TheraRadar
Data updated: May 26, 2026

ELSPAR (asparaginase)

Trial Activity: Expansion 4 active trials
Oncology Approved 1978-01-10

Rylaze is an asparagine-specific enzyme indicated for use as a component of a multi-agent chemotherapeutic regimen. It is approved for the treatment of adult and pediatric patients, aged one month and older, with acute lymphoblastic leukemia (ALL) or lymphoblastic lymphoma (LBL). This medication serves as a therapeutic option for patients who have developed hypersensitivity to E. coli-derived asparaginase.

Source: FDA Label • Merck • Asparagine-specific Enzyme

How ELSPAR Works

This drug is a recombinant enzyme that catalyzes the conversion of the amino acid L-asparagine into aspartic acid and ammonia. This action results in the depletion of plasma asparagine, which leukemic cells require for survival. Because these malignant cells have low expression of asparagine synthetase, they lack the ability to synthesize their own asparagine and die when the exogenous supply is removed.

Development Insights

National Cancer Institute (NCI) conducting 3 trials (33%)
26 indications explored (Broad Platform)
acute lymphoblastic leukemia (4 trials)
acute myeloid leukemia (2 trials)
recurrent b acute lymphoblastic leukemia (1 trials)
1
Indication
--
Phase 3 Trials
48
Years on Market

Details

Status
Prescription
First Approved
1978-01-10
Routes
N/A
Dosage Forms
VIAL

Companies

Active Ingredient: ASPARAGINASE

ELSPAR Approval History

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Original
New Indication
New Form
Label Update
7 FDA actions from 1978 to 2013
Jul 2013 SUPPL
Label · Labeling
May 2010 SUPPL
Label · Labeling
Mar 2007 SUPPL
Label · Labeling

What ELSPAR Treats

3 indications

ELSPAR is approved for 3 conditions since its original approval in 1978. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Acute Lymphoblastic Leukemia
  • Lymphoblastic Lymphoma
  • Hypersensitivity
Source: FDA Label

ELSPAR Competitive Set

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Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

What's emerging in ELSPAR's indications

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Phase 3 candidates targeting molecules with no FDA-approved drug, in indications ELSPAR treats. First-in-class if their pivotal trials read out positive.

Drugs Similar to ELSPAR

3 of 19

FDA-approved drugs for similar conditions. Compare mechanisms and indications to understand treatment alternatives.

RYLAZE
ASPARAGINASE ERWINIA CHRYSANTHEMI (RECOMBINANT)-RYWN
3 shared
JAZZ PHARMS
Shared indications:
Acute Lymphoblastic LeukemiaLymphoblastic LymphomaHypersensitivity
ONCASPAR
PEGASPARGASE
2 shared
SIGMA TAU
Shared indications:
ASPARLAS
CALASPARGASE PEGOL-MKNL
1 shared
SERVIER PHARMA LLC
Shared indications:
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Clinical Trial Registry

9 trials
Trial Sponsor ID Phase Status Title
NCT02101853 results posted NCI-2014-00631 NCI-2014-00631, s15-00970 Ph 3 active not recruiting Blinatumomab in Treating Younger Patients With Relapsed B-cell Acute Lymphoblastic Leukemia
NCT01371981 results posted NCI-2011-02670 NCI-2011-02670, CDR0000701850 Ph 3 active not recruiting Bortezomib and Sorafenib Tosylate in Treating Patients With Newly Diagnosed Acute Myeloid Leukemia
NCT02521493 results posted AAML1531 NCI-2015-00324, AAML1531 Ph 3 active not recruiting Response-Based Chemotherapy in Treating Newly Diagnosed Acute Myeloid Leukemia or Myelodysplastic Syndrome in Younger Patients With Down Syndrome
NCT03817320 results posted T2017-002 Ph 1, Ph 2 active not recruiting PO Ixazomib in Combination With Chemotherapy for Childhood Relapsed or Refractory Acute Lymphoblastic Leukemia and Lymphoblastic Lymphoma
NCT00557193 results posted AALL0631 NCI-2009-00313, CDR0000573996 Ph 3 completed Combination Chemotherapy With or Without Lestaurtinib in Treating Younger Patients With Newly Diagnosed Acute Lymphoblastic Leukemia
NCT03668392 ALL2518 ALL2518 2018-003517-17 Ph 2 terminated Asparaginase Activity Monitoring (AAM) in Adult Patients With Acute Lymphoblastic Leukemia (ALL)
NCT00720109 results posted NCI-2009-00312 NCI-2009-00312, AALL0622 Ph 2, Ph 3 completed Dasatinib and Combination Chemotherapy in Treating Young Patients With Newly Diagnosed Acute Lymphoblastic Leukemia
NCT02538926 9459 NCI-2015-01402, CC9459 Ph 2 withdrawn Etoposide, Prednisone, Vincristine Sulfate, Cyclophosphamide, and Doxorubicin Hydrochloride With Asparaginase in Treating Patients With Acute Lymphoblastic Leukemia or Lymphoblastic Lymphoma
NCT00784017 MC-ASP.5/ALL EudraCT number 2006-003180-31 Ph 3 completed Comparative Efficacy and Safety of Two Asparaginase Preparations in Children With Previously Untreated Acute Lymphoblastic Leukaemia
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Active Pipeline

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Ongoing clinical trials by development phase

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Key Completed Trials

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Completed studies with published results, ranked by significance

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Trial Timeline

Full development history with FDA approval milestones

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Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

ELSPAR FDA Label Details

Indications & Usage

FDA Label (PDF)

ELSPAR is indicated for the treatment of Acute Lymphoblastic Leukemia; Lymphoblastic Lymphoma; Hypersensitivity.

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Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.

How We Calculate These Metrics

Trial Activity Stage

Measures the current development activity pattern based on trial phases, status, and trends. Important: This measures R&D activity, not commercial lifecycle.

Trial statuses: "Active" means recruiting or ongoing. "Completed" means reached planned endpoint. "Terminated" means stopped early—often due to safety, efficacy, or business reasons.

  • Growth: High proportion of early-phase trials (Phase 1/2), active development
  • Expansion: Significant Phase 3 activity, approaching or pursuing approvals
  • Mature: Substantial Phase 4 post-marketing studies
  • Stable: Mixed phase distribution, steady development
  • Declining: Low active trial ratio, reduced R&D investment