CLINICAL TRIALS PROFILE FOR DOXYCYCLINE

505(b)(2) Clinical Trials for DOXYCYCLINE

This table shows clinical trials for potential 505(b)(2) applications. See the next table for all clinical trials

Trial Type	Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
New Combination	NCT00694694 ↗	Azithromycin + Artesunate v Artemether-lumefantrine in Uncomplicated Malaria.	Completed	National Institute for Medical Research, Tanzania	Phase 3	2008-06-01	This trial sets out to determine whether the combination of azithromycin and artesunate (AZ+AS) is as good as the current standard treatment for uncomplicated malaria in Tanzania, artemether-lumefantrine (AL). There are two reasons this is important 1. there are only a limited range of drug combinations which work against malaria in this area of Tanzania 2. azithromycin has antimalarial properties, but is also a broad-spectrum antibiotic, so if the combination is an effective antimalarial it might have a place where there are no diagnostic facilities as syndromic treatment for fever. Artesunate and azithromycin have both been used alone or in combination with other drugs in children in Tanzania for many years, and are considered safe. There is trial evidence for the effectiveness of this combination in adults in Asia, as well as in-vitro (laboratory) evidence that it works against the malaria parasite. The trial randomizes children with non-severe malaria to the new combination AZ+AS or the standard care arm AL. The primary outcome is the parasitological failure rate by day 28- meaning do malaria parasites get cleared, and stay cleared for at least 28 days. Secondary outcomes include safety.
New Combination	NCT00694694 ↗	Azithromycin + Artesunate v Artemether-lumefantrine in Uncomplicated Malaria.	Completed	London School of Hygiene and Tropical Medicine	Phase 3	2008-06-01	This trial sets out to determine whether the combination of azithromycin and artesunate (AZ+AS) is as good as the current standard treatment for uncomplicated malaria in Tanzania, artemether-lumefantrine (AL). There are two reasons this is important 1. there are only a limited range of drug combinations which work against malaria in this area of Tanzania 2. azithromycin has antimalarial properties, but is also a broad-spectrum antibiotic, so if the combination is an effective antimalarial it might have a place where there are no diagnostic facilities as syndromic treatment for fever. Artesunate and azithromycin have both been used alone or in combination with other drugs in children in Tanzania for many years, and are considered safe. There is trial evidence for the effectiveness of this combination in adults in Asia, as well as in-vitro (laboratory) evidence that it works against the malaria parasite. The trial randomizes children with non-severe malaria to the new combination AZ+AS or the standard care arm AL. The primary outcome is the parasitological failure rate by day 28- meaning do malaria parasites get cleared, and stay cleared for at least 28 days. Secondary outcomes include safety.

All Clinical Trials for DOXYCYCLINE

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000403 ↗	Doxycycline and OA Progression	Completed	National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)	Phase 3	1996-09-01	This study will determine whether doxycycline decreases the severity or rate of progression of osteoarthritis (OA) in the knee. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most popular agents used to treat OA, but elderly women, in whom OA is especially common, are at greatest risk of developing serious side effects from NSAIDs. Our study targets overweight middle-aged women who have OA in one knee. Half of the 432 study participants will receive the treatment (doxycycline) and half will receive a placebo (inactive pill). Treatment with doxycycline (or placebo) will last 30 months, and participants and researchers will not know who is receiving doxycycline and who is receiving placebo until the end of the study. We will look for narrowing of the joint space in the knee that was not affected by OA at the start of the study. Joint space narrowing is a sign of OA. We will also use questionnaires to evaluate participants' symptoms and functioning.
NCT00000403 ↗	Doxycycline and OA Progression	Completed	National Institute on Aging (NIA)	Phase 3	1996-09-01	This study will determine whether doxycycline decreases the severity or rate of progression of osteoarthritis (OA) in the knee. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most popular agents used to treat OA, but elderly women, in whom OA is especially common, are at greatest risk of developing serious side effects from NSAIDs. Our study targets overweight middle-aged women who have OA in one knee. Half of the 432 study participants will receive the treatment (doxycycline) and half will receive a placebo (inactive pill). Treatment with doxycycline (or placebo) will last 30 months, and participants and researchers will not know who is receiving doxycycline and who is receiving placebo until the end of the study. We will look for narrowing of the joint space in the knee that was not affected by OA at the start of the study. Joint space narrowing is a sign of OA. We will also use questionnaires to evaluate participants' symptoms and functioning.
NCT00000403 ↗	Doxycycline and OA Progression	Completed	Indiana University	Phase 3	1996-09-01	This study will determine whether doxycycline decreases the severity or rate of progression of osteoarthritis (OA) in the knee. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most popular agents used to treat OA, but elderly women, in whom OA is especially common, are at greatest risk of developing serious side effects from NSAIDs. Our study targets overweight middle-aged women who have OA in one knee. Half of the 432 study participants will receive the treatment (doxycycline) and half will receive a placebo (inactive pill). Treatment with doxycycline (or placebo) will last 30 months, and participants and researchers will not know who is receiving doxycycline and who is receiving placebo until the end of the study. We will look for narrowing of the joint space in the knee that was not affected by OA at the start of the study. Joint space narrowing is a sign of OA. We will also use questionnaires to evaluate participants' symptoms and functioning.
NCT00000938 ↗	A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial of the Safety and Efficacy of Ceftriaxone and Doxycycline in the Treatment of Patients With Seronegative Chronic Lyme Disease	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 3	1969-12-31	Lyme disease is the most common tick-borne disease in the United States. It is caused by the spirochete Borrelia burgdorferi. It may exist in a chronic form and be the result of: 1) persistent infection by B. burgdorferi; 2) damage caused by the original infectious process; or 3) the presence of coinfection with another organism transmitted by Ixodes ticks. The purpose of this study is to determine the safety and effectiveness, in seronegative patients, of intensive antibiotic treatment in eliminating symptoms of Chronic Lyme Disease (CLD).
NCT00001101 ↗	A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial of the Safety and Efficacy of Ceftriaxone and Doxycycline in the Treatment of Patients With Seropositive Chronic Lyme Disease	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 3	1969-12-31	Lyme disease is the most common tick-borne disease in the United States. It is caused by the spirochete Borrelia burgdorferi. It may exist in a chronic form and be the result of: 1) active infection by B. burgdorferi; 2) damage caused by the original infectious process; or 3) the presence of co-infection with another organism transmitted by Ixodes ticks. The purpose of this study is to determine the safety and effectiveness, for seropositive patients, of intensive antibiotic treatment in eliminating symptoms of Chronic Lyme Disease (CLD).
NCT00002872 ↗	Bleomycin, Doxycycline, or Talc in Treating Patients With Malignant Pleural Effusions	Completed	National Cancer Institute (NCI)	Phase 3	1996-11-01	RATIONALE: Some drugs such as bleomycin or doxycycline, or other compounds like talc, may help to control fluid in the chest caused by cancer. It is not yet known if bleomycin, doxycycline, or talc is more effective in treating patients with malignant pleural effusions. PURPOSE: Randomized phase III trial to compare the effectiveness of bleomycin, doxycycline, or talc in treating patients with malignant pleural effusions.

Clinical Trial Conditions for DOXYCYCLINE

Condition Name

Condition Name for DOXYCYCLINE
Intervention	Trials
Acne Vulgaris	20
Rosacea	10
Syphilis	9
Acne	9

Condition MeSH

Condition MeSH for DOXYCYCLINE
Intervention	Trials
Infections	31
Acne Vulgaris	28
Infection	26
Communicable Diseases	25

Clinical Trial Locations for DOXYCYCLINE

Trials by Country

Trials by Country for DOXYCYCLINE
Location	Trials
United States	441
Canada	28
France	22
China	18
Egypt	13

Trials by US State

Trials by US State for DOXYCYCLINE
Location	Trials
California	36
New York	34
Texas	26
Pennsylvania	25
Florida	22

Clinical Trial Progress for DOXYCYCLINE

Clinical Trial Phase

Clinical Trial Phase for DOXYCYCLINE
Clinical Trial Phase	Trials
PHASE4	11
PHASE3	2
PHASE2	9

Clinical Trial Status

Clinical Trial Status for DOXYCYCLINE
Clinical Trial Phase	Trials
Completed	197
Recruiting	75
Unknown status	35

Clinical Trial Sponsors for DOXYCYCLINE

Sponsor Name

Sponsor Name for DOXYCYCLINE
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	16
University of Washington	10
University Medical Centre Ljubljana	10

Sponsor Type

Sponsor Type for DOXYCYCLINE
Sponsor	Trials
Other	553
Industry	101
NIH	49

Doxycycline Clinical Trials Update and Market Projection (2025–2035): Pipeline Status, Competitive Landscape, and Revenue Scenarios

Last updated: May 20, 2026

Executive summary

• Doxycycline is an established, off-patent antibiotic with broad global availability; new clinical development is primarily incremental (new formulations, combinations, pharmacokinetic claims) rather than blockbuster, first-in-class innovation.
• Market outlook remains stable-to-moderately growing through 2035, supported by persistent demand in respiratory infections, skin/rosacea indications, and empiric antibiotic use, with growth tempered by stewardship, resistance risk, and generics.
• Commercial upside concentrates in branded-spec and specialty formulations (e.g., modified-release or dermatology-focused products) and in combination products where formulation and labeling create defensible commercial differentiation.
• Based on the typically competitive, generic-heavy category structure for doxycycline, revenue projections should be modeled around volume growth plus price compression, not premium share expansion.

How big is the doxycycline market in 2024, and what are the forecast drivers for 2025–2035?

Answer: Global doxycycline demand is forecast to grow at a low-to-mid single-digit CAGR over 2025–2035, driven by ongoing respiratory and dermatology use, with headwinds from antibiotic stewardship and pricing pressure from generics.

Key demand drivers

• Respiratory and community-acquired infection use (where tetracyclines remain common options)
• Dermatology indications, including acne and rosacea-related prescribing patterns
• Vector-borne disease prophylaxis and treatment use in endemic areas
• Third-party prescribing substitutability: doxycycline is often viewed as a therapeutic alternative within the tetracycline class

Key constraints

• Antibiotic stewardship and guideline tightening reduces broad empiric use in some geographies and settings
• Resistance patterns can shift prescribing behavior and limit “first-choice” status
• Price compression due to widespread generic penetration

Market projection framework for commercial planning

Use a two-factor model:

1. Volume: baseline epidemiology plus guideline adherence and substitution effects
2. Net price: brand versus generic mix, rebate structures, and tender-driven pricing

What is the current clinical trials pipeline for doxycycline (2025 update)?

Answer: Trial activity for doxycycline in 2025 is expected to cluster around:

• Formulation development (bioavailability, GI tolerability, modified release)
• New labeling or comparative studies (non-inferiority versus existing doxycycline products)
• Adjunctive and combination regimens in targeted therapeutic contexts
• Special populations studies (pediatrics, pregnancy status labeling refinement where applicable)

How to interpret “pipeline” risk for doxycycline

• Doxycycline’s core molecule is mature; most “pipeline” entries are incremental, meaning:
  • regulatory differentiation tends to be clinical-endpoint or PK/BE-driven
  • competitive impact comes from local market approvals and payer/listing outcomes, not from fundamental therapeutic novelty

Which clinical trial phases are most common for doxycycline right now (Phase 1 vs Phase 3)?

Answer: The doxycycline development landscape is typically skewed toward Phase 1/2 PK, BE, tolerability, and comparative Phase 3/endpoint studies when seeking labeling expansion. For an off-patent molecule, Phase 3 programs are usually targeted to secure incremental commercial advantages.

What Phase distribution usually implies

• More Phase 1/BE: lower regulatory complexity but also lower defensibility; faster entry for competitors
• Endpoint-driven Phase 3: higher hurdle but can support specific new indication or formulation-with-label differentiation

What patents protect doxycycline, and when do they expire?

Answer: The active ingredient doxycycline itself is off-patent in most markets; exclusivity that matters commercially tends to be held by:

• formulation patents (modified release, granulation, excipient system, dissolution profile)
• combination patents (doxycycline with a second active)
• method-of-use and dosing regimen patents (where still present, often narrower)

Patent estate structure that matters for commercial risk

• For an off-patent ingredient, the highest litigation and settlement probability typically lies in:
  • specific branded dosage forms
  • specific combination products
  • specific regional formulation IP
• Generic entry disputes usually track to Orange Book listed patents for US products, or to national listing regimes in EU member states.

What is the Orange Book status of doxycycline products in the U.S.?

Answer: Because doxycycline is widely genericized, Orange Book listings exist mainly for specific branded products and formulations, not for the base API across the board.

How Orange Book status translates to launch timing

• If Orange Book listed patents exist for a specific branded doxycycline product:
  • generic entry timing depends on patent expiration + pediatric exclusivity + any granted extensions
  • Paragraph IV challenges occur when generics seek to enter prior to the listed patent expiry

Do generic doxycycline products face Paragraph IV challenges, and what is the typical playbook?

Answer: Where branded doxycycline products still maintain listed patents, Paragraph IV challenges are standard in the U.S. However, the molecule’s age reduces the frequency of “core API” disputes; challenges often target formulation or method-of-use patents.

Common targets in doxycycline Paragraph IV

• dissolution enhancement and release profile claims
• dosage form manufacturing or stability claims
• specific dosing strategies for labeled use

What patent litigation affects doxycycline, and who has been challenging whom?

Answer: Doxycycline litigation risk is generally product-specific and regional. In practice, the biggest driver is whether a branded formulation has still-active listed patents.

Litigation impact mechanics

• A generic launch is often delayed by:
  • active injunction exposure
  • damages exposure in Hatch-Waxman litigation
• Settlement agreements typically:
  • shift launch dates to post-expiry windows
  • include non-entry or limited-entry terms for certain dosage forms or strengths

How strong is the patent estate for doxycycline formulations, and where are the weak spots?

Answer: Patent strength for doxycycline is typically narrow and formulation-specific. Weak spots usually include:

• claims covering broad excipient alternatives or generic dissolution modifications
• manufacturing parameter claims that lack clear experimental boundaries
• method-of-use claims that overlap with labeled standard-of-care practices

Defensibility grading for incremental IP

• Stronger: claims with clear technical constraints tied to the approved formulation and showing a measurable property
• Weaker: broad genus claims without distinct performance benchmarks

What formulations of doxycycline have the biggest market share, and why?

Answer: The dominant commercial formats are generally oral immediate-release capsules/tablets and oral controlled or modified-release variants where local tolerance/behavioral benefits improve adherence.

Differentiation levers that move volume

• GI tolerability and dosing frequency
• prescription habit and payer formulary positioning
• dermatology product positioning when supported by labeling and marketing

How do doxycycline and alternative antibiotics compare on efficacy, stewardship, and switching risk?

Answer: Doxycycline competes within tetracyclines and across multiple empiric pathways. Switching risk is high because doxycycline is a substitute within antibiotic classes, and generic availability reduces differentiation.

Switching risk drivers

• local guideline changes
• resistance and susceptibility reports
• payer restrictions or step edits
• safety and tolerability perceptions

What is the biosimilar risk for doxycycline?

Answer: There is no biosimilar construct for doxycycline. Competitive risk comes from generic small-molecule entry, not biologics.

When does doxycycline lose exclusivity in major markets?

Answer: For the active ingredient doxycycline, exclusivity is generally already expired in most major markets. What remains are:

• formulation-specific or product-specific rights
• marketing authorization lifecycle constraints and patent term extensions on specific dosage forms, where present

What generic entry risks exist for branded doxycycline products?

Answer: Generic entry risk is highest where:

• a branded doxycycline product holds limited, formulation-scoped patents that can be designed around
• Orange Book patents expire soon or are vulnerable to early invalidation
• local regulators and tenders favor cost-minimizing bids once patent risk clears

Which companies are most exposed to doxycycline pricing pressure?

Answer: Exposure concentrates among:

• holders of branded doxycycline labels competing directly with mature generics
• companies relying on net price premiums that shrink as formularies switch to lowest acquisition cost

What is the expected competitive landscape for doxycycline through 2035?

Answer: The competitive structure stays highly fragmented and price-competitive, with niche brand differentiation in:

• dermatology-focused product positioning
• specialty tolerability-optimized formulations
• combination products in targeted indications where feasible

Clinical trials update: where is doxycycline likely to see incremental approvals?

Answer: Incremental approvals are most likely in:

• dermatology (where patient adherence and tolerability matter)
• PK optimization and BE-based product improvements
• regional clinical programs for labeling that tightens specificity

Market impact of incremental approvals

• Incremental labeling can change payer behavior and prescribing patterns, but:
  • broad antibiotic substitution keeps long-term share modest
  • sustained revenue requires either pricing power or differentiation that reduces switching

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Key tables

1) Doxycycline development and commercialization map (strategic interpretation)

Development theme	Typical clinical program	Regulatory pathway logic	Commercial outcome
Modified-release or improved tolerability	PK/BE, tolerability studies; sometimes comparative efficacy	BE-driven or supportive endpoint evidence	Higher adherence, modest premium where payers accept
Formulation change for GI or adherence	Phase 1/2	BE + tolerability	Local brand halo; limited long-term exclusivity
Combination products	Phase 2/3 with disease-specific endpoints	Label expansion tied to combination	Better differentiation; higher IP possibility
Method-of-use refinement	Controlled comparative or outcome studies	Label-specific evidence	Narrow but may support exclusivity if novel dosing

2) Revenue projection scenarios (planning ranges)

Scenario	Volume trend	Net price trend	Implied category growth (2025–2035)
Base	Low single-digit growth	Continued price erosion offset by mix	Low-to-mid single-digit
Upside	Faster uptake in priority indications + improved mix	Slower price decline	Mid single-digit
Downside	Stewardship reduces empiric use; rapid tender-driven price cuts	Faster price decline	Low single-digit or flat

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Key Takeaways

• Doxycycline’s near- and mid-term commercial trajectory is driven by generic market dynamics and product-level formulation differentiation, not by new blockbuster innovation.
• Clinical development in 2025 is most likely incremental and should be assessed through regulatory label impact and formulary positioning, not by assuming large efficacy step-changes.
• Patent and exclusivity constraints are generally product-specific, so revenue protection depends on whether remaining rights map to Orange Book or national patent listings tied to a specific dosage form.
• Market forecasts should use volume plus price compression modeling; upside depends on mix shift into differentiated formulations and on combination strategies.

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FAQs

1. Which doxycycline formulations have the best likelihood of holding up against generic substitution?
   Typically those with formulation-specific evidence supporting tolerability or performance claims tied to labeling.

2. How do FDA approvals for new doxycycline dosage forms affect payer formulary outcomes?
   Approvals that change tolerability, dosing frequency, or labeled use can shift formulary tiering, but savings pressure usually favors lowest-cost generics unless differentiation is durable.

3. Are there doxycycline combination products with meaningful late-stage development signals?
   Combination programs are the most relevant for higher defensibility, but their commercial impact is contingent on clear labeling and evidence-supported regimen advantages.

4. What is the strongest driver of doxycycline revenue: epidemiology or pricing?
   In mature markets, pricing and tender mechanics dominate net revenue; volume matters but usually moves within a constrained band.

5. Does antibiotic stewardship materially affect doxycycline projections?
   Yes. Stewardship policies can reduce broad empiric use and shift demand to more targeted settings, affecting growth rates.

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References (APA)

1. US Food and Drug Administration. (n.d.). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/
2. US Food and Drug Administration. (n.d.). Drugs@FDA. https://www.accessdata.fda.gov/scripts/cder/daf/