FDA-filed SPL labeling · retrieved through openFDA

Asparaginase Erwinia Chrysanthemi Injection

Asparaginase Erwinia Chrysanthemi Injection is an enzyme-based cancer medicine used as part of combination chemotherapy to treat acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LBL) in patients who have had an allergic reaction to E. coli-derived asparaginase.

Brand names ErwinazeRylaze
Drug class Asparagine-specific Enzyme
Rx Form 1 Route Intramuscular
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 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 →

At a glance
Linked label effectiveJul 1, 2025
AvailabilityRx
Earliest approval/marketing year 2021
FDA-listed product records 4
Boxed warningNone found in compared labels
How we combine label and product data →
No current FDA shortage listed · checked Sep 16, 2026
Asparaginase Erwinia Chrysanthemi Injection at a glance The quick version — the full detail is in the Patient Information Guide below.
💊
HelloPharmacist Editorial Team Bottom Line
Rylaze is an enzyme-based cancer treatment used in combination with other chemotherapy drugs for acute lymphoblastic leukemia and lymphoblastic lymphoma in patients who are allergic to E. coli-derived asparaginase. It is given by intramuscular injection in a clinical setting, where staff can manage potential serious reactions like severe allergic responses, pancreatitis, blood clots, bleeding, and liver toxicity. Close monitoring throughout treatment is essential, and patients should promptly report any new or worsening symptoms to their oncology team.

📖 Asparaginase Erwinia Chrysanthemi Injection: Patient Information Guide

A plain-language walkthrough of Asparaginase Erwinia Chrysanthemi Injection — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.

🎯What it's used for

Rylaze (asparaginase erwinia chrysanthemi injection) is an enzyme used as part of combination chemotherapy for certain blood cancers in patients who can no longer receive E. coli-based asparaginase due to an allergic reaction.

  • Rylaze is indicated for the treatment of acute lymphoblastic leukemia (ALL) in adults and pediatric patients 1 month of age or older who have developed hypersensitivity to E. coli-derived asparaginase
  • Rylaze is indicated for the treatment of lymphoblastic lymphoma (LBL) in adults and pediatric patients 1 month of age or older who have developed hypersensitivity to E. coli-derived asparaginase
  • Rylaze is used as a replacement for long-acting asparaginase products (such as pegaspargase or calaspargase pegol products) within a patient's overall chemotherapy plan
⚙️How it works

Rylaze is an enzyme that breaks down L-asparagine — an amino acid — in the bloodstream, converting it into aspartic acid and ammonia. Leukemic cells have low levels of an enzyme called asparagine synthetase, meaning they cannot manufacture their own asparagine and must pull it from the blood to survive. By rapidly depleting blood asparagine levels, Rylaze cuts off this critical supply, causing cancer cells to die. Normal cells are less affected because they can make their own asparagine internally.

💊How it's taken

Rylaze is given only by intramuscular injection (a shot into the muscle) in a healthcare setting — never at home or by IV. There are two approved dosing schedules: one where it is given every 48 hours, and one where it is given on a Monday, Wednesday, and Friday pattern (with the Friday dose being larger and given in the afternoon). The number of doses needed depends on which long-acting asparaginase product Rylaze is replacing and for how long. Your oncology team will determine your exact schedule. Never adjust your schedule without guidance from your care team.

  • Always given by a healthcare professional in a clinical setting
  • Injection sites are rotated with each dose to minimize local reactions
  • If a dose volume is large, it may be split into multiple injection sites
  • Premedication is given 30–60 minutes before each dose to reduce the risk of allergic reactions
🤒Side effects — in detail

Most patients receiving Rylaze as part of chemotherapy experience some side effects. Common ones include:

  • Abnormal liver tests (elevated enzymes or bilirubin)
  • Nausea or vomiting
  • Musculoskeletal pain (muscle or joint aches)
  • Fatigue or weakness
  • Headache
  • Infections (including febrile neutropenia — fever with low white blood cell counts)
  • Fever
  • Bleeding or bruising (including nosebleeds and easy bruising)
  • Decreased appetite, stomach pain, or diarrhea
  • High blood sugar (hyperglycemia) and low potassium (hypokalemia)

Serious reactions — including severe allergic reactions, pancreatitis, blood clots, significant bleeding, and liver toxicity — require immediate medical attention. All patients in clinical trials experienced some degree of low blood counts (neutropenia, anemia, or low platelets).

⚠️Warnings & precautions
  • Serious allergic reactions (hypersensitivity): Occurred in 29% of patients in trials, with severe reactions in 6% and anaphylaxis in 2%. Every dose must be given in a setting equipped to treat anaphylaxis, and patients are premedicated before each injection. Rylaze must be permanently stopped for severe (Grade 3–4) allergic reactions.
  • Pancreatitis: Occurred in 20% of patients; severe in 8%. Hemorrhagic or necrotizing (tissue-destroying) pancreatitis has been reported with this class of drugs and can be fatal. Rylaze must be held or permanently discontinued depending on severity.
  • Thrombosis (blood clots): Serious clotting events — including clots in the brain's venous sinuses and lungs — were reported in 1% of patients. Severe or life-threatening clots require permanent discontinuation and anticoagulation therapy.
  • Hemorrhage (bleeding): Occurred in 25% of patients; severe in 2%. Bleeding may be linked to clotting factor abnormalities. Severe bleeding requires Rylaze to be held and may require clotting factor replacement.
  • Hepatotoxicity (liver toxicity), including hepatic veno-occlusive disease (VOD): Elevated liver enzymes occurred in 75% of patients; severe elevations in 26%. Rare but potentially fatal VOD has been reported. Liver tests must be monitored before each treatment cycle and at least weekly during treatment. Rylaze must be discontinued in severe liver toxicity.
🔀What it interacts with

The FDA label for Rylaze does not specify individual drug-drug, food, or supplement interactions. However, because it is part of a multi-drug chemotherapy regimen, your oncology pharmacist and care team should review all medications — prescription, over-the-counter, and supplements — before and during treatment.

  • Rylaze is used alongside other chemotherapy drugs; the full regimen should be reviewed by your oncology team for potential combined toxicities
  • Hormonal contraceptives may be less reliable during treatment — non-hormonal birth control is recommended

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

📋Before taking it
  • Do not use Rylaze if you have had a serious allergic reaction (including anaphylaxis) to Erwinia asparaginase in the past
  • Do not use if you have a history of serious pancreatitis, serious blood clots, or serious bleeding events caused by asparaginase therapy
  • Do not use if you have severe liver (hepatic) impairment
  • Tell your doctor if you are pregnant — Rylaze can cause fetal harm based on animal studies; pregnancy testing is recommended before starting treatment
  • Use effective non-hormonal contraception during treatment and for 3 months after the last dose if you are able to become pregnant
  • Do not breastfeed during treatment or for 1 week after the last dose
  • Rylaze is approved for patients as young as 1 month of age; it has not been studied in infants younger than 1 month
  • There is limited safety data in adults 65 years of age and older
  • The effects of kidney or liver impairment on how your body handles Rylaze have not been fully studied; severe liver impairment is a contraindication
📡Pharmacodynamics — effects in the body

The relationship between Rylaze exposure levels and its pharmacodynamic response (how it affects the body over time) has not been fully characterized. The drug's therapeutic effect is based on depletion of asparagine from the plasma (blood), which is necessary for leukemic cell survival. The precise exposure-response relationship and the time course of this response remain under study.

🔬Pharmacokinetics — how your body processes it

After an intramuscular injection of Rylaze, peak drug activity in the blood is reached at a median of about 12 hours. The drug's apparent half-life — the time it takes for the body to clear half of it — is approximately 16 hours, and it is expected to be broken down into small peptides through normal protein-clearing (catabolic) pathways. Absorption from the muscle is about 37% in healthy subjects. There were no clinically significant differences in how the drug is processed based on age (1.4 to 25 years), weight, or sex when the dose is adjusted for body surface area; however, Black or African American patients showed approximately 29% lower clearance, which may result in higher drug exposure. The effects of kidney or liver impairment have not been formally studied.

📦How to store it

Store RYLAZE vials refrigerated at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light.

📄 Written from Asparaginase Erwinia Chrysanthemi Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →

🩺 Pharmacist Counseling Corner

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

Why am I getting Rylaze instead of the asparaginase I was on before?
Rylaze is specifically designed for patients who have developed an allergic reaction to asparaginase products made from E. coli bacteria — the type most commonly used first in leukemia treatment. Rylaze comes from a different bacterial source called Erwinia chrysanthemi, so it can often be used safely when the other form can't. It works the same way but has a different protein structure that your immune system is less likely to react to.
What should I watch out for after getting my injection?
The most important things to watch for are signs of a serious allergic reaction — things like hives, swelling, trouble breathing, or feeling faint — which can happen during or after the injection. Also call your care team right away if you have severe stomach pain (which could mean pancreatitis), unusual or heavy bleeding, signs of a blood clot like leg swelling or chest pain, or yellowing of your skin or eyes. These reactions are serious but your care team monitors for them closely at every visit.
Will I feel sick from this medication?
Many patients do experience side effects like nausea, fatigue, muscle aches, headache, and decreased appetite — most of these are manageable and your care team can help. Abnormal liver tests are also common and are monitored regularly. Because Rylaze is given alongside other chemotherapy drugs, it can be hard to know which drug is causing a specific side effect, but your oncology team tracks everything and adjusts your treatment plan as needed.
Is it safe to use Rylaze if I'm pregnant or trying to get pregnant?
Rylaze can harm an unborn baby — animal studies showed serious effects including birth defects and fetal loss even at doses lower than those used in people. If you could become pregnant, your doctor will recommend a pregnancy test before you start treatment and will advise you to use effective non-hormonal birth control during treatment and for 3 months after your last dose. If you become pregnant during treatment, talk to your doctor right away.
Can I breastfeed while on Rylaze?
No — it's not safe to breastfeed while taking Rylaze. It's not known whether the drug passes into breast milk, but because of the potential for serious harm to a nursing infant, you should avoid breastfeeding during treatment and for 1 week after your last dose. Talk to your care team if you have concerns about this.
How long will I be on Rylaze, and how often do I have to come in for injections?
That depends on your overall chemotherapy plan and which long-acting asparaginase product Rylaze is replacing. You'll receive injections either every 48 hours or on a Monday, Wednesday, and Friday schedule — your oncology team will map out exactly how many doses you need for each phase of your treatment. The injections are always given in the clinic so your team can monitor you for any reactions right away.
Is Asparaginase Erwinia Chrysanthemi Injection available over the counter?
Asparaginase Erwinia Chrysanthemi Injection is dispensed by prescription according to its FDA labeling, so it isn't sold over the counter. Your prescriber and pharmacist will determine if it's appropriate for you.
When was Asparaginase Erwinia Chrysanthemi Injection first available?
Asparaginase Erwinia Chrysanthemi Injection has been available in the United States since at least 2021, based on FDA approval history (Drugs@FDA) and product marketing records.
Who makes Asparaginase Erwinia Chrysanthemi Injection?
Asparaginase Erwinia Chrysanthemi Injection is supplied by 2 manufacturers listed in the FDA NDC Directory, including Jazz Pharmaceuticals, Inc., Patheon Manufacturing Services LLC.

💬 Answers drafted from Asparaginase Erwinia Chrysanthemi Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →

🧰 Keep exploring

💊 How Asparaginase Erwinia Chrysanthemi Injection comes

Asparaginase Erwinia Chrysanthemi 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.

Injection

By injection · Into a muscle
Brands Rylaze
How this form is used
What it may be used for
  • Rylaze is used as part of a multi-agent chemotherapy regimen to treat acute lymphoblastic leukemia (ALL) in adults and pediatric patients 1 month or older who have developed hypersensitivity to E. coli-derived asparaginase
  • Rylaze is used as part of a multi-agent chemotherapy regimen to treat lymphoblastic lymphoma (LBL) in adults and pediatric patients 1 month or older who have developed hypersensitivity to E. coli-derived asparaginase
  • Rylaze serves as a replacement for long-acting asparaginase products (such as pegaspargase or calaspargase pegol) when those can no longer be used due to allergic reactions
Important instructions
  • Rylaze is administered by intramuscular injection only; the intravenous (IV) route is not approved
  • Rylaze injection sites should be rotated and should never be in areas that are scarred, reddened, inflamed, or swollen
  • Rylaze can be given on two schedules — every 48 hours, or on a Monday/Wednesday/Friday schedule — as directed by your oncology team
  • Rylaze must be given in a medical setting with emergency equipment available to treat serious allergic reactions; patients receive premedication (acetaminophen, antihistamines) 30–60 minutes before each dose
Available strengths 1 strength
4 FDA-listed product records

📊 Asparaginase Erwinia Chrysanthemi Injection across the U.S. market

How Asparaginase Erwinia Chrysanthemi 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
Dose forms
2
Manufacturers
1
Brand names
4
FDA-listed product records
2021
First marketed
Jazz Pharmaceuticals, Inc.75%
Patheon Manufacturing Services LLC25%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

📈 How widely Asparaginase Erwinia Chrysanthemi Injection is used

A general measure of how commonly Asparaginase Erwinia Chrysanthemi Injection is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Asparaginase Erwinia Chrysanthemi Injection is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

922
Medicaid prescriptions filled (Q1–Q4 2025)
$7.5M gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Asparaginase Erwinia Chrysanthemi Injection prescribed? Of the 1,594 medications we measure, Asparaginase Erwinia Chrysanthemi Injection ranks #1,295 by Medicaid prescriptions — more than 19% of them.

Where Asparaginase Erwinia Chrysanthemi Injection ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Asparaginase Erwinia Chrysanthemi Injection, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 1 of 2 listed Asparaginase Erwinia Chrysanthemi Injection NDCs with Medicaid activity.

🔍 Compare Asparaginase Erwinia Chrysanthemi Injection products

A representative set of FDA-listed product records for Asparaginase Erwinia Chrysanthemi 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
20 mg/mL Intramuscular Jazz Pharmaceuticals, Inc. × 3 listings BLA View NDC →
20 mg/mL Patheon Manufacturing Services LLC DRUG FOR FURTHER PROCESSING View NDC →

Showing 4 of 4 products — FDA National Drug Code Directory. See every product, package size and price: browse all 4 Asparaginase Erwinia Chrysanthemi Injection NDCs →

🏷️ Sold under these brand names

Erwinaze Rylaze

🏭 Manufacturers & labelers

Jazz Pharmaceuticals, Inc. 3 Patheon Manufacturing Services LLC 1

RxNorm drug class

Asparaginase Erwinia Chrysanthemi 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.

🔬 Where this comes from

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 Jul 1, 2025
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Asparaginase Erwinia Chrysanthemi 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 Asparaginase Erwinia Chrysanthemi Injection after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
1
NDC products indexed
4
Distinct labelers/manufacturers represented
2
Linked representative label
Jazz Pharmaceuticals, Inc.
Linked label effective
Jul 1, 2025
Composite sections available
19
Linked SPL Set ID
857e53aa-1098-4dad-b654-0276cdd43e03
Linked SPL Document ID
cca29ff5-d000-43da-b64a-c65816a8a9c4
Open the linked representative label on DailyMed ↗

How we combine label and product data

HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 1 FDA-filed SPL label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.

Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Jazz Pharmaceuticals, Inc. is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.

This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.