CLINICAL TRIALS PROFILE FOR NAPRELAN

All Clinical Trials for NAPRELAN

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00778193 ↗	Effect of Naproxen, Aspirin, Celecoxib, or Clopidogrel on the Healing of Stomach and Intestinal Ulcers	Completed	Research Associates of New York, LLP	Phase 4	2007-10-01	Gastroduodenal ulcers are extremely common in the community today. Though much has been written and observed concerning how ulcers form, not much has been described in the human model concerning how these ulcers heal. As numerous patients already suffer from gastrointestinal ulcers, further clarification of ulcer healing would be valuable in the treatment and management of these patients. The goal of this study is to investigate the effects of naproxen, aspirin, celecoxib, and clopidogrel on biopsy-induced gastroduodenal lesions in order to elucidate the mechanisms of ulcer healing. This single site, single-blind, randomized, placebo-controlled, one-week prospective study will examine ulcer healing through endoscopic, immunohistologic, and molecular PCR modalities.
NCT00969449 ↗	Pharmacokinetics Study Comparing Naproxen Sodium Extended Release and Naprelan	Completed	Bayer	Phase 1	2009-04-01	To compare the pharmacokinetic profile of the proposed extended- release tablet of naproxen sodium 660 mg relative to two tablets of Naprelan 500 mg following single dose administration for 36 hours under fasted conditions
NCT01442428 ↗	Paradoxical Tuberculosis Immune Reconstitution Inflammatory Syndrome (TB-IRIS) Treatment Trial	Withdrawn	Minnesota Medical Foundation	Phase 2/Phase 3	2014-01-01	Tuberculosis is the most common opportunistic infection (OI) in HIV-infected persons worldwide, including in South East Asia. Significant numbers of patients experience tuberculosis-related paradoxical immune reconstitution inflammatory syndrome (TB-IRIS) after ART initiation, yet the optimal treatment of TB-IRIS is unknown. A recent randomized-controlled trial showed the benefit of prednisone over placebo in reduction of days of hospitalization and invasive procedures. The investigators hypothesize that nonsteroidal anti-inflammatory drugs (NSAIDs) are as effective as corticosteroids for treatment of non-life threatening TB-IRIS in HIV-infected patients and hypothesize that adjunctive treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (Statins) may improve the outcomes. This is a randomized controlled trial with a 2x2 factorial design to test the relative benefit of corticosteroids, NSAIDS, and Statins for the symptomatic and immunologic control of TB-IRIS.
NCT01442428 ↗	Paradoxical Tuberculosis Immune Reconstitution Inflammatory Syndrome (TB-IRIS) Treatment Trial	Withdrawn	Pfizer	Phase 2/Phase 3	2014-01-01	Tuberculosis is the most common opportunistic infection (OI) in HIV-infected persons worldwide, including in South East Asia. Significant numbers of patients experience tuberculosis-related paradoxical immune reconstitution inflammatory syndrome (TB-IRIS) after ART initiation, yet the optimal treatment of TB-IRIS is unknown. A recent randomized-controlled trial showed the benefit of prednisone over placebo in reduction of days of hospitalization and invasive procedures. The investigators hypothesize that nonsteroidal anti-inflammatory drugs (NSAIDs) are as effective as corticosteroids for treatment of non-life threatening TB-IRIS in HIV-infected patients and hypothesize that adjunctive treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (Statins) may improve the outcomes. This is a randomized controlled trial with a 2x2 factorial design to test the relative benefit of corticosteroids, NSAIDS, and Statins for the symptomatic and immunologic control of TB-IRIS.
NCT01442428 ↗	Paradoxical Tuberculosis Immune Reconstitution Inflammatory Syndrome (TB-IRIS) Treatment Trial	Withdrawn	University of Minnesota	Phase 2/Phase 3	2014-01-01	Tuberculosis is the most common opportunistic infection (OI) in HIV-infected persons worldwide, including in South East Asia. Significant numbers of patients experience tuberculosis-related paradoxical immune reconstitution inflammatory syndrome (TB-IRIS) after ART initiation, yet the optimal treatment of TB-IRIS is unknown. A recent randomized-controlled trial showed the benefit of prednisone over placebo in reduction of days of hospitalization and invasive procedures. The investigators hypothesize that nonsteroidal anti-inflammatory drugs (NSAIDs) are as effective as corticosteroids for treatment of non-life threatening TB-IRIS in HIV-infected patients and hypothesize that adjunctive treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (Statins) may improve the outcomes. This is a randomized controlled trial with a 2x2 factorial design to test the relative benefit of corticosteroids, NSAIDS, and Statins for the symptomatic and immunologic control of TB-IRIS.
NCT01442428 ↗	Paradoxical Tuberculosis Immune Reconstitution Inflammatory Syndrome (TB-IRIS) Treatment Trial	Withdrawn	University of Minnesota - Clinical and Translational Science Institute	Phase 2/Phase 3	2014-01-01	Tuberculosis is the most common opportunistic infection (OI) in HIV-infected persons worldwide, including in South East Asia. Significant numbers of patients experience tuberculosis-related paradoxical immune reconstitution inflammatory syndrome (TB-IRIS) after ART initiation, yet the optimal treatment of TB-IRIS is unknown. A recent randomized-controlled trial showed the benefit of prednisone over placebo in reduction of days of hospitalization and invasive procedures. The investigators hypothesize that nonsteroidal anti-inflammatory drugs (NSAIDs) are as effective as corticosteroids for treatment of non-life threatening TB-IRIS in HIV-infected patients and hypothesize that adjunctive treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (Statins) may improve the outcomes. This is a randomized controlled trial with a 2x2 factorial design to test the relative benefit of corticosteroids, NSAIDS, and Statins for the symptomatic and immunologic control of TB-IRIS.
NCT01951105 ↗	Effect of L-dopa In Subacute Back Pain Population	Completed	National Institute of Dental and Craniofacial Research (NIDCR)	Phase 4	2015-02-24	This study aims to determine if early treatment with Carbidopa/Levodopa and Naproxen in individuals with sub-acute back pain (SBP) is associated with changes in blocking transition to chronic back pain (CBP).

Clinical Trial Conditions for NAPRELAN

Condition Name

Condition Name for NAPRELAN
Intervention	Trials
Chronic Low Back Pain	2
Acute Pain	2
Bunionectomy	1
Gastroduodenal Ulcer	1

Condition MeSH

Condition MeSH for NAPRELAN
Intervention	Trials
Back Pain	3
Acute Pain	2
Low Back Pain	2
Peptic Ulcer	1

Clinical Trial Locations for NAPRELAN

Trials by Country

Trials by Country for NAPRELAN
Location	Trials
United States	6
Thailand	1

Trials by US State

Trials by US State for NAPRELAN
Location	Trials
Illinois	4
Texas	1
New York	1

Clinical Trial Progress for NAPRELAN

Clinical Trial Phase

Clinical Trial Phase for NAPRELAN
Clinical Trial Phase	Trials
Phase 4	4
Phase 2/Phase 3	1
Phase 2	2

Clinical Trial Status

Clinical Trial Status for NAPRELAN
Clinical Trial Phase	Trials
Completed	4
Withdrawn	2
Not yet recruiting	1

Clinical Trial Sponsors for NAPRELAN

Sponsor Name

Sponsor Name for NAPRELAN
Sponsor	Trials
National Institutes of Health (NIH)	5
Northwestern University	4
National Institute of Dental and Craniofacial Research (NIDCR)	2

Sponsor Type

Sponsor Type for NAPRELAN
Sponsor	Trials
Other	10
NIH	9
Industry	2

Naprelan (naproxen sodium) Clinical Trials Update, Market Analysis, and Exclusivity/Generic Entry Outlook

Last updated: July 30, 2026

Naprelan is an extended-release (ER) naproxen sodium product marketed for osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and related pain conditions. Its IP and regulatory status are dominated by late-dated formulation and composition-of-matter-style claims tied to ER naproxen technology, plus ongoing regulatory maintenance that controls manufacturing and label updates. From a business-risk perspective, Naprelan’s near-term market outlook is driven by generic penetration, payer substitution, and brand-level contracting rather than new clinical readouts.

What clinical trials update exists for Naprelan (naproxen sodium) ER?

Clinical-trial pipeline signal No active, new late-stage (Phase 3) clinical program is required for continued marketing of Naprelan, because it is an established small-molecule product. Commercial updates typically surface through label supplements, bioequivalence submissions for generic/authorized brands, and formulation/manufacturing changes that do not map to a “clinical trials update” narrative in the way biologics or new chemical entities do.

Where Naprelan trial activity usually shows up

1. Bioequivalence and formulation bridging
   • Generic sponsors file BE studies rather than efficacy Phase 3 trials for ER naproxen sodium.
2. Analytical comparability
   • Post-approval changes (site, scale, excipients, coating or release-system parameters) use comparability packages.
3. Safety/real-world studies
   • Postmarketing pharmacoepidemiology generally evaluates NSAID class risks (GI bleeding, CV risk) rather than product-specific efficacy.

Practical takeaway for R&D and licensing For Naprelan, “clinical trials update” activity that matters commercially is usually regulatory and BE-driven, not efficacy re-trials. The investment case for a challenger is more about formulation robustness and regulatory strategy than about proving new clinical endpoints.

What endpoints matter most in Naprelan-related studies?

• Pain and function in osteoarthritis and rheumatoid arthritis (pain scores, patient global assessment, NSAID rescue use).
• Safety outcomes for NSAIDs as a class:
  • GI events and bleeding signals
  • Cardiovascular events and thrombotic risk
  • Renal impairment and blood pressure effects

Does Naprelan have new comparative trials versus other NSAIDs?

For established ER naproxen products, comparative evidence typically comes from:

• Class-wide NSAID literature
• Indirect comparisons rather than head-to-head ER naproxen sodium Phase 3 programs

What is the current market size and demand profile for Naprelan (naproxen sodium) ER?

Market context Naprelan competes in the broader NSAID analgesic market, with substitution pressure from:

• Generic naproxen ER formulations
• Alternative NSAIDs (ibuprofen ER, diclofenac ER, meloxicam, celecoxib where appropriate)
• Formulary positioning and step therapy

Demand drivers

1. Formulary access and tier placement
   • ER NSAIDs are payer-sensitive; brand retention depends on contract terms.
2. Dosing convenience
   • ER reduces dosing frequency versus immediate-release naproxen sodium.
3. Switching dynamics
   • Patients stable on one ER NSAID can be “locked in” for periods if adverse effects are minimal, but payer-driven switches occur when contracts change.

How does Naprelan compare with other ER NSAIDs on demand?

• ER naproxen products typically occupy a mid-to-lower branded premium once generics dominate.
• Competitive advantage for any remaining brand is contract-specific and prescriber-specific rather than based on distinct clinical superiority.

How does patent exclusivity affect Naprelan market duration?

Core exclusivity reality Naprelan, as an older NSAID brand, is beyond primary newness. The commercial lifespan is therefore governed by:

• Remaining patent claims tied to ER technology (if any are still in force in relevant jurisdictions)
• Regulatory exclusivities that could attach to labeling or changes (less common for established drugs)
• Practical enforceability against generic entry

When does Naprelan lose exclusivity?

Naprelan’s market exclusivity is expected to be driven by the expiration of ER naproxen-related patents and the exhaustion of regulatory exclusivity periods. For an older small-molecule brand, generic entry risk is typically highest once key formulation/process claims expire, and commercial erosion follows shortly thereafter.

What patent estate protects Naprelan (naproxen sodium) ER?

For established ER NSAIDs, patent coverage usually clusters into:

• Formulation claims (release mechanisms, ratios of polymers/excipients)
• Composition claims (naproxen salt/excipient combinations for ER)
• Manufacturing/process claims for coating or granulation parameters

From a diligence standpoint, an investor or licensee screens:

• Whether any ER-specific formulation patents remain in the US for Naprelan’s dosage form
• Whether method-of-manufacture claims can be designed around without risking infringement

What is the Orange Book status of Naprelan?

Naprelan’s Orange Book status is the operational map for:

• Patent-listed products (active ingredient and dosage form)
• Expiration dates
• Any listed method-of-use, formulation, or process patents
• Whether there are recent changes in listed patents that can delay generic approvals

Business-use interpretation

• If Naprelan is fully surrounded by expired patents and no enforceable listed patents remain, Paragraph IV exposure drops and generic entry becomes schedule-driven by ANDA readiness.
• If Orange Book lists remaining patents, the next generic entrants face litigation or settlement risk.

Which companies sell Naprelan, and which generics compete most directly?

Brand and label Naprelan is marketed as naproxen sodium ER, with the main competitive set including other ER naproxen sodium products and generic ER equivalents.

Generic competition vector

• Generic manufacturers enter via ANDA with bioequivalence to the reference listed drug.
• Market share is won via:
  • Contract pricing
  • Coverage breadth
  • Pharmacy distribution terms
  • Substitution policies

What generic entry risks exist for Naprelan (Paragraph IV challenges)?

For established products, Paragraph IV litigation risk is strongest when:

• Orange Book lists at least one still-enforceable patent, and
• A generic applicant chooses to challenge that patent rather than file under a design-around.

Practical market consequence

• If Naprelan is free of enforceable listed patents (or has last-expiring patents already passed), ANDAs can launch with fewer patent-based barriers.
• If patents are active, generic launches depend on litigation timing and potential settlements.

What patent litigation affects Naprelan?

For older NSAID brands, the litigation footprint is generally:

• Historic and associated with formulation or process patents
• Resolved through settlements or expiration rather than ongoing trials that materially change market trajectory

Business impact lens

• Litigation history is used to forecast enforceability duration rather than to predict future clinical relevance.
• Any current litigation matters only if it affects the timing of generic approvals or triggers injunction leverage.

How strong is the patent estate for Naprelan (naproxen sodium) ER?

Strength is measured by enforceable “in-force” claims at the dosage form level For ER naproxen products, the practical strength of the estate tends to be limited by:

• Age of key filings
• Narrow claim scope around release technology or manufacturing parameters
• Design-around feasibility in small-molecule ER systems

Investor/legal diligence checklist (US)

• Identify the latest in-force Orange Book patents tied to ER Naprelan
• Determine whether those patents are formulation/process rather than broad composition claims
• Assess obviousness/design-around pathways for excipient/coating parameter changes

What formulations are protected by Naprelan patents?

ER naproxen sodium protection typically maps to:

• Specific polymeric release control systems
• Granulation and coating methodologies
• Excipient blends controlling drug release profile and dissolution criteria

Commercial implication Even if a generic company can produce naproxen sodium ER, infringement risk depends on whether release-control system parameters match the claimed ranges or equivalence language.

How does Naprelan compare with other naproxen ER products for competitive positioning?

What matters

• Dosing frequency and patient adherence profiles
• Cost and payer coverage
• Product-specific bioequivalence compliance for the ER profile

What usually does not

• Meaningful therapeutic differentiation in Phase 3 sense among ER naproxen brands once generics dominate.

What are the regulatory milestones and FDA status for Naprelan?

Naprelan’s FDA status is typically stable:

• Approved NDA/ANDA reference listing
• Postmarketing changes that do not require new efficacy trials
• Bioequivalence-based access for generics

Business relevance

• Regulatory change activity most often affects:
  • Manufacturing site qualification
  • Labeling changes
  • Approved strengths and dosage form descriptions
  • Patent update timing (Orange Book maintenance)

What market projection applies to Naprelan (naproxen sodium) ER over the next 3–7 years?

Projection framework Because Naprelan is a legacy branded ER NSAID, the market trajectory is mainly a function of:

• Generic penetration rate and share retention
• Payer contracting cycles
• Wholesale acquisition cost dynamics and conversion to generic-first formularies
• Any remaining brand protections (patents and settlements)

Base-case projection (commercial)

• Continued share erosion versus generic ER naproxen equivalents.
• Brand unit demand stabilizes only in markets where contracts preserve branded access or where patients remain on therapy long-term.

Bull-case (limited)

• Brand retention could improve if:
  • Remaining enforceable patent coverage delays certain generics
  • Payer contracts favor the brand for a period
  • Safety/label positioning supports continued preference in specific patient subgroups

Bear-case

• Faster share loss if:
  • Orange Book protections have already expired and additional generic entrants launch
  • Net pricing compresses due to competitive bids in pharmacy benefit contracts

Key takeaways

• Naprelan’s “clinical trials update” is not driven by new efficacy trials; it is primarily bioequivalence, regulatory maintenance, and postmarketing safety evidence for NSAIDs.
• Market performance is driven by payer substitution and generic penetration rather than therapeutic differentiation.
• Exclusivity and enforceability are the main swing factors for any residual branded share.
• Patent strength for established ER NSAIDs is typically narrower and design-aroundable, so generic entry timing often follows expiration schedules and settlement outcomes more than it follows clinical development milestones.

FAQs

1. What controls generic launch timing for Naprelan beyond patent expiration?
2. How do Orange Book formulation patents for ER naproxen sodium translate into ANDA infringement risk?
3. What bioequivalence study design elements matter for ER naproxen sodium products?
4. Which payer rules most often drive substitution from branded ER naproxen to generics?
5. What postmarketing safety signals most affect market access for NSAID ER products like Naprelan?

References

1. FDA. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. U.S. Food and Drug Administration. (Accessed 2026-07-30).