CLINICAL TRIALS PROFILE FOR RITONAVIR

505(b)(2) Clinical Trials for ritonavir

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	NCT00196625 ↗	Salvage Therapy With Amprenavir, Lopinavir and Ritonavir in HIV-Infected Patients in Virological Failure.	Completed	French National Agency for Research on AIDS and Viral Hepatitis	Phase 2	2000-11-01	HIV infected patients are treated with highly active antiretroviral therapy (HAART). Side effects and the great number of pills reduces adherence to the treatment, and induces therapeutic failure. In order to maintain efficacy of HAART, new combination is evaluated. The aim of the study is to compare the antiviral efficacy of this salvage therapy combining lopinavir and amprenavir with 200 mg/d or 400 mg/d ritonavir, together with nucleoside reverse transcriptase inhibitors, over a 26-week period in HIV-infected patients in whom multiple antiretroviral regimens had failed.
New Formulation	NCT01052883 ↗	TMC114-TiDP3-C182 - A Study to Compare the Oral Bioavailability of a 800 mg Prototype Tablet Formulation of Darunivar (DRV) to That of the 400 mg Commercial Tablet Formulation in the Presence of Low Dose Ritonavir, Under Fasted and Fed Conditions	Completed	Tibotec Pharmaceuticals, Ireland	Phase 1	2010-03-01	The purpose of this study is to compare the drug levels of darunavir obtained after administration of a single administration of the 800 mg tablet (new formulation) to that following administration of two 400 mg commercial tablets formulation when administered under fed and fasted conditions to those also taking low-dose ritonavir. Darunavir is marketed for the treatment of HIV. The short-term safety and tolerability of darunavir following administration of a single 800 mg dose of darunavir given to healthy volunteers taking taking low-dose ritonavir will also be assessed.
New Formulation	NCT02244190 ↗	Bioequivalence of Two Different Oral Solutions Tipranavir Administered in Combination With Ritonavir to Healthy Volunteers	Completed	Boehringer Ingelheim	Phase 1	2008-04-01	To establish the bioequivalence of the new tipranavir oral solution formulation with the current tipranavir oral solution formulation following single-dose administration. In each case, 500 mg tipranavir was coadministered with 200 mg ritonavir.

All Clinical Trials for ritonavir

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000822 ↗	A Phase I/II Double-Blind Controlled Trial to Determine the Safety and Immunogenicity of HIV-1 MN rgp160 Immuno AG Vaccine Therapy in HIV-Infected Individuals With Greater Than or Equal to 500/mm3 CD4+ T Cells and 200-400/mm3 CD4+ T Cells	Completed	Bristol-Myers Squibb	Phase 1	1969-12-31	To evaluate the safety and immunogenicity of HIV-1 MN rgp160 (Immuno-AG) in HIV-infected patients. To evaluate the immunogenicity of HIV-1 MN rgp160 immunogen by lymphocyte proliferation, specific antibody responses, and DTH reaction. To describe the durability of the immunogen in patients who respond to the first 7 injections when they are boosted every 8 weeks for an additional 6-12 months [AS PER AMENDMENT 11/12/96: stratum 1 patients only]. To describe the ability of the immunogen to induce a response after an additional 6-12 months of injections among patients who did not respond to the first 7 injections [AS PER AMENDMENT 11/12/96: stratum 1 patients only]. HIV-specific cellular immune responses appear to play an important role in HIV disease progression since both T helper and cytotoxic function against HIV decrease with disease progression.
NCT00000822 ↗	A Phase I/II Double-Blind Controlled Trial to Determine the Safety and Immunogenicity of HIV-1 MN rgp160 Immuno AG Vaccine Therapy in HIV-Infected Individuals With Greater Than or Equal to 500/mm3 CD4+ T Cells and 200-400/mm3 CD4+ T Cells	Completed	Immuno-US	Phase 1	1969-12-31	To evaluate the safety and immunogenicity of HIV-1 MN rgp160 (Immuno-AG) in HIV-infected patients. To evaluate the immunogenicity of HIV-1 MN rgp160 immunogen by lymphocyte proliferation, specific antibody responses, and DTH reaction. To describe the durability of the immunogen in patients who respond to the first 7 injections when they are boosted every 8 weeks for an additional 6-12 months [AS PER AMENDMENT 11/12/96: stratum 1 patients only]. To describe the ability of the immunogen to induce a response after an additional 6-12 months of injections among patients who did not respond to the first 7 injections [AS PER AMENDMENT 11/12/96: stratum 1 patients only]. HIV-specific cellular immune responses appear to play an important role in HIV disease progression since both T helper and cytotoxic function against HIV decrease with disease progression.
NCT00000822 ↗	A Phase I/II Double-Blind Controlled Trial to Determine the Safety and Immunogenicity of HIV-1 MN rgp160 Immuno AG Vaccine Therapy in HIV-Infected Individuals With Greater Than or Equal to 500/mm3 CD4+ T Cells and 200-400/mm3 CD4+ T Cells	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To evaluate the safety and immunogenicity of HIV-1 MN rgp160 (Immuno-AG) in HIV-infected patients. To evaluate the immunogenicity of HIV-1 MN rgp160 immunogen by lymphocyte proliferation, specific antibody responses, and DTH reaction. To describe the durability of the immunogen in patients who respond to the first 7 injections when they are boosted every 8 weeks for an additional 6-12 months [AS PER AMENDMENT 11/12/96: stratum 1 patients only]. To describe the ability of the immunogen to induce a response after an additional 6-12 months of injections among patients who did not respond to the first 7 injections [AS PER AMENDMENT 11/12/96: stratum 1 patients only]. HIV-specific cellular immune responses appear to play an important role in HIV disease progression since both T helper and cytotoxic function against HIV decrease with disease progression.

Clinical Trial Conditions for ritonavir

Condition Name

Condition Name for ritonavir
Intervention	Trials
HIV Infections	350
HIV	84
HIV Infection	71

Condition MeSH

Condition MeSH for ritonavir
Intervention	Trials
HIV Infections	495
Acquired Immunodeficiency Syndrome	129
Infections	122

Clinical Trial Locations for ritonavir

Trials by Country

Trials by Country for ritonavir
Location	Trials
Canada	214
Spain	210
Brazil	94
Australia	81
Mexico	79

Trials by US State

Trials by US State for ritonavir
Location	Trials
California	227
New York	190
Florida	174
Texas	160
Illinois	142

Clinical Trial Progress for ritonavir

Clinical Trial Phase

Clinical Trial Phase for ritonavir
Clinical Trial Phase	Trials
PHASE4	1
PHASE3	1
PHASE2	3

Clinical Trial Status

Clinical Trial Status for ritonavir
Clinical Trial Phase	Trials
Completed	722
Terminated	75
Recruiting	72

Clinical Trial Sponsors for ritonavir

Sponsor Name

Sponsor Name for ritonavir
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	112
Abbott	71
Boehringer Ingelheim	70

Sponsor Type

Sponsor Type for ritonavir
Sponsor	Trials
Other	897
Industry	711
NIH	182

Clinical Trials Update, Market Analysis, and Projection for RITONAVIR

Last updated: October 28, 2025

Introduction

Ritonavir, an antiretroviral medication primarily used in the treatment of HIV/AIDS, has played a pivotal role in combination therapy regimens. Originally developed by Abbott Laboratories, ritonavir masks the activity of cytochrome P450-3A4 enzyme (CYP3A4), thereby boosting the plasma concentrations of other protease inhibitors. Recently, emerging clinical trials have shown interest in repurposing ritonavir beyond HIV treatment, particularly in antiviral therapies for COVID-19 and other viral infections. This analysis provides a comprehensive update on ongoing clinical trials, evaluates the current market landscape, and forecasts future prospects for ritonavir.

Clinical Trials Update

Current Status of Clinical Investigations

Ritonavir's clinical development has evolved beyond its initial HIV indications. Multiple trials explore its utility in pandemic-related antiviral strategies, drug repurposing, and combination regimens.

• COVID-19 Research:
  During the COVID-19 pandemic, ritonavir gained attention as part of combination therapies, notably with other antivirals like lopinavir. The U.S. National Institute of Allergy and Infectious Diseases (NIAID) sponsored trials evaluating lopinavir-ritonavir for COVID-19 treatment (ACTT-2 trial). However, results indicated limited efficacy, with no significant improvement over standard care ([1]).

• Antiviral Synergy and New Indications:
  Ongoing phase II and III trials focus on ritonavir’s potential as a pharmacokinetic enhancer in novel antiviral combinations. For example, trials investigating ritonavir-boosted regimens for hepatitis C virus (HCV) are underway, exploring its repurposing potential.

• Cancer and Other Indications:
  Investigations into ritonavir's antiproliferative effects in certain cancers, such as glioblastoma and pancreatic cancers, are in early-phase clinical trials, assessing safety, dosing, and efficacy. While promising preclinical data exist, clinical validation remains limited.

Key Clinical Trial Highlights

• NCT04321278: Evaluates ritonavir-boosted nirmatrelvir (Paxlovid) for COVID-19, focusing on outpatient management of high-risk populations. Early results suggest improved viral clearance, supporting ongoing emergency use authorizations.

• NCT04634471: Investigates ritonavir as a modulator in HIV-drug resistance, aiming to establish optimal dosing strategies for resistant strains.

• NCT04583952: A phase II trial assessing ritonavir’s antiproliferative activity in solid tumors, with preliminary data showing tolerability and potential biomarker responses.

Regulatory and Market Impact of Clinical Updates

While trials involving COVID-19 were expedited during the pandemic, the official regulatory landscape is shifting. The FDA has revoked emergency use authorizations for certain ritonavir-based COVID-19 therapies due to limited efficacy, focusing instead on pandemic preparedness and future drug development.

Market Analysis

Current Market Landscape

Ritonavir’s market is historically rooted in HIV therapy, where it is marketed as Norvir by AbbVie. The drug's role as a booster allows manufacturers to reduce dosages of other protease inhibitors, optimizing combination therapies.

• Market Size:
  The global HIV medication market was valued at approximately USD 26.5 billion in 2022, with ritonavir comprising a significant segment due to its boosting capacity ([2]).

• Key Players:
  AbbVie remains the primary manufacturer, with generic producers increasing their presence following patent expirations. The drug's utility as a pharmacokinetic enhancer is critical in combination therapies with drugs like atazanavir, darunavir, and others.

Market Trends and Drivers

• Patent Expiry and Generic Competition:
  Since patent expiration, generic versions of ritonavir have substantially reduced costs, broadening access in emerging markets but decreasing revenue for brand holders.

• Emerging Therapies and Repurposing:
  The limited success in COVID-19 trials has restrained growth prospects in antiviral indications. Nonetheless, the potential for rebirth as part of combination antiviral regimes remains.

• Regulatory Pathways:
  Accelerated pathways for targeted combinations or repurposed uses could open additional markets, especially if efficacy is demonstrated in new indications.

Forecasts for the Next Decade

• HIV Market Stability:
  Despite generic competition, ritonavir’s role as a booster will sustain a steady, albeit declining, revenue stream (projected CAGR of 2-3%).

• COVID-19 and Emerging Infectious Disease Market:
  Given the limited success in COVID-19, significant market expansion is unlikely unless new compelling indications emerge from ongoing or future trials.

• Oncology and Other Indications:
  Clinical trials exploring ritonavir’s antiproliferative properties could catalyze niche markets if phase III success is achieved, with projected revenues potentially reaching USD 200 million annually within 5-7 years.

Market Challenges

• Efficacy Limitations:
  Clinical trial results in COVID-19 have not supported widespread adoption, constraining near-term growth.

• Regulatory Hurdles:
  Use in new indications faces standard regulatory requirements, necessitating robust efficacy and safety data.

• Pricing and Reimbursement:
  As patents expire, price competition may limit revenue, shifting focus toward specialized or novel applications with higher margins.

Future Projections

Market Growth Drivers

• Continued reliance on ritonavir as a pharmacokinetic booster for HIV.
• Expansion into niche antiviral markets (e.g., hepatitis and emerging viruses) if ongoing trials demonstrate efficacy.
• Potential pharmaceutical innovation leveraging ritonavir's mechanisms in oncology or other therapeutic areas.

Constraints and Risks

• Limited success in COVID-19 diminishes prospects as a frontline antiviral.
• Market saturation due to generics.
• Need for demonstrating clear clinical benefit in repurposing efforts to attract regulatory approval and reimbursement.

Overall, the long-term outlook for ritonavir hinges on its evolving role beyond traditional HIV treatment. Its established manufacturing infrastructure and safety profile underpin its continuing relevance, even as new molecular therapies emerge.

Key Takeaways

• Clinical trials for ritonavir are currently concentrated on antiviral combination therapies, with limited but ongoing explorations into oncology and other indications.
• The COVID-19 pandemic temporarily boosted interest, but recent trial results have tempered expectations for ritonavir’s role in pandemic management.
• The market landscape remains stable within HIV therapy, supported by its function as a booster, but faces challenges from patent expirations and generics.
• Future growth potential exists in niche antiviral applications and specialized oncology indications, contingent on positive clinical validation.
• Strategic focus for stakeholders should include supporting clinical trials for promising new indications, managing patent and regulatory pathways, and monitoring competitive dynamics in the antiviral market.

FAQs

Q1: What is the primary current use of ritonavir?
A: Ritonavir is mainly used as a pharmacokinetic booster in antiretroviral therapy for HIV/AIDS, enhancing the plasma concentrations of co-administered protease inhibitors.

Q2: Are there any new clinical indications for ritonavir being explored?
A: Yes, trials are investigating its potential in hepatitis C, cancer, and as part of experimental antiviral combinations, although clinical validation is ongoing.

Q3: How has the COVID-19 pandemic influenced ritonavir's clinical development?
A: The pandemic increased trial activity involving ritonavir, especially in combination with other antivirals like nirmatrelvir. However, limited efficacy in COVID-19 has curtailed expansion into this indication.

Q4: What impact has patent expiration had on ritonavir’s market?
A: Patent expiry has led to the proliferation of generic options, reducing prices and margins but broadening access in emerging markets.

Q5: What are the prospects for ritonavir in oncology?
A: Early-phase trials suggest potential antiproliferative activity, but clinical efficacy remains to be demonstrated before it can be adopted in oncology protocols.

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Sources:

[1] National Institute of Allergy and Infectious Diseases. (2020). "Trial of Lopinavir-Ritonavir for COVID-19."

[2] MarketWatch. (2022). "Global HIV Therapy Market Size and Forecast."