartbeat, high or low blood pressure, and burning or swelling at the infusion site.
Why no percentages: The current label does not give percentages for these reactions because much of the data comes from voluntary reports after approval.
Contraindications: The label lists none, meaning no group of people is told outright not to use it.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸What is the boxed warning on Cerezyme?
Cerezyme carries the FDA's strongest warning for severe allergic reactions, including anaphylaxis, which can be life-threatening.
When reactions occur: These reactions have happened both early in treatment and after years of therapy, which is why treatment starts in a healthcare setting with emergency equipment and epinephrine available.
Antibodies: About 15% of people develop IgG antibodies to Cerezyme in the first year, mostly within 6 months, and about 46% of those with antibodies have had allergic symptoms.
Management: People who react may be premedicated with antihistamines or steroids, given a slower infusion, or in severe cases taken off the drug.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸What are the long-term effects of Cerezyme?
Cerezyme has been in use since 1994, giving it over 30 years of clinical experience.
Trial extension: After 18 to 24 months of treatment in the extension of the original trial, hemoglobin had risen by an average of 2.4 g/dL, platelets by 40,000 per cubic millimeter, liver volume had dropped 20% and spleen volume 57%.
Registry data: In a registry analysis of 1,052 people with Type 1 Gaucher disease treated for 1 to 3 years, hemoglobin rose by 1.5 g/dL and platelets by 64,000, with similar gains in 118 people with Type 3.
Timeline: Over the longer term, blood counts generally normalize within 6 to 12 months, organ size falls within 1 to 2 years, and bone disease improves over 3 to 5 years.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸Does Cerezyme shrink an enlarged spleen?
Yes.
Spleen: In the 6-month randomized trial, spleen volume fell by 35% on Cerezyme, from an average of 2,369 mL. After 18 to 24 months of treatment, the average reduction reached 57%.
Liver: Liver volume fell by 11% at 6 months and 20% at 18 to 24 months.
Bone: Bone x-rays also improved in 7 of 11 people examined in that trial.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸What did the Cerezyme clinical trials show?
The pivotal trial showed Cerezyme raised hemoglobin and platelets as well as the older enzyme did, and a later registry study supported extending approval to Type 3 Gaucher disease.
Pivotal trial: A randomized, double-blind study of 30 people aged 12 to 69 with Type 1 Gaucher disease who received either Cerezyme 60 units per kg every other week or alglucerase for 6 months.
Results: Hemoglobin rose 1.9 g/dL on Cerezyme and platelets rose by 22,700 per cubic millimeter, matching the older enzyme.
Registry study: The 2026 label update added a registry study (NCT00358943) of people treated from 1992 to 2021, which showed improvements in hemoglobin, platelets, liver and spleen size, and children's height after about 2 years.
Type 3 approval: That registry data supported extending approval to Type 3 Gaucher disease in January 2026.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸Does Cerezyme have a generic or biosimilar?
No, Cerezyme is a biologic made in living cells, so an ordinary generic is not possible, and no biosimilar version of imiglucerase has been approved by the FDA.
Other options: Other enzyme replacement therapies for Gaucher disease exist as separate branded products, including VPRIV and Elelyso, and an oral option called eliglustat (Cerdelga) is available for eligible patients.
Not copies: Each is a different molecule rather than a copy of Cerezyme.
▸How much does Cerezyme cost per year?
The FDA label does not list a price, and Trial Friend does not have a verified yearly cost figure.
What affects cost: Cerezyme is a specialty biologic given by infusion every 2 weeks, with the dose based on body weight, so annual cost varies widely from person to person and depends on insurance.
What to do: Contact your care team, your insurer or the manufacturer, Sanofi Genzyme, to ask about coverage and any available support programs.
▸Who makes Cerezyme, and when was it FDA approved?
Cerezyme is made by Genzyme Corporation, now part of Sanofi and often referred to as Sanofi Genzyme.
Approval history: The FDA approved it in May 1994 for Type 1 Gaucher disease, and in January 2026 the label was expanded to include the non-CNS manifestations of Type 3 Gaucher disease.
Reporting side effects: Suspected side effects can be reported to Genzyme at 1-800-633-1610 or to the FDA at 1-800-FDA-1088.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27
▸How is Cerezyme stored and supplied?
Cerezyme comes as a white to off-white freeze-dried powder in a single-use vial containing 400 units, with no preservatives.
Unopened vials: Keep refrigerated at 36°F to 46°F (2°C to 8°C).
After mixing: Once dissolved in sterile water, the solution can be refrigerated or kept at room temperature for up to 12 hours, and after it is diluted in saline it can be refrigerated for up to 24 hours.
In the body: In the bloodstream the enzyme is cleared quickly, with a half-life of only 3.6 to 10.4 minutes, because it is taken up into cells so rapidly.
Source: FDA label for Cerezyme, DailyMed, effective 2026-08-27