Last updated: August 1, 2026
Dalteparin sodium is a low-molecular-weight heparin marketed primarily as Fragmin by Pfizer. Its core U.S. exclusivity period has expired, and competition is driven by generic injectable products, hospital contracting, manufacturing reliability, and regulatory complexity rather than by active patent protection. Clinical development has shifted from broad approval expansion toward oncology-associated thrombosis, pediatric thrombosis, perioperative anticoagulation, and comparative effectiveness research.
What is dalteparin sodium used for?
Dalteparin sodium is an injectable anticoagulant derived from unfractionated heparin. It potentiates antithrombin-mediated inhibition of factor Xa and, to a lesser degree, thrombin. The drug is administered subcutaneously and is available in prefilled syringes and multidose vials.
The FDA-approved uses of Fragmin include:
| Indication |
U.S. regulatory status |
| Prophylaxis of deep-vein thrombosis after abdominal surgery |
Approved |
| Prophylaxis of DVT after hip-replacement surgery |
Approved |
| Prophylaxis of ischemic complications in unstable angina and non-Q-wave myocardial infarction |
Approved with aspirin |
| Extended treatment of symptomatic venous thromboembolism in patients with cancer |
Approved |
| Pediatric venous thromboembolism |
Not a broad original indication; pediatric use has been supported by clinical practice and subsequent labeling developments in selected jurisdictions |
The cancer-associated thrombosis indication is commercially important because dalteparin was one of the first anticoagulants supported by randomized evidence for extended treatment in patients with active malignancy. The CLOT study found lower recurrent venous thromboembolism with dalteparin than with oral vitamin K antagonist therapy, although major bleeding remained a clinically relevant risk (Lee et al., 2003).
What is the current FDA status of dalteparin sodium?
Dalteparin sodium was approved in the United States under the brand name Fragmin in 1994. Pfizer is the reference-product sponsor. The product is regulated as a prescription anticoagulant and is supplied as an injectable drug.
The main regulatory characteristics are:
| Attribute |
Status |
| Active ingredient |
Dalteparin sodium |
| Reference brand |
Fragmin |
| Original U.S. sponsor |
Pharmacia and predecessor entities; now Pfizer |
| FDA approval |
1994 |
| Dosage form |
Subcutaneous injection |
| Therapeutic class |
Low-molecular-weight heparin |
| Primary U.S. indications |
Surgical DVT prophylaxis, acute coronary syndrome, cancer-associated VTE |
| Prescription status |
Prescription-only |
| Regulatory pathway for competitors |
Abbreviated or hybrid pathways, subject to product-specific FDA requirements |
Low-molecular-weight heparins are chemically heterogeneous mixtures rather than single molecular entities. FDA approval of a competing product therefore requires more than ordinary small-molecule identity testing. Sponsors must address molecular-weight distribution, chain composition, anticoagulant activity, manufacturing controls, impurity profile, and immunogenic or clinical characteristics.
What clinical trials are evaluating dalteparin sodium?
Most dalteparin studies are completed post-approval trials rather than active pivotal registration programs. The clinical evidence base is concentrated in four areas.
Cancer-associated thrombosis
Dalteparin remains clinically relevant in patients with cancer-associated VTE, particularly when clinicians prefer a parenteral anticoagulant or when oral absorption, drug interactions, bleeding risk, or gastrointestinal disease complicate use of a direct oral anticoagulant.
The CLOT trial compared six months of dalteparin with oral anticoagulation in patients with cancer and acute VTE. Recurrent VTE was lower in the dalteparin group. The study established the drug as a benchmark for extended anticoagulation in oncology (Lee et al., 2003).
Later trials and guidelines have shifted attention toward apixaban, edoxaban, and rivaroxaban. These agents have reduced the growth potential of dalteparin in newly diagnosed cancer-associated thrombosis, although dalteparin retains a role in patients with high gastrointestinal bleeding risk, drug-interaction concerns, or a preference for an established injectable regimen.
Pediatric venous thromboembolism
Pediatric use has generated continued research because dosing depends on age, weight, renal function, and anti-factor Xa monitoring. Children may require dose adjustments that differ materially from adult regimens.
Clinical studies have examined:
- Initial treatment of pediatric DVT and pulmonary embolism
- Anti-factor Xa target attainment
- Dose requirements in infants and neonates
- Treatment duration
- Safety during cancer therapy
- Use in children with central venous catheters
The pediatric market is small in volume but clinically specialized. It is less exposed to direct oral anticoagulant competition in neonates and very young children, where injectable anticoagulation and monitoring remain important.
Perioperative and hospitalized-patient thromboprophylaxis
Dalteparin is used for prevention of hospital-associated VTE after surgery and in selected medical inpatients. Research has compared LMWH regimens with unfractionated heparin, mechanical prophylaxis, and newer anticoagulant strategies.
Clinical differentiation is limited. Hospital formulary decisions generally consider:
- Dosing frequency
- Renal clearance
- Reversal and monitoring requirements
- Heparin-induced thrombocytopenia risk
- Syringe and vial presentation
- Acquisition price
- Contracting terms
- Nursing administration burden
Acute coronary syndrome
Dalteparin has been studied in unstable angina and non-Q-wave myocardial infarction, commonly in combination with aspirin. Its role has declined as antiplatelet therapy, invasive management, and other anticoagulant strategies have changed.
How strong is the dalteparin sodium patent estate?
The original composition, manufacturing, and use patents for dalteparin sodium were filed decades ago. The principal U.S. patent estate has expired or reached the end of its enforceable term. Commercial risk therefore comes primarily from regulatory and manufacturing barriers, not from a blocking patent portfolio.
What patents protect Fragmin?
Fragmin’s original protection related to:
- Low-molecular-weight heparin compositions
- Fractionation and depolymerization methods
- Anticoagulant use
- Formulations and injectable presentations
- Manufacturing specifications
Those rights were developed during the original commercialization period and are no longer expected to provide meaningful U.S. market exclusivity. Later patents covering specific formulations, packaging, or manufacturing improvements would require a product-specific patent search and Orange Book review.
What is the Orange Book status of dalteparin?
The Orange Book is relevant to FDA-approved drug products and listed patents. Dalteparin’s practical U.S. market position is consistent with an off-patent injectable product. No active, broad U.S. composition-of-matter exclusivity is generally associated with dalteparin sodium.
An abbreviated new drug application sponsor would still need to address any listed patents, exclusivity codes, labeling differences, and FDA requirements applicable to a complex LMWH product. The absence of broad patent protection does not eliminate the possibility of regulatory litigation or product-specific patent disputes.
When did dalteparin sodium lose exclusivity?
Dalteparin lost meaningful U.S. commercial exclusivity after expiration of its original patent and regulatory protection period. The product has been marketed for roughly three decades, and its current competitive position is post-exclusivity.
| Exclusivity category |
Commercial assessment |
| Original compound protection |
Expired |
| Original use patents |
Expired or commercially exhausted |
| FDA new-drug exclusivity |
Expired |
| Orphan-drug exclusivity |
Not the principal commercial protection |
| Pediatric exclusivity |
Any historical extension would have expired |
| Current blocking patent risk |
Low at the active-ingredient level |
| Current market barrier |
Complex manufacturing and FDA comparability requirements |
Are there Paragraph IV challenges to dalteparin sodium?
Paragraph IV litigation is less visible for dalteparin than for conventional oral drugs because generic LMWH development is technically difficult and the commercial opportunity is narrower.
A Paragraph IV certification would arise if an ANDA sponsor asserted that a listed patent was invalid, unenforceable, or not infringed. Because the core dalteparin patents are old, a modern entrant would be more likely to confront:
- FDA product-specific bioequivalence requirements
- Manufacturing comparability
- Reference-product availability
- Anti-Xa and anti-IIa activity testing
- Molecular-weight distribution requirements
- Potential clinical or immunogenicity questions
- Hospital purchasing contracts
The absence of major current Paragraph IV litigation does not indicate a protected market. It more likely reflects the limited economics and technical burden of entering the LMWH category.
What generic entry risks exist for dalteparin sodium?
Generic entry risk is moderate from a technical standpoint and high from an IP standpoint.
High IP risk to the brand
The core patent estate is old. Pfizer cannot rely on an active compound patent to prevent competition. Brand pricing is exposed to generic substitution, hospital tenders, and formulary pressure.
Moderate regulatory risk to generic entrants
Dalteparin is not a simple small molecule. A competing sponsor must establish sufficient sameness despite the drug’s heterogeneous polysaccharide structure. This creates a meaningful barrier to entry but does not preserve traditional patent-based exclusivity.
High commercial pressure in institutional channels
Hospitals can substitute among dalteparin, enoxaparin, unfractionated heparin, and, in some indications, direct oral anticoagulants. Contracts are often awarded on price, supply continuity, and overall anticoagulation portfolio economics.
How does dalteparin compare with competing anticoagulants?
| Product |
Main competitive advantage |
Main limitation |
| Dalteparin |
Long clinical history; cancer-associated thrombosis evidence; established LMWH dosing |
Injection, cost versus heparin, renal and bleeding considerations |
| Enoxaparin |
Broad adoption, extensive generic supply, strong hospital familiarity |
Injection; renal dosing concerns |
| Unfractionated heparin |
Low acquisition cost; rapid titration and reversibility |
IV monitoring; variable response; more labor intensive |
| Apixaban |
Oral administration; strong adoption in VTE and cancer-associated VTE |
Drug interactions and bleeding concerns |
| Rivaroxaban |
Oral dosing and broad VTE use |
Gastrointestinal bleeding and drug-interaction considerations |
| Edoxaban |
Oral treatment option after initial parenteral therapy |
Requires initial anticoagulant lead-in |
| Fondaparinux |
Once-daily injection; low HIT cross-reactivity |
Renal restrictions and limited use in some settings |
Dalteparin’s strongest competitive position is in specialized oncology and pediatric settings. Its weakest position is routine prophylaxis where generic enoxaparin or unfractionated heparin can meet clinical requirements at lower cost.
What is the market outlook for dalteparin sodium through 2030?
Public market reports differ widely because some count only branded Fragmin, while others include generic dalteparin and the broader LMWH market. A precise standalone global forecast is therefore unreliable. The more defensible projection is scenario-based.
Base-case projection
Through 2030, dalteparin revenue is likely to remain flat to modestly declining in mature markets. Growth in cancer incidence and ongoing VTE treatment demand should offset part of the erosion caused by generic competition and substitution with oral anticoagulants.
Downside scenario
Revenue declines at a mid-single-digit annual rate if:
- Generic dalteparin supply expands
- Oral anticoagulants take additional oncology share
- Pfizer reduces commercial investment
- Hospitals consolidate anticoagulant purchasing
- Manufacturing interruptions affect brand availability
Upside scenario
Revenue is stable or modestly higher if:
- Cancer-associated thrombosis remains an injectable niche
- Pediatric and high-bleeding-risk patients favor LMWH
- Supply constraints affect competing enoxaparin products
- New clinical data support selected oncology or perioperative uses
- Emerging-market access expands
| Market driver through 2030 |
Expected effect |
| Rising cancer incidence |
Positive |
| Direct oral anticoagulant adoption |
Negative |
| Generic LMWH competition |
Negative |
| Hospital VTE prophylaxis demand |
Stable to positive |
| Pediatric anticoagulation |
Small positive |
| Manufacturing complexity |
Limits new entrants |
| Price-based procurement |
Negative for branded Fragmin |
| Product shortages among competitors |
Intermittent positive |
Dalteparin is unlikely to return to high-growth status. Its commercial value is better characterized as a durable specialty anticoagulant franchise with declining brand power and persistent clinical utility.
What manufacturing and intellectual-property barriers affect dalteparin?
The central barrier is process control. Dalteparin production requires consistent control of depolymerization, molecular-weight distribution, sulfation pattern, chain composition, and anticoagulant activity.
Manufacturing risks include:
- Batch-to-batch heterogeneity
- Starting-material variability
- Animal-source supply controls
- Viral and transmissible-agent controls
- Impurity characterization
- Anti-Xa and anti-IIa assay reproducibility
- Scale-up validation
- Stability of prefilled syringes and multidose presentations
These factors can delay approval even when the underlying patents have expired. They also create supply-chain value for established manufacturers with validated heparin sourcing and regulatory history.
What litigation and settlement issues affect dalteparin?
There is no widely reported, active U.S. patent litigation campaign comparable to those involving branded oral anticoagulants or high-value biologics. The primary legal exposures are more likely to involve:
- ANDA certifications
- Product-specific formulation patents
- Manufacturing patents
- FDA approval timing
- Labeling disputes
- Supply and procurement contracts
- Product-liability claims involving bleeding or heparin-induced thrombocytopenia
A brand-generic settlement would have limited strategic value unless a new patent covering a commercially important formulation or manufacturing process were asserted. The aged core estate reduces the likelihood of a settlement materially delaying generic entry.
Key Takeaways
- Dalteparin sodium is an established LMWH marketed as Fragmin by Pfizer.
- FDA-approved uses include surgical DVT prophylaxis, acute coronary syndrome, and extended treatment of cancer-associated VTE.
- The CLOT trial remains the foundational evidence for dalteparin in cancer-associated thrombosis.
- Core U.S. patent and regulatory exclusivity has expired.
- Current commercial barriers are manufacturing complexity, FDA comparability requirements, and hospital contracting.
- Generic and therapeutic competition is strongest from enoxaparin, unfractionated heparin, and direct oral anticoagulants.
- The most defensible 2030 outlook is stable to modestly declining revenue, with specialized demand in oncology and pediatrics.
- Paragraph IV risk is limited by the aged patent estate, while regulatory and manufacturing risk remains material.
- Dalteparin is not a biosimilar in the conventional monoclonal-antibody sense, but its heterogeneous LMWH structure creates comparable complexity in demonstrating product sameness.
FAQs
Is dalteparin sodium still commercially relevant?
Yes. It remains relevant in cancer-associated thrombosis, pediatric anticoagulation, selected perioperative settings, and patients who are poor candidates for oral anticoagulants.
Is dalteparin interchangeable with enoxaparin?
No. Both are LMWHs, but they are not automatically interchangeable. Dosing, clinical evidence, labeling, and institutional protocols differ.
Does dalteparin require anti-factor Xa monitoring?
Routine monitoring is not required for most adults. Monitoring may be considered in children, pregnancy, severe renal impairment, obesity, underweight patients, or situations with unusual pharmacokinetic risk.
Can dalteparin cause heparin-induced thrombocytopenia?
Yes. The risk is lower than with unfractionated heparin but remains clinically important. A suspected case generally requires discontinuation and selection of a non-heparin anticoagulant.
Is dalteparin protected by orphan-drug exclusivity?
Orphan-drug exclusivity is not the principal current protection for dalteparin. Its commercial position is based on longstanding clinical use, manufacturing capability, regulatory history, and specialized demand.
References
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Food and Drug Administration. (2024). Fragmin (dalteparin sodium) prescribing information. U.S. Department of Health and Human Services.
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Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.
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Lee, A. Y. Y., Levine, M. N., Baker, R. I., Bowden, C., Kakkar, A. K., Prins, M., Rickles, F. R., et al. (2003). Low-molecular-weight heparin versus a coumarin for the prevention of recurrent venous thromboembolism in patients with cancer. New England Journal of Medicine, 349(2), 146-153.
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National Library of Medicine. (2025). ClinicalTrials.gov: Dalteparin sodium studies. U.S. National Library of Medicine.
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American Society of Hematology. (2021). American Society of Hematology 2021 guidelines for management of venous thromboembolism in patients with cancer. Blood Advances, 5(4), 927-974.
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European Medicines Agency. (2024). Guideline on the clinical investigation of medicinal products for the prophylaxis of venous thromboembolic risk in adults undergoing surgery. European Union.
