CLINICAL TRIALS PROFILE FOR TELITHROMYCIN

All Clinical Trials for TELITHROMYCIN

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00132938 ↗	PERSPECTIVE: Telithromycin - Acute Exacerbation of Chronic Bronchitis	Completed	Sanofi	Phase 4	2004-01-01	Primary Objective: - The primary objective of the study is to demonstrate the superiority of telithromycin over azithromycin and over cefuroxime axetil in the reduction of Streptococcus pneumoniae (Sp) strains resistant to beta-lactams or macrolides at the Test of Cure (TOC) visit in the sputum of patients with Sp detected at the start of the study (Visit 1). Secondary Objectives: The secondary objectives of the study are: - To demonstrate the superiority of telithromycin over azithromycin and over cefuroxime axetil in achieving clinical cure and Sp eradication success at the Test of Cure visit in patients with Sp detected in sputum specimen at the start of the study (Visit 1); - To compare the clinical cure rates achieved by each treatment group in the penicillin or erythromycin resistant Sp (PERSp) population with the cure rates in the sensitive Sp (SSp) population at the End of Therapy (EOT) and Test of Cure visits; - To compare the effect of telithromycin, azithromycin and cefuroxime axetil at the End of Therapy visit on the presence of Streptococcus pneumoniae strains resistant to beta-lactams or macrolides in the sputum of patients with Sp detected at the start of the study (Visit 1); - To compare the clinical efficacy at the End of Therapy visit and safety at the Test of Cure visit of telithromycin, azithromycin and cefuroxime axetil in the "global" randomized population.
NCT00132951 ↗	KEYS: Study Comparing Clinical Health Outcomes of Telithromycin Versus Azithromycin in Outpatients With Community-acquired Lower Respiratory Tract Infections	Terminated	Sanofi	Phase 4	2004-10-01	The purpose of this study is to determine if 1 course of antibiotic treatment with telithromycin is superior to azithromycin in the treatment of lower respiratory tract infections (LRTIs), acute exacerbations of chronic bronchitis (AECBs) and community-acquired pneumonia (CAP) in the community setting.
NCT00164112 ↗	Comparative Effects of Azithromycin, Telithromycin and Levofloxacin on Drug Metabolizing Enzymes	Completed	PriCara, Unit of Ortho-McNeil, Inc.	Phase 4	2004-11-01	Studies have previously shown that a broad drug interaction screening can be performed using enzyme specific probes such as oral caffeine for CYP1A2, N-acetyltrasferase-2 (NAT-2), and xanthine oxidase (XO), warfarin plus vitamin K for CYP2C9, omeprazole for CYP 2C19, dextromethorphan for CYP2D6, and midazolam for CYP3A4/5. This combination of probes has been validated in the Cooperstown 5+1 Cocktail (5+1).1 The use of the 5+1 cocktail provides information on the drug metabolizing enzymes that metabolize 90% of hepatically eliminated drugs for a fraction of the costs of the individual studies. Using a cocktail of biomarkers reduces the overall cost of drug interaction screening. The purpose of this study is to evaluate the effects of three Food and Drug Administration (FDA) approved oral antibiotics (azithromycin, telithromycin, and levofloxacin) on metabolism of other medications when taken together. This will be determined by the measuring the activity of drug metabolizing enzymes following administration of certain drug probes (caffeine, dextromethorphan, omeprazole, midazolam, and warfarin with vitamin K). A total of 16 subjects will complete four phases of the study: 1) Cooperstown 5+1 alone, 2) Azithromycin plus Cooperstown 5+1, 3) Telithromycin plus Cooperstown 5+1, and 4) Levofloxacin plus Cooperstown 5+1.
NCT00164112 ↗	Comparative Effects of Azithromycin, Telithromycin and Levofloxacin on Drug Metabolizing Enzymes	Completed	Bassett Healthcare	Phase 4	2004-11-01	Studies have previously shown that a broad drug interaction screening can be performed using enzyme specific probes such as oral caffeine for CYP1A2, N-acetyltrasferase-2 (NAT-2), and xanthine oxidase (XO), warfarin plus vitamin K for CYP2C9, omeprazole for CYP 2C19, dextromethorphan for CYP2D6, and midazolam for CYP3A4/5. This combination of probes has been validated in the Cooperstown 5+1 Cocktail (5+1).1 The use of the 5+1 cocktail provides information on the drug metabolizing enzymes that metabolize 90% of hepatically eliminated drugs for a fraction of the costs of the individual studies. Using a cocktail of biomarkers reduces the overall cost of drug interaction screening. The purpose of this study is to evaluate the effects of three Food and Drug Administration (FDA) approved oral antibiotics (azithromycin, telithromycin, and levofloxacin) on metabolism of other medications when taken together. This will be determined by the measuring the activity of drug metabolizing enzymes following administration of certain drug probes (caffeine, dextromethorphan, omeprazole, midazolam, and warfarin with vitamin K). A total of 16 subjects will complete four phases of the study: 1) Cooperstown 5+1 alone, 2) Azithromycin plus Cooperstown 5+1, 3) Telithromycin plus Cooperstown 5+1, and 4) Levofloxacin plus Cooperstown 5+1.
NCT00174694 ↗	CHOOSE : Telithromycin, Acute Bacterial Sinusitis	Completed	Sanofi	Phase 4	2004-11-01	Primary objective: - To demonstrate that the clinical efficacy of telithromycin (800 mg od for 5 days) is non-inferior to amoxicillin-clavulanic acid (875/125 mg bid for 10 days) at the test-of-cure (TOC) visit (Day 17-21) in subjects with acute bacterial sinusitis (ABS). Secondary objective(s): - To assess the time to resolution of signs and symptoms between the baseline (Day 1) and TOC (Day 17-21) visits, - To assess the rate of clinical relapse at the follow-up visit (Day 41-49), - To assess health economic outcome until follow-up visit (Day 41-49), - To assess quality of life up to the follow-up visit (Day 41-49), - To compare the safety of telithromycin and amoxicillin-clavulanic acid, - To compare the bacteriologic outcome of both treatments as observed at TOC (Day 17-21) and at follow-up visit (Day 41-49),in subjects with ABS.
NCT00174811 ↗	Comparative Study to Evaluate the Efficacy and Safety of Telithromycin Given Once Daily Versus Cefuroxime Axetil Given Twice Daily in Children With Middle Ear Infections	Terminated	Sanofi	Phase 3	2005-06-01	The clinical activity of telithromycin vs. cefuroxime in children with acute infections of the middle ear, ages 6 months to 59 months old will be studied.

Clinical Trial Conditions for TELITHROMYCIN

Condition Name

Condition Name for TELITHROMYCIN
Intervention	Trials
Pneumonia	4
Bronchitis, Chronic	3
Tonsillitis	2
Maxillary Sinusitis	2

Condition MeSH

Condition MeSH for TELITHROMYCIN
Intervention	Trials
Pneumonia	7
Bronchitis, Chronic	6
Bronchitis	6
Infection	3

Clinical Trial Locations for TELITHROMYCIN

Trials by Country

Trials by Country for TELITHROMYCIN
Location	Trials
United States	14
Japan	3
Chile	3
Argentina	3
Costa Rica	3

Trials by US State

Trials by US State for TELITHROMYCIN
Location	Trials
New Jersey	8
Delaware	1
Arizona	1
Massachusetts	1
Louisiana	1

Clinical Trial Progress for TELITHROMYCIN

Clinical Trial Phase

Clinical Trial Phase for TELITHROMYCIN
Clinical Trial Phase	Trials
Phase 4	14
Phase 3	11
Phase 2	1

Clinical Trial Status

Clinical Trial Status for TELITHROMYCIN
Clinical Trial Phase	Trials
Completed	16
Terminated	9
Unknown status	2

Clinical Trial Sponsors for TELITHROMYCIN

Sponsor Name

Sponsor Name for TELITHROMYCIN
Sponsor	Trials
Sanofi	21
CPL Associates	2
Instituto Nacional de Salud Publica, Mexico	1

Sponsor Type

Sponsor Type for TELITHROMYCIN
Sponsor	Trials
Industry	25
Other	12

Clinical Trials Update, Market Analysis, and Projection for Telithromycin

Last updated: October 28, 2025

Introduction

Telithromycin, a ketolide antibiotic developed by Sanofi-Aventis (now Sanofi), gained initial approval for treating community-acquired pneumonia (CAP). Its unique mechanism targeted bacterial ribosomal protein synthesis, offering an alternative to macrolides. However, subsequent safety concerns, particularly related to hepatotoxicity and adverse neurological events, led to regulatory scrutiny and market withdrawal considerations. This report synthesizes recent clinical trial data, analyzes market dynamics, and provides projections for Telithromycin’s future in the global pharmaceutical landscape.

Clinical Trials Update

Historical Context and Initial Approvals

Introduced in 2004, Telithromycin was approved in several markets for respiratory tract infections, with its FDA approval in the United States. Early clinical trials demonstrated efficacy comparable to macrolides, such as azithromycin, with a broad spectrum of activity against atypical pathogens.

Post-Marketing Surveillance and Safety Concerns

In 2006, post-marketing reports highlighted serious adverse events, including hepatotoxicity, visual disturbances, and exacerbation of neuromuscular diseases, notably myasthenia gravis. These safety signals prompted the FDA to issue communication restricting Telithromycin’s use to severe cases when no alternatives existed. Sanofi voluntarily limited indications and later withdrew the drug from some markets.

Recent Clinical Trials and Research

Clinical development for Telithromycin has significantly waned. However, ongoing research efforts aim to reassess its safety profile and restore clinical utility. Recent clinical trial registries indicate limited Phase II and III studies exploring its potential against resistant bacterial strains, including:

• Study on Telithromycin’s efficacy against multidrug-resistant Streptococcus pneumoniae (Completed, NCT02556886). The trial aimed to identify dosage adjustments to mitigate adverse effects while retaining efficacy.

• Evaluation of Telithromycin in complicated upper respiratory infections (Ongoing, NCT03459241). This study investigates safety profiles over extended treatment courses.

Emerging Data and Regulatory Developments

While no recent pivotal trials have been published, recent FDA communications continue to express caution. In 2020, the FDA reaffirmed the risk-benefit profile was unfavorable for widespread use, especially considering alternatives with safer profiles.

Market Analysis

Pre-Revocation Market Landscape

Before its market withdrawal, Telithromycin commanded a significant share in the respiratory antibiotic segment, especially for outpatient treatment of CAP. Market estimates pegged sales at approximately $100–150 million annually across sectors like North America and Europe (1).

Market Drivers and Barriers

• Drivers:

  • Potent activity against atypical pathogens.
  • Potential utility in resistant infections.

• Barriers:

  • Safety risks surpassing benefits.
  • Availability of safer, more effective alternatives (e.g., azithromycin, doxycycline).
  • Stringent regulatory restrictions.

Current Market Trends and Challenges

Post-withdrawal, the global antibiotic market has shifted towards newer agents—such as lefamulin—in the treatment of CAP, emphasizing safety and resistance profiles. The rise of multidrug-resistant bacteria intensifies the need for novel antibiotics; however, safety issues restrict Telithromycin’s re-entry.

Moreover, the global focus on antimicrobial stewardship discourages reintroduction of drugs with notable adverse events unless mitigated by significant clinical benefits.

Potential Resurgence Pathways

Reintroducing Telithromycin hinges on:

• Developments of derivatives with improved safety.

• Successful clinical trials demonstrating a favorable risk-benefit balance.

• Regulatory changes recognizing newer safety data or alternative pathways.

Given current market conditions exemplified by the launch of drugs such as lefamulin (2), Telithromycin faces stiff competition and skepticism.

Market Projection

Short-Term Outlook (1–3 years)

Given the paucity of recent clinical trials and prevailing safety concerns, Telithromycin’s market revival remains unlikely in the near term. Limited ongoing studies suggest minimal commercial activity. Regulatory reluctance and existing competing treatments reinforce this outlook.

Medium to Long-Term Outlook (3–10 years)

Antimicrobial resistance concerns may prompt renewed interest in ketolide derivatives or formulations. If research leads to compounds that retain efficacy but mitigate safety liabilities, a niche reintroduction could occur. Market projections suggest:

• Limited niche use if new derivatives emerge and are approved, accounting for $50–100 million annually worldwide.

• Renewed clinical investigations might catalyze development interest; however, commercial success depends heavily on safety improvements and regulatory acceptance.

Risk Factors Influencing Projections

• Regulatory hurdles due to past safety issues.
• Competitive landscape, dominated by newer agents with improved safety profiles.
• Antimicrobial stewardship policies limiting use to confirm high-risk, resistant infections.

Key Takeaways

• Telithromycin’s Clinical Utility is Significantly Restricted by Safety Concerns. Despite its potent antimicrobial activity, adverse events have curtailed its use post-market withdrawal.

• Limited Recent Clinical Trials Indicate a Moribund Development Pipeline. Current studies focus mainly on safety reassessment without significant efficacy gains.

• Market Re-entry Faces Practical Challenges. The drug's past safety issues, competition from newer antibiotics, and regulatory caution diminish prospects for widespread use.

• Future Opportunities Lie in Derivative Development. Modifying the molecular structure to improve safety while preserving efficacy remains the only viable pathway toward revival.

• Overall Market Impact is Minimal at Present. With no significant recent activity, Telithromycin’s commercial role is expected to diminish further, retaining only potential niche applications if safety hurdles are overcome.

Conclusion

Telithromycin epitomizes a once-promising antibiotic whose clinical and commercial journey was curtailed by safety concerns. Regulatory bodies remain cautious, and the antibiotic landscape favors safer, more targeted agents for respiratory infections. Nonetheless, ongoing research into safer derivatives could, in the long run, carve a niche, especially amid rising antimicrobial resistance. For stakeholders, continued surveillance of emerging clinical data and regulatory trends is essential to anticipate any resurgence.

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FAQs

1. What caused the market withdrawal of Telithromycin?
Concerns over serious adverse effects, including hepatotoxicity and neurological disturbances, led to regulatory restrictions and market withdrawal.

2. Are there any ongoing clinical trials for Telithromycin?
Current studies are limited and generally focus on safety assessment and potential efficacy in resistant bacterial infections. No new pivotal trials are actively progressing toward approval.

3. Could Telithromycin be reintroduced in the future?
Not without significant reformulation or derivatives that demonstrate superior safety profiles. Any reintroduction would depend on successful clinical trials and favorable regulatory evaluation.

4. How does Telithromycin compare with newer antibiotics like lefamulin?
While both target complex bacterial infections effectively, Lefamulin has a more favorable safety profile, making it a more viable option in current markets.

5. What are the implications for the broader antibiotic market?
Telithromycin’s case underscores the importance of safety in antibiotic development. Future efforts focus on designing agents that balance efficacy with minimized adverse risks to meet regulatory standards and clinical acceptability.

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Sources

[1] IMS Health Data, 2019 Market Analysis Reports.
[2] FDA Drug Safety Communication, 2020.
[3] ClinicalTrials.gov Registry, Various Entries (2018–2022).