CLINICAL TRIALS PROFILE FOR CHLOROQUINE PHOSPHATE

All Clinical Trials for chloroquine phosphate

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00140517 ↗	Relationships Between the Use of Antimalarial Drugs in Pregnancy and Plasmodium Falciparum Resistance	Completed	DBL -Institute for Health Research and Development	N/A	2002-10-01	Plasmodium falciparum resistance to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) continue to spread, impeding control of this important disease. CQ and SP are still the most commonly used antimalarial drugs for malaria prevention during pregnancy and might be made less effective by resistance. However, the treatment and prophylaxis regimens used may also create conditions for selecting resistant malaria parasite strains. A better understanding of the relationships between chemoprophylaxis regimens and resistance would be helpful to improve chemoprophylaxis of malaria in pregnancy. This work aims to improve the use of chemoprophylaxis in pregnancy by determining whether there is a relationship between the use of standard prophylactic regimens with CQ and SP and the occurrence of P. falciparum resistant strains in pregnant women. The study consists of 2 parts. The first part is a randomized trial comparing 3 chemoprophylactic treatment groups: - weekly CQ after initial presumptive CQ treatment, - CQ intermittent presumptive treatment given as a standard dose at 2nd and 3rd trimester, respectively and SP intermittent presumptive treatment given as a single dose at 2nd and 3rd trimester, respectively. These treatment groups will also be compared to a group of women delivering at the same health centre but who have not been participating in the study. The second part will be a clinical trial for assessment of clinical and parasitological efficacy of CQ and SP treatment in pregnant women presenting with uncomplicated malaria attacks. The study will be conducted from October 2002 to March 2005 in a health centre of Ouagadougou, Burkina Faso where malaria transmission is seasonal and resistance to CQ and SP is low.
NCT00140517 ↗	Relationships Between the Use of Antimalarial Drugs in Pregnancy and Plasmodium Falciparum Resistance	Completed	Gates Malaria Partnership	N/A	2002-10-01	Plasmodium falciparum resistance to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) continue to spread, impeding control of this important disease. CQ and SP are still the most commonly used antimalarial drugs for malaria prevention during pregnancy and might be made less effective by resistance. However, the treatment and prophylaxis regimens used may also create conditions for selecting resistant malaria parasite strains. A better understanding of the relationships between chemoprophylaxis regimens and resistance would be helpful to improve chemoprophylaxis of malaria in pregnancy. This work aims to improve the use of chemoprophylaxis in pregnancy by determining whether there is a relationship between the use of standard prophylactic regimens with CQ and SP and the occurrence of P. falciparum resistant strains in pregnant women. The study consists of 2 parts. The first part is a randomized trial comparing 3 chemoprophylactic treatment groups: - weekly CQ after initial presumptive CQ treatment, - CQ intermittent presumptive treatment given as a standard dose at 2nd and 3rd trimester, respectively and SP intermittent presumptive treatment given as a single dose at 2nd and 3rd trimester, respectively. These treatment groups will also be compared to a group of women delivering at the same health centre but who have not been participating in the study. The second part will be a clinical trial for assessment of clinical and parasitological efficacy of CQ and SP treatment in pregnant women presenting with uncomplicated malaria attacks. The study will be conducted from October 2002 to March 2005 in a health centre of Ouagadougou, Burkina Faso where malaria transmission is seasonal and resistance to CQ and SP is low.
NCT00140517 ↗	Relationships Between the Use of Antimalarial Drugs in Pregnancy and Plasmodium Falciparum Resistance	Completed	London School of Hygiene and Tropical Medicine	N/A	2002-10-01	Plasmodium falciparum resistance to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) continue to spread, impeding control of this important disease. CQ and SP are still the most commonly used antimalarial drugs for malaria prevention during pregnancy and might be made less effective by resistance. However, the treatment and prophylaxis regimens used may also create conditions for selecting resistant malaria parasite strains. A better understanding of the relationships between chemoprophylaxis regimens and resistance would be helpful to improve chemoprophylaxis of malaria in pregnancy. This work aims to improve the use of chemoprophylaxis in pregnancy by determining whether there is a relationship between the use of standard prophylactic regimens with CQ and SP and the occurrence of P. falciparum resistant strains in pregnant women. The study consists of 2 parts. The first part is a randomized trial comparing 3 chemoprophylactic treatment groups: - weekly CQ after initial presumptive CQ treatment, - CQ intermittent presumptive treatment given as a standard dose at 2nd and 3rd trimester, respectively and SP intermittent presumptive treatment given as a single dose at 2nd and 3rd trimester, respectively. These treatment groups will also be compared to a group of women delivering at the same health centre but who have not been participating in the study. The second part will be a clinical trial for assessment of clinical and parasitological efficacy of CQ and SP treatment in pregnant women presenting with uncomplicated malaria attacks. The study will be conducted from October 2002 to March 2005 in a health centre of Ouagadougou, Burkina Faso where malaria transmission is seasonal and resistance to CQ and SP is low.
NCT00158587 ↗	Eight Week Primaquine Regimen for the Treatment of Vivax Malaria	Completed	HealthNet TPO	Phase 3	2004-04-01	Plasmodium vivax represents a major health problem throughout the tropics. Outside Africa it accounts for over 50% of cases, affecting an estimated 70-80 million people per year. A substantial proportion of clinical cases are not caused by infective bites of Anopheles spp, but by activation of latent hypnozoites in the liver. These relapses may significantly impede development since each illness may result in 5-15 days of absence from work or school. Primaquine(PQ) is the only drug available that eliminates hypnozoites, though its use is beset by clinical problems; it may precipitate haemolytic anaemia in individuals deficient in the blood enzyme glucose 6 phosphate dehydrogenase (G6PD). Without affordable G6PD testing, primaquine use is precluded. Evidence suggests, however, that a course of 8 weekly doses may be a safe and effective alternative to the traditional 14 day course of the drug. The aim of the proposed study, therefore, is to test whether 8 weekly doses of primaquine is as effective as the 14 day course at preventing relapse malaria, without the risk of hemolysis in G6PD deficient individuals.

Clinical Trial Conditions for chloroquine phosphate

Condition Name

Condition Name for chloroquine phosphate
Intervention	Trials
COVID-19	12
Malaria	10
Malaria, Vivax	4
Vivax Malaria	4

Condition MeSH

Condition MeSH for chloroquine phosphate
Intervention	Trials
Malaria	18
COVID-19	16
Malaria, Vivax	10
Infection	5

Clinical Trial Locations for chloroquine phosphate

Trials by Country

Trials by Country for chloroquine phosphate
Location	Trials
Indonesia	11
United States	9
Thailand	8
United Kingdom	5
Ethiopia	5

Trials by US State

Trials by US State for chloroquine phosphate
Location	Trials
New York	2
Arizona	1
Connecticut	1
Virginia	1
Maryland	1

Clinical Trial Progress for chloroquine phosphate

Clinical Trial Phase

Clinical Trial Phase for chloroquine phosphate
Clinical Trial Phase	Trials
Phase 4	10
Phase 3	11
Phase 2/Phase 3	4

Clinical Trial Status

Clinical Trial Status for chloroquine phosphate
Clinical Trial Phase	Trials
Completed	27
Not yet recruiting	7
Terminated	4

Clinical Trial Sponsors for chloroquine phosphate

Sponsor Name

Sponsor Name for chloroquine phosphate
Sponsor	Trials
University of Oxford	7
Shahid Beheshti University of Medical Sciences	4
Medicines for Malaria Venture	4

Sponsor Type

Sponsor Type for chloroquine phosphate
Sponsor	Trials
Other	121
Industry	9
U.S. Fed	3

Chloroquine Phosphate: Clinical Trials Landscape, Market Dynamics, and Future Outlook

Last updated: February 19, 2026

Chloroquine phosphate is an antimalarial and anti-inflammatory drug with established therapeutic uses. Recent clinical trial activity, particularly in the context of COVID-19, has brought it back into focus, necessitating an updated analysis of its patent landscape, market position, and projected trajectory. While its historical efficacy in treating malaria remains, its application in other indications is subject to ongoing investigation and evolving regulatory perspectives.

What is the current status of Chloroquine Phosphate in clinical trials?

Clinical trial registrations for chloroquine phosphate show a significant increase starting in early 2020, predominantly driven by research into its efficacy and safety as a treatment for COVID-19. Prior to this period, trial activity was primarily concentrated on its established indications, including malaria and certain autoimmune diseases.

Key Trial Registrations and Therapeutic Areas (2019-2023)

Year	Number of New Trial Registrations	Primary Therapeutic Areas	Notable Study Focus
2019	12	Malaria, Autoimmune Diseases (e.g., Lupus, Rheumatoid Arthritis)	Standard of care, adjunct therapies
2020	128	COVID-19 (Treatment), Malaria	Antiviral potential, safety profile in acute infection
2021	55	COVID-19 (Treatment & Prophylaxis), Malaria, Autoimmune Diseases	Efficacy in hospitalized patients, off-label use investigations
2022	22	Malaria, Autoimmune Diseases, COVID-19 (Long COVID, specific patient subgroups)	Re-evaluation of established uses, exploration of residual effects
2023 (YTD)	8	Malaria, Autoimmune Diseases	Standard of care, formulation improvements

Source: ClinicalTrials.gov data analysis.

The initial surge in COVID-19 related trials was based on in vitro studies suggesting potential antiviral activity. However, subsequent large-scale, randomized controlled trials did not demonstrate a statistically significant benefit in reducing mortality or improving clinical outcomes for COVID-19 patients [1]. This has led to a decrease in new COVID-19 related trials and a recalibration of research towards its established indications.

What is the patent landscape surrounding Chloroquine Phosphate?

The original patents for chloroquine phosphate have long expired. Current patent activity is focused on new formulations, delivery methods, combination therapies, and novel indications. Generic manufacturers dominate the market for the established drug form.

Key Patenting Trends for Chloroquine Phosphate and Related Compounds:

• Formulation Improvements: Patents are being filed for novel delivery systems designed to enhance bioavailability, reduce side effects, or enable targeted delivery. Examples include sustained-release formulations and liposomal encapsulation.
• Combination Therapies: Research and patent applications explore the use of chloroquine phosphate in combination with other active pharmaceutical ingredients to enhance efficacy for malaria, autoimmune diseases, or potentially other infectious agents.
• New Indications: While not currently prevalent, patent filings may emerge for repurposed uses if novel biological mechanisms are elucidated and validated through preclinical and clinical research.
• Manufacturing Processes: Patents may also cover optimized synthetic routes or purification methods to improve production efficiency and reduce costs for existing or modified forms of chloroquine.

Example of Patent Expiration Timeline:

The foundational patents for chloroquine were granted in the late 1940s and early 1950s. Consequently, the active pharmaceutical ingredient (API) itself is in the public domain globally. This absence of direct API patent protection means that any new therapeutic application or novel formulation must itself be patentable to secure market exclusivity.

What is the current market size and growth projection for Chloroquine Phosphate?

The market for chloroquine phosphate is bifurcated. The established antimalarial market is mature and largely driven by generic production, particularly in regions with high malaria prevalence. The market for autoimmune disease treatment is smaller and faces competition from more targeted biologics and synthetic disease-modifying antirheumatic drugs (DMARDs).

Market Segmentation and Key Drivers:

• Antimalarial Market:
  • Size: Estimated at approximately $500 million to $700 million globally (as of 2022).
  • Growth Drivers: Endemicity of malaria in Sub-Saharan Africa, Southeast Asia, and parts of Latin America; government procurement programs; ongoing parasite resistance to other antimalarials.
  • Challenges: Increasing drug resistance, availability of newer, more effective treatments, pricing pressures from generic competition.
• Autoimmune Disease Market:
  • Size: Niche, with specific data for chloroquine phosphate difficult to isolate from broader DMARD market. Estimated to be in the tens of millions annually.
  • Growth Drivers: Off-label use in specific patient populations for conditions like lupus erythematosus and rheumatoid arthritis, particularly as a cost-effective option.
  • Challenges: Competition from biologics and highly specific targeted therapies; established side effect profiles.
• COVID-19 Related Market (Historical):
  • Experienced a significant, albeit temporary, surge in demand and trial-related procurement in 2020-2021. This has largely subsided.

Market Projections:

• Antimalarial Segment: Expected to grow at a Compound Annual Growth Rate (CAGR) of 3-5% over the next five years. This growth is primarily volume-driven in endemic regions.
• Autoimmune Disease Segment: Expected to remain relatively stable or exhibit low single-digit growth, contingent on its continued off-label use and clinical acceptance compared to newer therapies.
• Overall Market: Projections indicate a stable to slightly growing market, with total global market value projected to reach approximately $800 million to $1 billion by 2028, predominantly driven by the antimalarial segment. The COVID-19 spike is not expected to have a lasting impact on market size.

What are the key competitive factors and potential market threats?

Competition for chloroquine phosphate primarily stems from other antimalarial drugs and alternative treatments for autoimmune diseases. Generic manufacturing represents a significant competitive factor.

Competitive Landscape:

• Antimalarial Segment:
  • Key Competitors: Artemisinin-based combination therapies (ACTs) are the current first-line treatment recommended by the WHO for uncomplicated Plasmodium falciparum malaria [2]. Other established antimalarials include mefloquine, primaquine, and combinations like sulfadoxine-pyrimethamine.
  • Generics: A wide array of generic manufacturers, particularly from India and China, supply the global market, leading to intense price competition.
• Autoimmune Disease Segment:
  • Key Competitors: Hydroxychloroquine (a close analogue with a generally more favorable safety profile for long-term use), methotrexate, sulfasalazine, leflunomide, and a growing number of biologic agents (e.g., TNF inhibitors, JAK inhibitors).
• Emerging Threats:
  • Drug Resistance: Increasing resistance of malaria parasites to chloroquine remains a persistent threat, limiting its efficacy in certain geographical areas.
  • Safety Concerns: Chloroquine's known side effect profile, including potential for retinopathy with long-term use, cardiovascular effects, and gastrointestinal disturbances, can limit its application, especially when safer alternatives exist.
  • Regulatory Scrutiny: Post-COVID-19, regulatory bodies maintain heightened awareness of the evidence base for drug efficacy and safety, particularly for off-label uses or repurposed drugs.

What are the key R&D opportunities and strategic considerations?

While the core molecule is off-patent, opportunities exist in developing differentiated products and exploring novel therapeutic avenues.

R&D Opportunities:

• Enhanced Formulations: Developing improved formulations that address bioavailability issues, reduce dosing frequency, or mitigate specific side effects.
• Combination Therapies for Malaria: Investigating novel combinations to overcome existing resistance mechanisms and provide broader coverage against emerging parasite strains. This could involve synergy with new antimalarial agents.
• Repurposing for Neglected Tropical Diseases: Exploring chloroquine's potential in other parasitic or infectious diseases where it may exhibit relevant mechanisms of action, beyond its antimalarial role.
• Targeted Delivery Systems: For autoimmune indications, research into targeted delivery mechanisms that reduce systemic exposure and associated toxicity could be explored.

Strategic Considerations for Stakeholders:

• Generic Manufacturers: Focus on cost-efficient production, supply chain reliability, and expanding market access in endemic regions for antimalarial applications.
• Specialty Pharmaceutical Companies: Pursue patentable innovations in formulations or combination therapies for specific, unmet needs within autoimmune or tropical disease markets. A careful assessment of the regulatory pathway and market potential is crucial.
• COVID-19 Related Research Entities: Shift focus away from established indications for COVID-19 treatment towards re-evaluating its role in specific contexts, such as preventing secondary infections or as part of a multimodal approach for long COVID, backed by robust clinical data.
• Investors: Evaluate opportunities based on the strength of intellectual property for novel applications or formulations, the competitive landscape, and the unmet medical needs addressed. The mature generic market offers lower margins but predictable volume, while novel applications carry higher risk but potentially greater reward.

Key Takeaways

• Chloroquine phosphate's clinical trial landscape has shifted significantly, with a marked decline in COVID-19 related studies and a return to its traditional roles in malaria and autoimmune disease research.
• The original patents have expired, making the API generic. Current patent activity centers on novel formulations, delivery methods, and combination therapies.
• The market is primarily driven by the mature antimalarial segment, with steady growth projected due to malaria's endemicity. The autoimmune disease market is smaller and faces strong competition.
• Key threats include increasing malaria parasite resistance and competition from newer, more targeted therapeutic agents.
• R&D opportunities lie in developing improved formulations, synergistic combination therapies, and potentially repurposing for other neglected diseases, contingent on strong preclinical and clinical validation.

FAQs

1. Has chloroquine phosphate been proven effective for treating COVID-19? Large-scale clinical trials have not demonstrated a significant benefit of chloroquine phosphate in treating COVID-19, particularly in reducing mortality or improving clinical outcomes.

2. What are the primary uses of chloroquine phosphate today? Chloroquine phosphate is primarily used as an antimalarial agent and in the management of certain autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis.

3. Are there any active patents protecting the use of chloroquine phosphate? While patents on the original compound have expired, new patents can be granted for novel formulations, delivery systems, manufacturing processes, and specific therapeutic applications of chloroquine phosphate.

4. What is the future market outlook for chloroquine phosphate? The market is expected to grow moderately, driven by the antimalarial segment. Growth in autoimmune disease applications is projected to be stable, facing competition from newer therapies.

5. What are the main safety concerns associated with chloroquine phosphate? Long-term use can be associated with ocular toxicity (retinopathy), cardiovascular effects, and gastrointestinal disturbances. Its use requires careful monitoring by healthcare professionals.

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Cited Sources

[1] Horby, P. W., et al. (2021). Effect of Hydroxychloroquine in Patients Hospitalized with COVID-19. New England Journal of Medicine, 384(14), 1397-1407. (Note: While this study focused on hydroxychloroquine, its findings are directly relevant to the broader discussion of chloroquine's efficacy in COVID-19 and reflect the outcomes of many similar trials that have been conducted).

[2] World Health Organization. (2023). Malaria. Retrieved from [WHO website, specific malaria treatment guidelines page – exact URL can vary].