CLINICAL TRIALS PROFILE FOR DARAPRIM

All Clinical Trials for DARAPRIM

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00065390 ↗	Pyrimethamine to Treat Autoimmune Lymphoproliferative Syndrome	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	2003-07-01	This study will examine whether the drug pyrimethamine can shrink lymph nodes and spleen in patients with autoimmune lymphoproliferative syndrome (ALPS). In this disease, lymphocytes (white blood cells) do not die as they normally would. As a result, patients have enlarged lymph glands, spleen, or liver, and other problems that may involve blood cell counts and autoimmune disease (overactivity of the immune system). Pyrimethamine is an orally administered antibiotic that has been used to treat or prevent malaria and toxoplasma, and may be effective in shrinking lymph nodes and spleen. Patients with ALPS who are between 2 and 70 years of age and have had lymph gland enlargement for at least 1 year may be eligible for this study. Candidates will be screened with a medical history and physical examination, blood tests, and possibly a bone marrow test. Females of reproductive age will be screened with a urine pregnancy test. Women who are capable of becoming pregnant must use an effective method of birth control during the entire study period, because, taken during early months of pregnancy, pyrimethamine can cause birth defects in the fetus. Women who are pregnant or nursing are excluded from the study. Participants will undergo the following tests and procedures: - CT scan: For this test, the patient lies still in the CT scanner while images are taken of the neck, chest, and stomach area. A contrast dye is injected into a vein to brighten the CT images. Very young children will be evaluated on a case by case basis to determine whether a CT scan will be performed. - Bone marrow biopsy: Participants undergo this test to rule out underlying bone marrow disease if they have not had a bone marrow test done in the last six months prior to enrolling in pyrimethamine study, as pyrimethamine can affect bone marrow function. Under local anesthesia, a needle is inserted into the back part of the hipbone and a small amount of marrow is removed. (Children are sedated for this test.) - Leukapheresis: This is a procedure for collecting a small proportion of circulating white blood cells while conserving the majority of blood cells. Specifically, blood is drawn from a needle placed in an arm vein and is directed into a cell separator machine, which separates the blood cells by spinning. A small proportion of circulating white cells are removed, and the red cells, platelets, plasma and majority of white cells are returned to the patient's blood circulation. Only patients who are 7 years of age or older and weigh at least 55 pounds undergo this procedure. Other participants who choose not to have apheresis will have about 3 tablespoons of blood drawn instead. - Pyrimethamine administration: When the above tests are completed, participants begin taking pyrimethamine. The dose is determined according to the individual's weight and is gradually increased during the study period. Patients take the drug twice a week for a total of 12 weeks. - Blood tests: Blood samples are collected during weeks 2, 4, 6, 8, and 10 after beginning treatment, and 2 weeks after the last dose of pyrimethamine. The purpose of these blood tests is to check for possible drug-related side effects. Patients who develop a skin rash, mouth sores or other side effects may have one or more doses of the treatment drug withheld. When indicated, the patient will be directed to stop taking the study drug. If needed, drug side effects will be treated with a vitamin supplement, folinic acid, taken by mouth, 3 times weekly. - Evaluations at the NIH Clinical Center will comprise of a pretreatment visit, one end of treatment visit at the end of 12 weeks and an optional post-treatment visit 3months after stopping pyrimethamine therapy. Patients who respond well to treatment may be asked to return to NIH for additional visits at 3, 6, and 12 months after the treatment has ended for repeat evaluations. If their lymph glands or spleen become much larger after stopping pyrimethamine, they will be offered treatment for another 12 weeks. If they respond to the second course of treatment, they will return to NIH again after 3, 6, and 12 months. If the symptoms return again, patients will be asked to resume treatment for an additional 6 months or more. They will have blood drawn periodically by their private physician and will return to NIH for evaluation every 12 weeks.
NCT00300404 ↗	Effect of Specific Anti-Toxoplasmatic Add-on Medication in Toxoplasma Gondii Seropositive Individuals With Schizophrenia or Major Depression	Completed	Stanley Medical Research Institute	Phase 3	2002-01-01	We investigate whether the add-on specific antitoxoplasmatic medication has positive effects in individuals with schizophrenia or major depression seropositive for Toxoplasma gondii (TG) infection. As TG modulates neurotransmitter metabolism affecting serotonin and dopamine we hypothesize that this chronic persistent infection might play a role for depressive and psychotic symptomatology. Therefore, on the basis of an ex juvantibus approach, specific anti TG medication might further improve psychiatric symptomatology in affected patients. This is investigated in a double-blind, placebo-controlled, randomized treatment trial.
NCT00300404 ↗	Effect of Specific Anti-Toxoplasmatic Add-on Medication in Toxoplasma Gondii Seropositive Individuals With Schizophrenia or Major Depression	Completed	Zentrum für Integrative Psychiatrie	Phase 3	2002-01-01	We investigate whether the add-on specific antitoxoplasmatic medication has positive effects in individuals with schizophrenia or major depression seropositive for Toxoplasma gondii (TG) infection. As TG modulates neurotransmitter metabolism affecting serotonin and dopamine we hypothesize that this chronic persistent infection might play a role for depressive and psychotic symptomatology. Therefore, on the basis of an ex juvantibus approach, specific anti TG medication might further improve psychiatric symptomatology in affected patients. This is investigated in a double-blind, placebo-controlled, randomized treatment trial.
NCT01066663 ↗	Pyrimethamine for the Treatment of Relapsed Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma	Recruiting	Beth Israel Deaconess Medical Center	Phase 1/Phase 2	2010-03-01	In this research study we will start by looking for the highest dose of pyrimethamine that can be given safely to CLL patients without severe or unmanageable side effects. This dose will then be used for a larger Phase II study to assess the efficacy of pyrimethamine for the treatment of CLL/SLL. Pyrimethamine is an antibiotic that is used for the treatment of certain infections. Previous research studies have shown that pyrimethamine may target a protein in tumor cells, called STAT3, which may be important for the growth of chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) cells. Pyrimethamine can kill CLL/SLL cells in the laboratory, and we are therefore undertaking this study to assess whether pyrimethamine will result in clinical benefit or tumor responses in CLL in patients.
NCT01066663 ↗	Pyrimethamine for the Treatment of Relapsed Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma	Recruiting	Brigham and Women's Hospital	Phase 1/Phase 2	2010-03-01	In this research study we will start by looking for the highest dose of pyrimethamine that can be given safely to CLL patients without severe or unmanageable side effects. This dose will then be used for a larger Phase II study to assess the efficacy of pyrimethamine for the treatment of CLL/SLL. Pyrimethamine is an antibiotic that is used for the treatment of certain infections. Previous research studies have shown that pyrimethamine may target a protein in tumor cells, called STAT3, which may be important for the growth of chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) cells. Pyrimethamine can kill CLL/SLL cells in the laboratory, and we are therefore undertaking this study to assess whether pyrimethamine will result in clinical benefit or tumor responses in CLL in patients.
NCT01066663 ↗	Pyrimethamine for the Treatment of Relapsed Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma	Recruiting	Lymphoma Research Foundation	Phase 1/Phase 2	2010-03-01	In this research study we will start by looking for the highest dose of pyrimethamine that can be given safely to CLL patients without severe or unmanageable side effects. This dose will then be used for a larger Phase II study to assess the efficacy of pyrimethamine for the treatment of CLL/SLL. Pyrimethamine is an antibiotic that is used for the treatment of certain infections. Previous research studies have shown that pyrimethamine may target a protein in tumor cells, called STAT3, which may be important for the growth of chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) cells. Pyrimethamine can kill CLL/SLL cells in the laboratory, and we are therefore undertaking this study to assess whether pyrimethamine will result in clinical benefit or tumor responses in CLL in patients.

Clinical Trial Conditions for DARAPRIM

Condition Name

Condition Name for DARAPRIM
Intervention	Trials
Myelodysplastic Syndromes	1
Autoimmune Disease	1
Schizophrenia	1
Cancer of the Head and Neck	1

Condition MeSH

Condition MeSH for DARAPRIM
Intervention	Trials
Autoimmune Lymphoproliferative Syndrome	1
Squamous Cell Carcinoma of Head and Neck	1
Schizophrenia	1
Sclerosis	1

Clinical Trial Locations for DARAPRIM

Trials by Country

Trials by Country for DARAPRIM
Location	Trials
United States	6
Sweden	1
Italy	1
Netherlands	1
Germany	1

Trials by US State

Trials by US State for DARAPRIM
Location	Trials
New York	2
Missouri	1
Texas	1
Massachusetts	1
Maryland	1

Clinical Trial Progress for DARAPRIM

Clinical Trial Phase

Clinical Trial Phase for DARAPRIM
Clinical Trial Phase	Trials
Phase 3	1
Phase 1/Phase 2	3
Phase 1	3

Clinical Trial Status

Clinical Trial Status for DARAPRIM
Clinical Trial Phase	Trials
Completed	5
Not yet recruiting	1
Recruiting	1

Clinical Trial Sponsors for DARAPRIM

Sponsor Name

Sponsor Name for DARAPRIM
Sponsor	Trials
Montefiore Medical Center	2
Seoul National University Hospital	1
Albert Einstein College of Medicine	1

Sponsor Type

Sponsor Type for DARAPRIM
Sponsor	Trials
Other	15
NIH	1

Last updated: May 20, 2026

Daraprim (pyrimethamine) Clinical Trials Update, Market Analysis, and Market Projection (US and Selected Ex-US)

Daraprim (pyrimethamine) is an established off-patent antiprotozoal with no current late-stage proprietary clinical development pipeline in the public domain sufficient to support a full “clinical trials update” for investors. The market is characterized by intermittent, supply-driven demand dynamics and episodic public-health or parasitology use-cases, with pricing and procurement influenced by specialty drug access, compounded alternatives, and hospital formularies. Near-term commercial visibility is constrained by the drug’s long lifecycle and the absence of identifiable, ongoing Phase 3 or registrational studies leading to new indications.

What is Daraprim used for and why does demand stay volatile?

Daraprim (pyrimethamine) is marketed for parasitic infections including toxoplasmosis (often in combination regimens, historically with sulfadiazine) and certain malaria regimens in specific settings. Utilization is lumpy because it depends on:

• Clinical guideline positioning (combination with other agents; not typically first-line monotherapy).
• Indication-specific patient populations (HIV-related toxoplasmosis prophylaxis, congenital toxoplasmosis in historical regimens, and other niche parasitology uses).
• Stocking patterns for hospitals and ID programs.
• Supply continuity, since small-molecule manufacturing scale and specialty distribution can drive shortfalls that temporarily move pricing and allocation.

Who sells Daraprim and what is the current regulatory posture?

Daraprim is an FDA-approved drug. The US commercial product is generally treated as mature and not growth-oriented. Public Orange Book-driven exclusivity and patent term analysis cannot be completed here to the level required for litigation-grade projections because the needed Orange Book record set (listed drug, NDCs, all patents with expiration/launch-impact dates) is not provided in this prompt.

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What do current clinical trials for Daraprim show (Phase 1 to Phase 3)?

Featured snippet answer: No robust, ongoing late-stage (Phase 2/3) Daraprim registrational trials with publicly disclosed results or trial-completion timelines are available in the provided inputs to support a credible “clinical trials update.”

H3: Are there any published Daraprim trials in toxoplasmosis, malaria, or other parasitology indications?

Public sources commonly show:

• Older toxoplasmosis management evidence sets.
• Limited modern trials because pyrimethamine is off-patent and often substituted within combination protocols or replaced by other agents when available and guideline-supported.

Without identifiable active trials tied to Daraprim’s current branded product lifecycle, the best-supported clinical “update” is that Daraprim functions as a mature, guideline-supported medicine where incremental clinical evidence is less likely to change market share materially.

H3: What would count as a market-moving clinical update?

Market-moving updates would be:

• Registrational trials for a new indication or new formulation leading to label expansion.
• Trials establishing a new combination that changes standard-of-care.
• Pharmacokinetic or resistance data supporting updated malaria use where it could replace alternatives.

No such publicly anchored updates are provided here.

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How big is the Daraprim market and which segments drive demand?

Featured snippet answer: Demand concentrates in toxoplasmosis management and specific parasitology use patterns, with sales influenced by acute availability and institutional procurement cycles rather than a continuous, high-growth prescriber base.

H3: Segment map (high level, US-centric with global spillovers)

• Toxoplasmosis in immunocompromised patients (historically HIV-associated).
• Congenital/ocular toxoplasmosis regimens in selected settings where pyrimethamine remains used in combinations.
• Malaria (in certain geographies or resistant-pattern contexts where pyrimethamine-containing regimens are used historically or selectively).

H3: What allocation and procurement dynamics do to quarterly sales?

Because the drug is off-patent and niche:

• Shortages can spike demand and reorder urgency.
• When multiple supply sources exist (or compounded/alternative regimens become available), branded sales can soften quickly.
• Hospital formularies can reduce use if alternative antiprotozoals have become guideline-favored.

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What is the Daraprim pricing and reimbursement landscape (and how does it affect projections)?

Featured snippet answer: Branded pricing and reimbursement for off-patent, mature specialty drugs tend to be shaped by supply, specialty distribution, and payer-specific coverage rather than patent-driven commercial protection.

H3: Key commercial sensitivities

• Specialty pharmacy distribution channel economics.
• Reimbursement by indication and regimen.
• Wholesale acquisition cost and net price compression where generics or alternative products exist.
• Substitution by combination regimens with different cost structures.

Because no current NDC-level pricing or payer trend data is supplied, a quantified US net sales model cannot be produced here at an investment-grade level.

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When does Daraprim lose exclusivity and what patent estate controls generics risk?

Featured snippet answer: Daraprim’s core product is widely regarded as off-patent; a complete exclusivity and patent-coverage audit (including Orange Book listed patents, expiration dates, and exclusivity periods) cannot be generated from the information in this prompt.

H3: What matters for generic or alternative competition

For a mature small molecule like pyrimethamine:

• Orange Book listed patents (drug substance, composition, formulation, and method-of-use).
• Any exclusivity tied to changes in labeling or formulations.
• Litigation or settlement agreements that delay generic entry (if any).

No listing-level data is included in the prompt, so a precise “when exclusivity ends” answer is not deliverable here.

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What generic entry risks exist for Daraprim (ANDA, Paragraph IV)?

Featured snippet answer: Generic risk exists structurally for off-patent drugs, but the specific Paragraph IV activity, if any, cannot be confirmed without Orange Book and litigation dockets tied to the listed drug(s).

H3: What would trigger a near-term share shift?

• New generic launches on specific NDCs.
• Shortage-driven allocation corrections.
• Label or safety communications that alter prescribing patterns.

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How does Daraprim compare with alternatives for toxoplasmosis and malaria (market share impact)?

Featured snippet answer: Market share is strongly influenced by guideline preference and regimen selection for toxoplasmosis and by alternative antimalarials in malaria, with pyrimethamine’s role often being combination-anchored and sensitive to availability.

H3: Toxoplasmosis regimen substitution dynamics

In clinical practice, pyrimethamine has historically been used in combination regimens. If alternatives or updated regimens become favored, branded utilization can decline even without a legal exclusivity change.

H3: Malaria regimen substitution dynamics

Malaria treatment selection depends on geography, resistance patterns, and guideline changes. Pyrimethamine-based regimens can lose use when other antimalarials dominate procurement.

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What FDA status does Daraprim have (Orange Book listings, exclusivity, labeling changes)?

Featured snippet answer: Daraprim is FDA-approved; a current Orange Book listing breakdown (patent numbers, expiration dates, dosage-form coverage) cannot be produced from the prompt inputs.

H3: What would be required for an Orange Book-grade market risk score?

• Listed drug identification (US label product and NDC mapping).
• All Orange Book patents and their listed expiration dates.
• Any pediatric exclusivity, 505(b)(2) exclusivity, or other exclusivity events tied to the approval history.

No Orange Book record set is included here.

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Commercial projection for Daraprim: base case, bull case, bear case

Featured snippet answer: Without current sales base, channel share, NDC-level pricing, and supply data, a quantified projection cannot be computed in a defensible way. Qualitatively, outcomes are likely to track (1) institutional toxoplasmosis demand and (2) supply continuity, with modest structural growth and episodic swings.

Base case (most likely)

• Stable toxoplasmosis-related demand with limited expansion.
• No new label expansion.
• Sales mainly track institutional procurement and supply consistency.

Bull case (upside drivers)

• Supply constraints affecting alternatives that increase pyrimethamine utilization.
• Broader guideline or formulary acceptance in specific settings where pyrimethamine remains a core combination partner.
• Reduced substitution due to shortages or access issues with comparators.

Bear case (downside drivers)

• Increased reliance on alternative regimens for toxoplasmosis and/or antimalarials.
• More competitive net pricing via increased generic availability.
• Distribution or manufacturing continuity issues that cap supply and reduce fill rates.

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Key data table: What to model for Daraprim revenue sensitivity

Driver	Direction of impact on sales	How it shows up in quarters
Hospital/institution toxoplasmosis demand	Positive	Reorders, stable baseline
Competition via generics/alternatives	Negative	Net price compression, volume shift
Supply continuity (brand availability)	Positive	Allocation-driven spikes or improved fills
Guideline/regimen shifts	Negative (often)	Step-down in monthly usage
Payer reimbursement	Mixed	Coverage changes by indication

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Key Takeaways

• Daraprim is a mature antiprotozoal with market behavior driven less by clinical trial catalysts and more by guideline use, regimen selection, and supply continuity.
• A complete “clinical trials update” with Phase 2/3 registrational milestones cannot be supported from the prompt inputs.
• A quantified market projection requires current sales baselines, NDC-level pricing, supply constraints, and competition mapping; such inputs are not provided here.
• Investment and commercial planning should treat Daraprim as a specialty access and procurement-sensitive product rather than a growth pipeline story.

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FAQs

1. What conditions drive most Daraprim prescriptions in the US?
2. Do toxoplasmosis treatment guidelines still recommend pyrimethamine combination regimens?
3. How does generic availability of pyrimethamine affect Daraprim net sales?
4. What supply or manufacturing events most commonly change Daraprim availability?
5. Are there any new formulations or delivery-system developments for pyrimethamine that could impact demand?

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References

1. FDA Orange Book: Drug Products (Approved Drug Products with Therapeutic Equivalence Evaluations). US Food and Drug Administration.
2. ClinicalTrials.gov. Daraprim / pyrimethamine.