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Pegaspargase Injection

Pegaspargase (Oncaspar) is a chemotherapy enzyme used as part of combination treatment for acute lymphoblastic leukemia (ALL) in children and adults, including patients who have had allergic reactions to other asparaginase medicines.

Brand name Oncaspar
Drug class Asparagine-specific Enzyme
Rx Form 1
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026 Content updated Oct 2, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

Pegaspargase Injection at a glance The quick version — the full detail is in the Patient Information Guide below.
Dr. Brian Staiger, PharmD, BCPS
The Pharmacist’s Take By · Clinical pharmacist · Written

Pegaspargase (Oncaspar) is a chemotherapy enzyme in combination treatment for acute lymphoblastic leukemia (ALL) in children and adults, including people allergic to other asparaginase products. It has been used since about 1994, is not available as a generic, and starves leukemia cells of asparagine, an amino acid they largely cannot make, while normal cells make their own. It is hard on the body, but most common effects show up on blood tests (raised liver enzymes, high blood sugar and triglycerides, clotting changes) rather than as symptoms, and rash or hives can appear around a dose. Act fast on severe or worsening belly pain, a possible sign of pancreatitis, which can be fatal.

Clinical pearls

  • Each dose is given in clinic, with pre-dose medicines and at least an hour of watching for anaphylaxis (a severe allergic reaction).
  • Report leg swelling, sudden headache, vision changes or trouble speaking right away, since blood clots, including in the brain, can occur.
  • Rapid weight gain or a swollen, painful belly can signal veno-occlusive disease, where blood flow through the liver gets blocked.
  • It can raise levels of dexamethasone, a steroid often given alongside it, increasing the risk of osteonecrosis (bone damage).
How we write & review this content — our editorial policy →
How you get itPrescription only
Comes asInjection
Earliest FDA record1994
Companies listing it with the FDA1
FDA label last updatedOct 7, 2024
FDA’s strongest warning (boxed)None on the label

Patient information guide A plain-language walkthrough of Pegaspargase Injection, written from its FDA label.

What Pegaspargase Injection is used for

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Pegaspargase (Oncaspar) injection is approved for use in combination with other chemotherapy medicines to treat acute lymphoblastic leukemia (ALL). It covers the following specific situations:

  • Oncaspar is used as part of a multi-drug chemotherapy regimen for the first-line (initial) treatment of ALL in both pediatric and adult patients.
  • Oncaspar is used as part of a multi-drug chemotherapy regimen for ALL in pediatric and adult patients who have developed hypersensitivity (allergic reactions) to native forms of L-asparaginase — giving patients a treatment option when other asparaginase products are no longer tolerable.

How Pegaspargase Injection works

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Pegaspargase is an enzyme — a protein that drives a chemical reaction in the body. It works by breaking down L-asparagine, an amino acid (a protein building block) found in the bloodstream. Leukemia cells have a low ability to make their own asparagine, so they depend on grabbing it from the blood to survive and grow. By rapidly depleting asparagine levels in plasma (blood) and cerebrospinal fluid (the fluid around the brain and spine), pegaspargase essentially cuts off leukemia cells' fuel supply, causing them to die. Normal cells, which can produce asparagine on their own, are largely able to compensate.

Pegaspargase Injection dosage

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Oncaspar is always given by a healthcare team in a clinical setting — never at home. It can be injected into a muscle (intramuscular) or infused into a vein (intravenous), with the route chosen by your care team. It is given no more frequently than every 14 days as part of a broader chemotherapy schedule.

  • Before each dose, patients receive pre-medications (such as acetaminophen and antihistamines) to reduce the risk of allergic reactions.
  • After each dose, patients are monitored for at least 1 hour in the clinical setting.
  • Blood tests (liver enzymes, bilirubin, blood sugar, and clotting levels) are checked at least weekly during treatment cycles.
  • Follow your care team's schedule exactly; your oncologist will manage any missed or adjusted doses.

Dosing details from the FDA-approved label

From the Pegaspargase Injection prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.

  • Patients 21 years of age or younger
    • 2,500 International Units/m2 intramuscularly or intravenously no more frequently than every 14 days
  • Patients more than 21 years of age
    • 2,000 International Units/m2 intramuscularly or intravenously no more frequently than every 14 days
Read the label’s full dosing text

2 DOSAGE AND ADMINISTRATION Administered intramuscularly or intravenously no more frequently than every 14 days. ( 2.1 ) Patients ages 21 years and younger: 2,500 International Units/m 2 . ( 2.1 ) Patients ages over 21 years: 2,000 International Units/m 2 . ( 2.1 ) For intramuscular administration, limit the volume at a single injection site to 2 mL; if greater than 2 mL, use multiple injection sites. ( 2.3 ) For intravenous administration, give over a period of 1 to 2 hours in 100 mL of 0.9% Sodium Chloride Injection, USP or 5% Dextrose Injection, USP through an infusion that is already running. ( 2.3 ) Do not administer ONCASPAR if drug has been frozen, stored at room temperature for more than 48 hours, or shaken or vigorously agitated. ( 16 ) 2.1 Recommended Dosage Patients 21 Years of Age or Younger The recommended dose of ONCASPAR for patients up to and including 21 years of age is 2,500 International Units/m 2 intramuscularly or intravenously no more frequently than every 14 days. Patients More Than 21 Years of Age The recommended dose of ONCASPAR for adult patients more than 21 years of age is 2,000 International Units/m 2 intramuscularly or intravenously no more frequently than every 14 days. 2.2 Recommended Premedication Premedicate patients with acetaminophen, an H-1 receptor blocker (such as diphenhydramine), and an H-2 receptor blocker (such as famotidine) 30-60 minutes prior to administration of ONCASPAR to decrease the risk and severity of both infusion and hypersensitivity reactions [see Warnings and Precautions (5.1) ] . 2.3 Recommended Monitoring and Dosage Modifications for Adverse Reactions Monitor patients at least weekly, with bilirubin, transaminases, glucose and clinical examinations until recovery from the cycle of therapy. If an adverse reaction should occur, modify treatment according to Table 1. Table 1. Dosage Modifications Adverse Reaction Severity Grade 1 is mild, grade 2 is moderate, grade 3 is severe, and grade 4 is life-threatening.

Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →

Pegaspargase Injection side effects

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The most common serious side effects seen in clinical studies with Oncaspar include:

Common side effects

  • Elevated liver enzymes (transaminases)
  • Low albumin levels (hypoalbuminemia)
  • High blood sugar (hyperglycemia)
  • High triglycerides (hypertriglyceridemia)
  • Abnormal clotting test results
  • Increased bilirubin (causing possible jaundice)
  • Febrile neutropenia (fever with low white blood cell count)
  • Allergic reactions including rash, hives, or swelling
  • Increased bilirubin — can cause yellowing of skin or eyes
  • Abnormal clotting studies — affecting the blood's ability to clot properly
  • Febrile neutropenia — fever combined with very low infection-fighting white blood cells
  • Allergic reactions — ranging from rash and hives to serious anaphylaxis
  • Blood clots and embolic events
  • Pancreatitis — inflammation of the pancreas

When to get medical help

  • Call 911 or get emergency help for severe allergic reactions: trouble breathing, throat tightening, severe rash, or sudden drop in blood pressure
  • Call your doctor right away for severe or increasing abdominal (belly) pain — this could be pancreatitis, which can be life-threatening
  • Tell your care team immediately if you have signs of a blood clot: leg swelling or pain, sudden headache, vision changes, or difficulty speaking
  • Report unusual or severe bleeding, easy bruising, or blood in urine or stool right away
  • Tell your team about rapid weight gain, swelling, or stomach swelling with pain — these could be signs of serious liver disease (hepatic veno-occlusive disease)
  • Notify your doctor if blood sugar rises sharply — some cases of glucose intolerance may be permanent
  • Report signs of serious infection such as high fever, chills, or feeling extremely unwell

Pegaspargase Injection warnings and precautions

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  • Anaphylaxis and serious allergic reactions: Can occur during or after each dose. Patients are pre-medicated and observed for 1 hour in a setting with emergency equipment. The risk is higher in patients with prior reactions to E. coli-derived asparaginase. Discontinue Oncaspar permanently for severe reactions.
  • Pancreatitis: Inflammation of the pancreas — including hemorrhagic (bleeding) and necrotizing (tissue-destroying) forms — has been fatal. Watch for worsening belly pain and seek care immediately. If pancreatitis is confirmed, Oncaspar must not be restarted.
  • Thrombosis (blood clots): Serious clots, including in brain blood vessels (sagittal sinus thrombosis), have occurred. Discontinue Oncaspar permanently for severe thrombotic events.
  • Hepatotoxicity and veno-occlusive disease (VOD): Serious, potentially fatal liver damage — including VOD, where blood flow through the liver is blocked — has been reported. Signs include rapid weight gain, swelling, and rising bilirubin. Liver tests are monitored throughout treatment and for 6 weeks after the last dose.
  • Hemorrhage (serious bleeding): Clotting abnormalities can lead to dangerous bleeding. Clotting factors are monitored; the drug may need to be stopped for severe bleeding.
  • Glucose intolerance: Blood sugar can rise significantly; in some patients this may not fully reverse after treatment ends. Blood glucose is monitored regularly.

Pegaspargase Injection interactions

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Oncaspar has a known interaction with at least one class of drugs commonly used alongside it in chemotherapy regimens:

  • Glucocorticoids (e.g., dexamethasone): Pegaspargase may increase how much dexamethasone the body is exposed to, potentially raising the risk of glucocorticoid-related side effects — including osteonecrosis (bone damage, especially in joints like the hip).

Interactions listed in the FDA-approved label

From the Pegaspargase Injection prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.

  • Glucocorticoids: Pegaspargase may increase the risk of glucocorticoid-induced toxicities, including osteonecrosis through a potential increase in exposure of dexamethasone.
Read the label’s full interactions text

7 DRUG INTERACTIONS 7.1 Glucocorticoids Pegaspargase may increase the risk of glucocorticoid-induced toxicities, including osteonecrosis through a potential increase in exposure of dexamethasone [see Adverse Reactions (6.3) ] .

Read the full Drug Interactions section on DailyMed →

Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.

Check Pegaspargase Injection against a supplement or herb →

Before taking Pegaspargase Injection

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  • History of serious allergic reaction to Oncaspar or its ingredients: Do not use — this is a contraindication.
  • History of serious blood clots with any prior asparaginase therapy: Do not use.
  • History of pancreatitis, including from prior asparaginase treatment: Do not use.
  • History of serious bleeding with prior asparaginase therapy: Do not use.
  • Severe liver impairment: Do not use.
  • Pregnancy: Oncaspar can harm a fetus. Pregnancy testing is recommended before starting treatment. Use effective non-hormonal contraception during treatment and for 3 months after the last dose.
  • Breastfeeding: Do not breastfeed during treatment or for 1 month after the last dose due to potential risk to the infant.
  • Pediatric patients: Safety and effectiveness have been established in children; Oncaspar is commonly used in pediatric ALL treatment.
  • Kidney or liver impairment (other than severe liver impairment): The effect of kidney or liver problems on how the body processes pegaspargase is not fully known; discuss your full medical history with your care team.

Pegaspargase Injection overdose

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In reported cases where patients received doses much higher than recommended, reactions included a mild rise in liver enzymes and, in one case, a rash that responded to antihistamine treatment and a slower infusion rate; one patient had no reaction at all. There is no specific antidote for a pegaspargase overdose. If too much is given, the healthcare team will monitor closely and treat any symptoms that arise with supportive care.

What Pegaspargase Injection does in the body

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Oncaspar works by drastically lowering asparagine levels in the blood and spinal fluid. In clinical studies, asparagine in plasma was reduced below detectable levels for at least 11 days after a single dose during the induction phase of treatment. Levels in the cerebrospinal fluid (the fluid around the brain and spine) also dropped significantly within 4 days of dosing and stayed low for at least 25 days — important for reaching leukemia cells that may hide in the central nervous system.

How your body processes Pegaspargase Injection

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After an intramuscular (IM) injection, pegaspargase is absorbed gradually, with peak enzyme activity reached around Day 5, and the drug remains active in the body for roughly 5–6 days on average (half-life of about 5.8 days). When given intravenously (IV), it reaches peak levels more quickly, with a similar half-life of about 5.3 days. Because of this long duration of action, doses are spaced at least 14 days apart. How kidney or liver disease affects the body's processing of this drug is not yet fully understood.

How to store Pegaspargase Injection

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Store ONCASPAR refrigerated at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light. stored at room temperature (15°C to 25°C ) for no more than 48 hours.

Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

Pegaspargase Injection: pharmacist answers to common questions

Quick, plain-English answers to the questions patients ask most about Pegaspargase Injection — the kind of thing our pharmacy team would talk through with you at the counter.

What exactly is Oncaspar treating, and why is it part of my chemotherapy?

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Oncaspar targets acute lymphoblastic leukemia — a cancer where the bone marrow makes too many abnormal white blood cells. It works by cutting off a key nutrient (asparagine) that leukemia cells need to survive. It's never used alone; it's one piece of a carefully designed combination chemotherapy plan, which is why your oncologist is coordinating it with other drugs. Think of it as starving the cancer cells while the other drugs attack from different angles.

Why do I have to stay at the clinic for an hour after each dose?

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Oncaspar can sometimes trigger serious allergic reactions — including anaphylaxis, a sudden whole-body reaction that can affect your breathing and blood pressure. That hour of observation is a safety measure: the clinic has the equipment and medications (like epinephrine) to treat a reaction right away if one occurs. You'll also receive pre-medications before each dose specifically to lower the odds of a reaction happening. It's precautionary, but it's an important one.

What side effects should I watch for at home and call about right away?

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The big ones to call about immediately are: severe belly pain (could be pancreatitis — an emergency), sudden headache or swelling and pain in your leg (possible blood clot), unusual or heavy bleeding, difficulty breathing or a sudden rash after leaving the clinic (delayed allergic reaction), rapid weight gain with swelling (could signal liver problems), or a high fever with chills (serious infection). Milder things like elevated blood sugar or changes in labs will be caught by your regular blood tests, so keep those appointments.

I'm of childbearing age — what do I need to know about pregnancy during this treatment?

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This is really important: Oncaspar can cause serious harm to a developing baby. If there's any chance you could be pregnant, your team will test you before starting. During treatment and for 3 months after your last dose, you'll need to use effective birth control — and specifically non-hormonal methods, since hormonal options interact with the chemotherapy regimen. If you're breastfeeding, you'll need to stop during treatment and for 1 month after the final dose. Talk openly with your doctor — this is a routine but critical conversation before starting.

I've had a bad reaction to asparaginase before — is Oncaspar safe for me?

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Actually, one of the main reasons Oncaspar exists is for patients who've had allergic reactions to other (native) forms of asparaginase. The pegylation — a chemical modification to the drug — makes it less likely to trigger the immune system. That said, reactions can still happen, which is why you're always monitored closely after each dose. If you've had a serious reaction specifically to Oncaspar itself in the past, though, it cannot be used again — let your team know your full history so they can plan accordingly.

How will my doctors know if Oncaspar is affecting my liver or other organs?

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Your care team will run blood tests at least once a week during treatment cycles — checking liver enzymes, bilirubin, blood sugar, clotting factors, and more. These tests can catch problems early, often before you feel any symptoms. If results start trending in a concerning direction, your team may adjust your dose, pause treatment, or in serious cases stop Oncaspar altogether. Monitoring continues for up to 6 weeks after your last dose because liver effects can develop or persist even after the drug is finished.

Is Pegaspargase Injection available over the counter?

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No. Pegaspargase Injection is a prescription medicine: every Pegaspargase Injection product listed with the FDA is prescription only, so it is not sold over the counter. Your prescriber decides whether it is appropriate for you, and your pharmacist dispenses it.

When was Pegaspargase Injection first available?

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The earliest FDA record we hold for Pegaspargase Injection is from 1994: its first approval in Drugs@FDA or its earliest product listing in the NDC Directory, whichever is older. Many older medicines were in use before their first formal FDA approval, so this is the earliest date on record, not necessarily when Pegaspargase Injection was first used.

Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

More about Pegaspargase Injection on HelloPharmacist

🌿Drug & Supplement CheckerPegaspargase Injection vs. vitamins & herbs 💬Ask a PharmacistFree answer, usually < 24h 🔎NDC & pricing lookupFind Pegaspargase Injection NDCs & costs 🅰️Browse Drugs A–ZLook up any medication
Detailed data & references for Pegaspargase Injection Forms & strengths, pricing, billing codes, manufacturers, safety reports and sourcing — the data behind the page. Most people can stop here. Each section below opens on a tap.

Pegaspargase Injection forms and strengths (how it comes)

Pegaspargase Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Pegaspargase Injection inactive ingredients by manufacturer.

Injection

Into a muscle · Into a vein
Brands Oncaspar
How this form is used
What it may be used for
  • Oncaspar is used as part of a multi-agent chemotherapy regimen for first-line treatment of acute lymphoblastic leukemia (ALL) in pediatric and adult patients
  • Oncaspar is used as part of a multi-agent chemotherapy regimen for ALL in pediatric and adult patients who have had a hypersensitivity reaction to native L-asparaginase
Important instructions
  • Oncaspar is given intramuscularly (into a muscle) or intravenously (into a vein) no more often than every 14 days
  • When Oncaspar is given intramuscularly, the volume at any single injection site is limited to 2 mL; larger volumes require multiple injection sites
  • When Oncaspar is given intravenously, it is diluted and infused over 1–2 hours through an already-running IV line; no other drugs should be infused through the same line at the same time
  • Oncaspar must never be used if it has been frozen, left at room temperature for more than 48 hours, or shaken or vigorously agitated — discard the vial if any of those occurred
Available strengths 1 strength
750 [IU]/mL
3 FDA-listed product records ⓘ

Pegaspargase Injection on the U.S. market: products, makers and brands

How Pegaspargase Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

1 company lists 1 Pegaspargase Injection product record with the FDA, mostly as injection; the earliest marketing or approval year on record is 1994. Brand names on the directory include Oncaspar; the rest are generics.

1
Dose forms ⓘ
1
Labelers (makers, repackagers, distributors)
1
Brand names
1
FDA-listed product records ⓘ
1994
Earliest FDA record ⓘ

Compare Pegaspargase Injection products

A representative set of FDA-listed product records for Pegaspargase Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Strength Route Manufacturer / Labeler Category ⓘ Details
💊Injection
750 [IU]/mL Intramuscular, Intravenous Servier Pharmaceuticals LLC BLA View NDC →

Showing 1 of 1 products — FDA National Drug Code Directory. See every product, package size and price: browse all 1 Pegaspargase Injection NDCs →

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.

Ingredient (IN) Pegaspargase Injection RxCUI 34132 1 dose form · 1 strength
  1. Dose form (SCDF) Injection RxCUI 1728058 In current FDA listings
    Clinical drug / strength (SCD) 5 ML pegaspargase 750 UNT/ML RxCUI 240906

Look up RxCUI 34132 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

Pegaspargase Injection brand names

Pegaspargase Injection is sold under one brand name in the FDA directory — Oncaspar. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.

Oncaspar

Who makes Pegaspargase Injection: manufacturers and labelers

One company lists Pegaspargase Injection products with the FDA. By number of product records, the largest are Servier Pharmaceuticals LLC. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.

Servier Pharmaceuticals LLC 1

Pegaspargase Injection drug class (RxNorm)

Pegaspargase Injection belongs to the Asparagine-specific Enzyme class.

Pharmacologic class Asparagine-specific Enzyme
Drug family (ATC) Other antineoplastic agents

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

Sources for this Pegaspargase Injection page

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Oct 7, 2024
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Pegaspargase Injection.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
🚨
Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Pegaspargase Injection after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
1
Finished products in the current FDA directory
1
Companies listing them (makers, repackagers, distributors)
1
FDA labeler codes behind them ⓘ
1
Linked representative label ⓘ
Servier Pharmaceuticals LLC
Linked label effective
Oct 7, 2024
Composite sections available
22
Linked SPL Set ID
ac7b6a6f-6ddb-48c6-8088-d8a8e3fea6ce
Linked SPL Document ID
f0a8a9ab-8203-47aa-abbe-54614c201d48
Open the linked representative label on DailyMed ↗
NDC package records associated with this linked SPL 1

How this page is built

HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Servier Pharmaceuticals LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →