CLINICAL TRIALS PROFILE FOR ZITHROMAX

505(b)(2) Clinical Trials for ZITHROMAX

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 ZITHROMAX

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00035347 ↗	Intravenous Azithromycin Plus Intravenous Ceftriaxone Followed by Oral Azithromycin With Intravenous Levofloxacin Followed by Oral Levofloxacin for the Treatment of Moderate to Severely Ill Hospitalized Patients With Community Acquired Pneumonia	Completed	Pfizer	Phase 4	2001-01-01	A trial in which patients over 18 years of age who are hospitalized with community acquired pneumonia and are otherwise eligible for entry into the study are randomly selected to receive one of two treatment regimens. After written informed consent is obtained, patients will receive one of the following two treatment regimens: 1) intravenous administration of azithromycin and ceftriaxone followed by azithromycin tablets, or 2) intravenous administration of levofloxacin followed by levofloxacin tablets. At least four study visits are normally conducted up to approximately one month after starting therapy. The objective of this study is to compare the safety and efficacy of the two treatment regimens.
NCT00137007 ↗	Zithromax EV in Community-Acquired Pneumonia (CAP)	Completed	Pfizer	Phase 4	2003-11-01	The intravenous (IV) regimen containing azithromycin (Zithromax) plus ampicillin-sulbactam is consistent with current guidelines for the treatment of CAP. In fact the International guidelines for the treatment of CAP in hospitalised patients suggests the use of a combination between a b-lactam and a macrolide. This trial will allow investigators to evaluate the efficacy of azithromycin plus ampicillin-sulbactam in the treatment of hospitalized subjects with community acquired pneumonia. In addition, this trial will allow investigators to evaluate the safety and toleration of combination therapy.
NCT00237445 ↗	Study Comparing the Clinical Efficacy and Health Outcomes of Outpatients With Mild to Moderate Community-Acquired Pneumonia (CAP) Treated With Either Telithromycin Once Daily for 7 Days, or Azithromycin Once Daily for 5 Days	Terminated	Sanofi	Phase 4	2005-11-01	A multinational, multicenter, randomized, double-blind, study in areas of high pneumococcal resistance comparing the clinical efficacy and health outcomes of outpatients with mild to moderate Community-Acquired Pneumonia (CAP) treated with either telithromycin once daily for 7 days, or azithromycin once daily for 5 days
NCT00266851 ↗	AZMATICS: AZithroMycin/Asthma Trial In Community Settings	Completed	American Academy of Family Physicians	Phase 3	2006-01-01	The purpose of this study is to assess the effectiveness of the azalide macrolide azithromycin in adults with persistent asthma. Research Question: Will a 12-week treatment with the antibiotic, azithromycin, result in a statistically significant and clinically meaningful improvement in overall asthma symptoms and other patient-oriented asthma outcomes one year after initiation of treatment of adult primary care patients with asthma? Experimental Design: The investigators propose a one-year randomized, placebo-controlled, blinded (investigator, patient, data collector, data analyst) trial of 12 weekly doses of azithromycin/placebo as adjunctive therapy (in addition to usual care) along with a parallel observational cohort who will participate 'open label' in 100 adult asthma patients recruited from practice-based research networks (e.g., Wisconsin Research and Education Network (WREN) and others). This "practical clinical trial" will (1) enroll a representative sample of asthma patients encountered in the practices of primary care physicians, (2) employ standard clinical trial methodology to ensure internally valid results and (3) measure outcomes important to patients, so that the results will be valid and applicable to the kinds of asthma patients encountered by family physicians and other primary care providers. Active study sites - - Wisconsin: Augusta, Cross Plains, La Crosse, Marshfield, Milwaukee, Madison, - Mauston, Rice Lake, Tomah, Wausau - Colorado: Monument - Illinois: Peoria - Nevada: Reno - North Carolina: Granite Falls - North Dakota: Minot - Ohio: Cleveland, Berea - Oklahoma: Ardmore, Claremore, Edmond, Lawton, Oklahoma City, Stroud, Tulsa, Weatherford - Rhode Island: East Providence
NCT00266851 ↗	AZMATICS: AZithroMycin/Asthma Trial In Community Settings	Completed	Dean Foundation	Phase 3	2006-01-01	The purpose of this study is to assess the effectiveness of the azalide macrolide azithromycin in adults with persistent asthma. Research Question: Will a 12-week treatment with the antibiotic, azithromycin, result in a statistically significant and clinically meaningful improvement in overall asthma symptoms and other patient-oriented asthma outcomes one year after initiation of treatment of adult primary care patients with asthma? Experimental Design: The investigators propose a one-year randomized, placebo-controlled, blinded (investigator, patient, data collector, data analyst) trial of 12 weekly doses of azithromycin/placebo as adjunctive therapy (in addition to usual care) along with a parallel observational cohort who will participate 'open label' in 100 adult asthma patients recruited from practice-based research networks (e.g., Wisconsin Research and Education Network (WREN) and others). This "practical clinical trial" will (1) enroll a representative sample of asthma patients encountered in the practices of primary care physicians, (2) employ standard clinical trial methodology to ensure internally valid results and (3) measure outcomes important to patients, so that the results will be valid and applicable to the kinds of asthma patients encountered by family physicians and other primary care providers. Active study sites - - Wisconsin: Augusta, Cross Plains, La Crosse, Marshfield, Milwaukee, Madison, - Mauston, Rice Lake, Tomah, Wausau - Colorado: Monument - Illinois: Peoria - Nevada: Reno - North Carolina: Granite Falls - North Dakota: Minot - Ohio: Cleveland, Berea - Oklahoma: Ardmore, Claremore, Edmond, Lawton, Oklahoma City, Stroud, Tulsa, Weatherford - Rhode Island: East Providence
NCT00266851 ↗	AZMATICS: AZithroMycin/Asthma Trial In Community Settings	Completed	Pfizer	Phase 3	2006-01-01	The purpose of this study is to assess the effectiveness of the azalide macrolide azithromycin in adults with persistent asthma. Research Question: Will a 12-week treatment with the antibiotic, azithromycin, result in a statistically significant and clinically meaningful improvement in overall asthma symptoms and other patient-oriented asthma outcomes one year after initiation of treatment of adult primary care patients with asthma? Experimental Design: The investigators propose a one-year randomized, placebo-controlled, blinded (investigator, patient, data collector, data analyst) trial of 12 weekly doses of azithromycin/placebo as adjunctive therapy (in addition to usual care) along with a parallel observational cohort who will participate 'open label' in 100 adult asthma patients recruited from practice-based research networks (e.g., Wisconsin Research and Education Network (WREN) and others). This "practical clinical trial" will (1) enroll a representative sample of asthma patients encountered in the practices of primary care physicians, (2) employ standard clinical trial methodology to ensure internally valid results and (3) measure outcomes important to patients, so that the results will be valid and applicable to the kinds of asthma patients encountered by family physicians and other primary care providers. Active study sites - - Wisconsin: Augusta, Cross Plains, La Crosse, Marshfield, Milwaukee, Madison, - Mauston, Rice Lake, Tomah, Wausau - Colorado: Monument - Illinois: Peoria - Nevada: Reno - North Carolina: Granite Falls - North Dakota: Minot - Ohio: Cleveland, Berea - Oklahoma: Ardmore, Claremore, Edmond, Lawton, Oklahoma City, Stroud, Tulsa, Weatherford - Rhode Island: East Providence
NCT00266851 ↗	AZMATICS: AZithroMycin/Asthma Trial In Community Settings	Completed	University of Wisconsin, Madison	Phase 3	2006-01-01	The purpose of this study is to assess the effectiveness of the azalide macrolide azithromycin in adults with persistent asthma. Research Question: Will a 12-week treatment with the antibiotic, azithromycin, result in a statistically significant and clinically meaningful improvement in overall asthma symptoms and other patient-oriented asthma outcomes one year after initiation of treatment of adult primary care patients with asthma? Experimental Design: The investigators propose a one-year randomized, placebo-controlled, blinded (investigator, patient, data collector, data analyst) trial of 12 weekly doses of azithromycin/placebo as adjunctive therapy (in addition to usual care) along with a parallel observational cohort who will participate 'open label' in 100 adult asthma patients recruited from practice-based research networks (e.g., Wisconsin Research and Education Network (WREN) and others). This "practical clinical trial" will (1) enroll a representative sample of asthma patients encountered in the practices of primary care physicians, (2) employ standard clinical trial methodology to ensure internally valid results and (3) measure outcomes important to patients, so that the results will be valid and applicable to the kinds of asthma patients encountered by family physicians and other primary care providers. Active study sites - - Wisconsin: Augusta, Cross Plains, La Crosse, Marshfield, Milwaukee, Madison, - Mauston, Rice Lake, Tomah, Wausau - Colorado: Monument - Illinois: Peoria - Nevada: Reno - North Carolina: Granite Falls - North Dakota: Minot - Ohio: Cleveland, Berea - Oklahoma: Ardmore, Claremore, Edmond, Lawton, Oklahoma City, Stroud, Tulsa, Weatherford - Rhode Island: East Providence

Clinical Trial Conditions for ZITHROMAX

Condition Name

Condition Name for ZITHROMAX
Intervention	Trials
Trachoma	8
Healthy	7
Malaria	6
COVID-19	5

Condition MeSH

Condition MeSH for ZITHROMAX
Intervention	Trials
Infections	13
Infection	11
Communicable Diseases	11
Malaria	8

Clinical Trial Locations for ZITHROMAX

Trials by Country

Trials by Country for ZITHROMAX
Location	Trials
United States	201
Canada	15
France	14
Australia	11
United Kingdom	8

Trials by US State

Trials by US State for ZITHROMAX
Location	Trials
California	20
Maryland	12
Texas	9
Alabama	8
Illinois	8

Clinical Trial Progress for ZITHROMAX

Clinical Trial Phase

Clinical Trial Phase for ZITHROMAX
Clinical Trial Phase	Trials
Phase 4	34
Phase 3	17
Phase 2/Phase 3	4

Clinical Trial Status

Clinical Trial Status for ZITHROMAX
Clinical Trial Phase	Trials
Completed	62
Recruiting	13
Not yet recruiting	9

Clinical Trial Sponsors for ZITHROMAX

Sponsor Name

Sponsor Name for ZITHROMAX
Sponsor	Trials
University of California, San Francisco	16
Pfizer	15
Bill and Melinda Gates Foundation	10

Sponsor Type

Sponsor Type for ZITHROMAX
Sponsor	Trials
Other	212
Industry	35
NIH	11

Last updated: May 21, 2026

Zithromax (Azithromycin) Clinical Trials Update, Market Analysis, and Exclusivity/Generic Outlook

Zithromax is the brand name for azithromycin. It is a widely available, off-patent small-molecule antibiotic with a mature FDA footprint and no credible near-term branded exclusivity renewal risk. The market is dominated by generics and authorized distributors, with periodic utilization spikes tied to respiratory infection seasons and guideline-driven prescribing patterns.

No new, brand-relevant clinical development pipeline materially changes expected commercial trajectory. The primary “update” items for Zithromax are therefore regulatory lifecycle events (generic entry timing by SKU), label maintenance, and any limited new-use evidence generation (often outside brand exclusivity).

What is Zithromax (azithromycin) FDA status and Orange Book listing for?

Answer: Zithromax is marketed as a prescription antibiotic; most azithromycin products are approved as generic equivalents to the original brand. Brand-specific exclusivity has long expired, and current competition is generic.

Which FDA application types cover azithromycin products?

• NDA-origin branded labeling: Original Zithromax approvals predate modern Orange Book Paragraph IV frameworks and typically anchor current therapeutic labeling.
• ANDA-origin generic products: Most current azithromycin tablets, capsules, and suspensions are approved via ANDAs referencing the branded NDA/label.

What is the practical Orange Book take for “Zithromax”?

For business planning, “Zithromax” should be treated as a reference-label asset, not a protected product. Claims that constrain generic manufacturing would need to be tied to still-active formulation or method-of-use patents, which are not relevant for forecasting branded volume for decades-old antibiotic chemistry unless a specific, currently listed patent has enforceable coverage (rare for legacy azithromycin).

What clinical trials are currently updating azithromycin (Zithromax) evidence?

Answer: Most azithromycin clinical activity in the public domain is comparative effectiveness, real-world outcomes, resistance surveillance linked trials, and guideline-supporting studies. These typically do not create exclusivity for legacy branded products.

What trial types drive ongoing azithromycin publications?

• Respiratory tract infection trials: Acute bacterial infections, community-acquired respiratory syndromes, and comparative outcomes versus other macrolides or beta-lactams.
• Cystic fibrosis and bronchiectasis infection studies: Pathogen eradication and exacerbation reduction.
• Safety and tolerability registries: QT prolongation risk characterization, GI tolerability, pediatric dosing confirmation in practice settings.
• Antimicrobial stewardship observational studies: Outbreak management, resistance trends, and prescribing appropriateness analyses.

What does a clinical-trials “update” mean commercially for Zithromax?

• New evidence can shift prescribing patterns between azithromycin and competing antibiotics.
• Evidence rarely restores brand pricing power for an off-patent molecule.
• Net market impact is usually absorbed by generic erosion, with volume shifting across manufacturers.

When does azithromycin lose exclusivity and what does that mean for Zithromax?

Answer: Zithromax has long since passed patent and regulatory exclusivity eras typical of first-in-class antibacterial launches. Commercial forecasts should assume generic availability across standard oral dosage forms.

What exclusivity drivers matter for old antibiotics?

• Composition-of-matter expiration: Long expired for azithromycin itself.
• Formulation or polymorph patents: Can extend specific SKUs but are generally weak versus broad generic penetration for a core antibiotic.
• Method-of-use patents: Common for new indications, but azithromycin’s broad label historically reduced feasibility of lasting exclusivity.

How to model “Zithromax” market volume post-exclusivity?

• Use therapeutic class baselines for macrolide utilization and seasonality.
• Allocate shares to manufacturers based on generic presence, supply reliability, and formulary status, not branded IP.

How many patents protect azithromycin (Zithromax) today and are any still enforceable?

Answer: For forecasting branded Zithromax, enforceable patent coverage is not a meaningful near-term determinant because the molecule is extensively generic.

Where IP still shows up even for mature antibiotics

• Specific dosage form improvements: Extended-release systems, granulation processes, taste-masking for pediatric suspensions.
• Manufacturing methods: Less often decisive for generic entry now that process know-how is widely industrialized.
• Skin/eye or niche use formulations: If listed, they constrain only narrow SKUs rather than whole-market Zithromax economics.

What generic entry risks exist for Zithromax and how do Paragraph IV challenges apply?

Answer: Paragraph IV challenges are not a credible near-term risk lens for Zithromax because the active substance is off-patent and generic entry is already entrenched.

How should businesses interpret “Paragraph IV” for Zithromax-like assets?

• Paragraph IV relevance is limited to still-protected formulation or method-of-use patents tied to specific ANDA products.
• Even when such patents exist, the market effect is SKU-specific and absorbed by generic substitution.

What is the market size and growth outlook for azithromycin/Zithromax in the US and ex-US?

Answer: The market is large and mature, with growth driven by population needs, seasonality, and guideline mix, offset by ongoing generic price compression.

US market mechanics

• Primary drivers: respiratory infection burden, pediatric and adult prescribing rates, guideline shifts between macrolides and alternatives, and antimicrobial stewardship policies.
• Competitive structure: multi-winner generic ecosystem with frequent price resets through auctions and PBM contracting.
• Brand economics: Zithromax branded volume is typically a minority of total azithromycin units unless a segment remains brand-preferred via patient support programs or specific payer contracting.

Ex-US mechanics

• Regulatory heterogeneity: varying generic penetration rates by country.
• Local supply constraints: can temporarily increase realized prices even after IP expiry.
• Quality and regulatory compliance: can gate new entrants.

How does azithromycin pricing evolve after generic substitution, and what is the cost/benefit for payers?

Answer: After full generic substitution, pricing follows a commodity curve constrained by contracting dynamics and manufacturing capacity.

Payer incentives

• Prefer lowest net cost with adequate clinical equivalence.
• Use formularies to steer toward preferred generics and restrict higher-cost brands.
• Reassess based on safety communications (QT risk) and stewardship policy changes.

What formulations of Zithromax matter most for commercial projection?

Answer: Standard oral formulations dominate: tablets/capsules and pediatric suspension. Commercial projections should focus on unit demand and contract pricing by dosage form.

Dose form demand patterns

• Pediatric suspension: influenced by seasonal pediatric visits and school-year infection patterns.
• Adult tablets/capsules: driven by outpatient respiratory infection caseloads.
• Any niche packs: usually have limited incremental value versus generic substitution.

What safety and label-change dynamics can impact Zithromax utilization?

Answer: QT prolongation risk communication and broader macrolide safety surveillance can influence prescribing thresholds but rarely shut down the class.

What label or safety events shift demand?

• New safety alerts affecting cardiac risk screening.
• Changes in recommended use duration.
• Reinforced stewardship limitations for viral syndromes and inappropriate indications.

What is the competitive landscape versus other macrolides and antibiotics?

Answer: Azithromycin competes across:

• Other macrolides: clarithromycin, erythromycin (varies by region and availability).
• Beta-lactams: amoxicillin-clavulanate and cephalosporins (often preferred for certain bacterial indications).
• Respiratory fluoroquinolones: generally constrained by safety concerns and stewardship.

How should forecasts treat class substitution?

Forecast azithromycin volume using:

• estimated macrolide share of outpatient bacterial respiratory treatment,
• stewardship constraints,
• and relative net prices versus primary alternatives.

What does “clinical trials update” imply for manufacturing and supply chain planning?

Answer: For off-patent azithromycin, the operational priority is supply resilience and quality throughput, not brand-specific trial-driven scale-up.

Manufacturing factors that change realized sales

• API supply constraints and batch-release timelines.
• Suspension taste and stability requirements affecting line utilization.
• QA deviations that can cause temporary shortages, enabling short-lived price lifts.

Key Takeaways

• Zithromax (azithromycin) is off-patent and faces entrenched generic competition; exclusivity is not a near-term commercial lever.
• “Clinical trials update” primarily affects prescribing patterns and guideline adherence, not branded IP restoration.
• Market outlook is mature and pricing is commodity-like; growth depends on infectious disease burden, seasonality, and macrolide share versus substitutes.
• For projection, focus on unit demand by dosage form, net pricing under PBM and government contracting, and supply/shortage dynamics rather than brand-exclusive pipeline events.

FAQs

1) Does Zithromax have any active exclusivity left for new indications?
Given the mature status of azithromycin, any exclusivity would be SKU- or indication-narrow and not expected to restore broad branded dominance.

2) Are there ongoing trials comparing azithromycin to other antibiotics for respiratory infections?
Yes, most ongoing studies are comparative effectiveness and stewardship-linked, with limited relevance to brand exclusivity.

3) What risks could reduce azithromycin utilization quickly?
Tightening stewardship policies, label safety communications affecting cardiac risk management, and rapid formulary shifts to alternative agents.

4) How do shortages affect azithromycin market pricing after generic entry?
Shortages can raise net prices temporarily across generics, but competitive replenishment typically returns pricing to contracted levels.

5) What dosage forms drive the largest unit volume for azithromycin?
Oral tablets/capsules and pediatric suspensions generally dominate outpatient demand.

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References

1. U.S. Food and Drug Administration (FDA). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. FDA.
2. U.S. Food and Drug Administration (FDA). Drug Trials Snapshots. FDA.
3. FDA Adverse Event Reporting System (FAERS). FDA.