CLINICAL TRIALS PROFILE FOR PRILOSEC

505(b)(2) Clinical Trials for PRILOSEC

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
OTC	NCT00746733 ↗	Vyvanse and Adderall XR Given Alone and in Combination With Prilosec OTC	Completed	Shire	Phase 1	2008-09-08	The purpose of this study is to determine if taking Vyvanse with Prilosec OTC or Adderall XR with Prilosec OTC changes how quickly the drug is absorbed into the body and/or changes how much of the drug is absorbed into the body.
OTC	NCT01077076 ↗	Pharmacodynamic Study Comparing the Effects of Two Different Forms of Omeprazole (P07812) (COMPLETED)	Completed	Bayer	Phase 3	2008-12-01	This randomized, crossover study is to evaluate the early effectiveness, defined as effect on intragastric pH during the first 4 hours after dosing, of Zegerid, Prilosec over-the-counter (OTC) Tablets, and placebo on the 4th day of treatment to inhibit acid secretion. Additional purposes are to: 1. provide pharmacodynamic evidence comparing 24-hr inhibition of acid secretion on the 1st, 4th, and 11th days of dosing with each of the indicated treatments; 2. compare Zegerid and Prilosec OTC for achieving their steady-state effects for controlling 24-hr gastric acidity at steady-state on the 4th and 11th day of dosing. 3. evaluate early effectiveness, defined as effect on intragastric pH during the first 4 hours after administration, of Zegerid, Prilosec OTC Tablets, and placebo on acid inhibition at steady-state when administered on the 11th day of dosing.
OTC	NCT01122160 ↗	Gastric pH and Anthocyanin Absorption	Completed	USDA Beltsville Human Nutrition Research Center	N/A	2010-05-01	Anthocyanins are phytonutrients that provide blue, purple and red colors to fruits and vegetables. The purpose of the study is to determine whether absorption of anthocyanins occurs in the acid pH of the stomach and to determine whether altering stomach pH by use of an over-the-counter medicine, Prilosec TM, alters absorption of anthocyanins from strawberries and blackberries.
OTC	NCT02844621 ↗	Effect of Proton Pump Inhibitors on Gut Microbiota and Systemic Inflammation in Older Adults	Completed	The University of Texas Health Science Center at San Antonio	Early Phase 1	2016-05-01	The purpose of this study is to evaluate the effects of a common over-the-counter medication, omeprazole, on the normal gut bacteria and inflammation in the body in healthy older adults.

All Clinical Trials for PRILOSEC

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00001191 ↗	The Use of Oral Omeprazole and Intravenous Pantoprazole in Patients With Hypersecretion of Gastric Acid	Completed	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	Phase 2	1983-02-03	Patients with Zollinger-Ellison Syndrome suffer from ulcers of the upper gastrointestinal tract, higher than normal levels of gastric acid, and tumors of the pancreas known as non-beta islet cell tumors. Patients with Zollinger-Ellison Syndrome require continuous control of their gastric acid secretion. If gastric acid levels are permitted to rise higher than normal, patients may develop severe ulcers and other complications. This study will attempt to determine the effectiveness of Omeprazole (Prilosec) in the treatment of patients with Zollinger-Ellison Syndrome. Omeprazole is a drug that functions to decrease the amount of gastric acid secreted. Patients for this study will be selected based on a previous diagnosis of Zollinger-Ellison Syndrome and/or idiopathic (unknown cause) high levels of gastric acid secretion. The patients will undergo an evaluation including history and physical examination as well as necessary laboratory tests. The proper dose of Omeprazole will then be determined in each patient . The proper dose of Omeprazole is considered the minimum amount of omeprazole required to lower gastric acid to a safe level. Every year patients participating in this study will undergo a physical examination and history. They will be questioned about symptoms associated with Zollinger-Ellison Syndrome. Gastric acid levels will be taken and evaluated and patients will undergo an upper gastrointestinal endoscopy. The effectiveness of the treatment will be measured by a clinical history to determine the control of symptoms due to high levels of gastric acid secretion.
NCT00210470 ↗	A Phase 2 Clinical Trial of the Safety and Effects of IRX-2 in Treating Patients With Operable Head and Neck Cancer	Completed	Brooklyn ImmunoTherapeutics, LLC	Phase 2	2005-07-01	This was a Phase 2a trial to investigate the safety and biological activity of the RIX-2 Regimen in patients with untreated, resectable squamous cell cancer of the head and neck (HNSCC).
NCT00210470 ↗	A Phase 2 Clinical Trial of the Safety and Effects of IRX-2 in Treating Patients With Operable Head and Neck Cancer	Completed	IRX Therapeutics	Phase 2	2005-07-01	This was a Phase 2a trial to investigate the safety and biological activity of the RIX-2 Regimen in patients with untreated, resectable squamous cell cancer of the head and neck (HNSCC).
NCT00233935 ↗	Defined Green Tea Catechin Extract in Preventing Esophageal Cancer in Patients With Barrett's Esophagus	Completed	National Cancer Institute (NCI)	Phase 1	2005-11-01	The goal of this clinical research study is to test the safety of defined green tea catechin extract at different dose levels. Researchers also want to find out what effects, good and bad, it may have on individual and their risk for esophagus cancer. Esophagus cancer is an increased risk associated with Barrett's esophagus. Chemoprevention is the use of certain drugs to keep cancer from forming, growing, or coming back. The use of defined green tea catechin extract may prevent esophageal cancer.
NCT00446004 ↗	Effect of a Proton Pump Inhibitor on Gleevec® in Healthy Volunteers	Completed	Novartis	Phase 1	2007-04-01	This is a research study that will investigate the effects of proton pump inhibitors (often used to treat stomach upset) on Gleevec® (a drug that is FDA-approved to treat some types of cancer) in healthy volunteers. Twelve healthy volunteers (six men and six women) will be recruited to complete the study. This research study will compare Gleevec® in the body when taken with and without proton pump inhibitors (PPI). Each volunteer will receive a 400 mg pill of Gleevec® on two occasions. On one occasion they will take the dose of Gleevec® alone (without PPI). On another occasion, they will take the Gleevec® after taking 40 mg of PPI daily by mouth for six days. Several blood samples will be drawn to measure the concentrations of Gleevec® and its breakdown products in the blood, with and without the influence of PPI.

Clinical Trial Conditions for PRILOSEC

Condition Name

Condition Name for PRILOSEC
Intervention	Trials
Healthy	12
Healthy Volunteers	4
Gastric Acid	2
Human Experimentation	2

Condition MeSH

Condition MeSH for PRILOSEC
Intervention	Trials
Gastroesophageal Reflux	7
Esophagitis	4
Ulcer	3
Low Back Pain	2

Clinical Trial Locations for PRILOSEC

Trials by Country

Trials by Country for PRILOSEC
Location	Trials
United States	83
Japan	36
India	7
Canada	5
Brazil	4

Trials by US State

Trials by US State for PRILOSEC
Location	Trials
Arizona	7
Pennsylvania	7
California	6
Texas	5
New York	5

Clinical Trial Progress for PRILOSEC

Clinical Trial Phase

Clinical Trial Phase for PRILOSEC
Clinical Trial Phase	Trials
Phase 4	12
Phase 3	7
Phase 2	3

Clinical Trial Status

Clinical Trial Status for PRILOSEC
Clinical Trial Phase	Trials
Completed	42
Withdrawn	3
Recruiting	2

Clinical Trial Sponsors for PRILOSEC

Sponsor Name

Sponsor Name for PRILOSEC
Sponsor	Trials
Dr. Reddy's Laboratories Limited	4
Bayer	4
Brooklyn ImmunoTherapeutics, LLC	3

Sponsor Type

Sponsor Type for PRILOSEC
Sponsor	Trials
Industry	44
Other	23
NIH	10

Clinical Trials Update, Market Analysis, and Projection for Prilosec (Omeprazole)

Last updated: October 30, 2025

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Introduction

Prilosec (omeprazole), a proton pump inhibitor (PPI), is a flagship product in the gastroesophageal reflux disease (GERD) and peptic ulcer disease segments. Since its initial approval in 1989, Prilosec has transformed acid suppression therapy, becoming a global staple. This article synthesizes recent clinical trial developments, conducts a comprehensive market analysis, and forecasts the future of Prilosec within an evolving therapeutic landscape.

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Clinical Trials Update

Recent and Ongoing Clinical Engagements

In recent years, the clinical landscape surrounding omeprazole has shifted disproportionately toward safety, generic competition, and novel therapeutic indications, driven by regulatory directives and scientific exploration:

• Gastrointestinal and Reflux Disorders: The bulk of ongoing trials focus on optimizing dosing, reducing adverse events, and exploring novel formulations. Notably, a 2021 trial (NCT04885672) examined high-dose omeprazole's efficacy in refractory GERD, revealing modest improvements but increased adverse effects alerts, suggesting cautious application in resistant cases.

• Drug-Drug Interactions & Long-term Safety: Multiple observational studies scrutinize long-term PPI use, assessing risks of CKD, fractures, and infections. For example, a 2022 cohort study (BMJ) indicated potential associations between prolonged omeprazole use and chronic kidney disease, demanding further validation.

• Novel Indications: Limited investigational studies are underway targeting Helicobacter pylori eradication adjuncts or novel prophylactic applications. The Ongoing NCT03688850 trial explores the role of omeprazole in preventing NSAID-induced gastrointestinal injury, emphasizing its utility beyond traditional indications.

Regulatory and Investigational Developments

While no recent new molecular entities or formulations derived from omeprazole have gained regulatory approval, ongoing evaluations around biosimilars and combination therapies suggest a sustained interest in expanding therapeutic options. Notably, patent expirations in key markets (e.g., US in 2009, and subsequent generic entrants) have substantially impacted market dynamics, with recent trials mainly confirming safety profiles rather than seeking new indications.

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Market Analysis

Historical Context and Market Size

Prilosec's reign epitomized dominance, with peak annual sales exceeding $6 billion globally by the late 2000s. The rise of generics since patent expiration precipitated sharp sales declines:

• Generic Competition: Over 40 generic versions now dominate the market, significantly eroding high-margin sales. As of 2023, branded Prilosec sales account for less than 10% of total omeprazole sales, primarily driven by sustained prescribing habits in branded formulations.

• Global And Regional Market Distribution: North America remains the largest market, comprising 50-60% of global sales, driven by high prevalence rates of GERD, insurance coverage, and clinical practice patterns. Europe follows, with emerging markets in Asia and Latin America witnessing increased adoption.

Drivers of Market Trends

• Shift Toward OTC Availability: OTC formulations of omeprazole have expanded access and usage, particularly for mild-to-moderate reflux symptoms, contributing to the overall volume without proportional revenue increase for original manufacturers.

• Healthcare Cost Containment: Insurers and health systems favor generic PPIs, minimizing sales of branded Prilosec, though pediatric and specific refractory cases still occasionally require prescribed formulations.

• Safety Concerns and Regulatory Scrutiny: Increasing data linking long-term PPI use with adverse outcomes provoke prescriber caution, possibly impacting consumption patterns.

Emerging Opportunities and Challenges

• Branding and Differentiation: Few companies attempt branding strategies for omeprazole; most focus on newer PPI formulations or novel drug delivery systems. However, some manufacturers explore combination therapies to address refractory GERD or Helicobacter pylori eradication, potentially revitalizing certain segments.

• Innovation Barriers: Innovations are hampered by the extensive generic presence, low profit margins, and regulatory challenges surrounding reformulation or new indications.

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Market Projection

Short-term Outlook (Next 3 Years)

• Stable Sales, Declining Revenue for Branded Formulations: Market forecasts predict a gradual decline in branded Prilosec sales, aligning with generic prevalence. Growth opportunities are limited, mainly driven by chronic GERD management in specific patient groups.

• Generic Market Saturation: The proliferation of generic omeprazole further constricts pricing power and margins for branded versions, with some bioequivalent generics priced below branded prescriptions in developed markets.

• Increased Focus on Safety: Heightened awareness of long-term adverse effects may influence prescribing habits, leading to decreased initiation of PPI therapies unless clinically necessary — potentially reducing overall market volume.

Long-term Outlook (Beyond 5 Years)

• Market Consolidation & Innovation: With patent cliffs largely played out, the market will continue to consolidate around a handful of manufacturers who develop value-added formulations or combination therapies. Research into novel delivery methods (e.g., sustained-release formulations) may carve niche markets.

• Shift Toward Alternative Therapies: Emerging therapies, including potassium-competitive acid blockers (P-CABs like vonoprazan), threaten to displace PPIs as the first-line agents for acid suppression. The adoption rate of P-CABs could directly influence continued demand for omeprazole.

• Regulatory and Safety-Driven Dynamics: Ongoing safety concerns may prompt regulatory restrictions or guidelines limiting long-term use, especially in vulnerable populations, further constricting the market.

Global Market Forecast

• Compound Annual Growth Rate (CAGR): The global omeprazole market is expected to decline at a 2-3% CAGR over the next five years, primarily driven by generic erosion and changing clinical guidelines.

• Regional Variances: Developing markets may see modest growth fueled by increased healthcare access, whereas mature markets will experience stabilization or decline.

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Strategic Implications

For pharmaceutical companies and investors, Prilosec’s market trajectory underscores a near-term diminishment in branded sales but signals opportunities in niche applications, combination therapies, and alternative delivery mechanisms. Companies should monitor clinical trial outcomes, regulatory developments, and the evolving landscape of acid suppression therapy to adapt their strategies effectively.

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Key Takeaways

• Clinical research on omeprazole primarily emphasizes safety, long-term effects, and new formulations, with no recent approvals of new indications.

• The global Prilosec market has declined significantly due to patent expirations and the proliferation of generics, with a stable but shrinking branded segment.

• Emerging therapies, such as P-CABs, threaten to displace traditional PPIs, including omeprazole, especially in refractory cases.

• Regulatory scrutiny and safety concerns may influence prescribing patterns, possibly reducing long-term use in vulnerable populations.

• Future growth hinges on innovation within existing PPI formulations, strategic positioning in niche markets, and adaptation to evolving clinical guidelines.

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FAQs

1. What are the latest clinical developments related to Prilosec?
Recent trials focus on optimizing dosing in refractory GERD and assessing long-term safety implications. No new indications or formulation approvals have emerged, emphasizing safety and long-term effects.

2. How has market competition impacted Prilosec’s sales?
Patent expirations led to widespread generic availability, collapsing branded sales. OTC availability further diminishes prescription revenues, concentrating the market in generics.

3. Are there safety concerns affecting Prilosec’s market?
Yes, studies link prolonged PPI use with risks like chronic kidney disease, fractures, and infections. These findings influence prescribing practices and regulatory policies.

4. What emerging therapies could affect Prilosec’s market?
Potassium-competitive acid blockers (P-CABs) like vonoprazan offer faster, more sustained acid suppression, vying for market share against traditional PPIs.

5. What strategic options are available for pharmaceutical companies regarding Prilosec?
Focusing on niche indications, developing combination therapies, improving drug delivery, or exploring safety profiles can help maintain relevance amidst generic competition.

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References

[1] ClinicalTrials.gov. Omeprazole-related trials.

[2] BMJ Study on Long-Term PPI Safety.

[3] Market research reports on global PPI market trends.

[4] FDA and EMA regulatory guidelines on PPIs.