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.

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).

Clinical Trial Conditions for PRILOSEC

Condition Name

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

Condition MeSH

Condition MeSH for PRILOSEC
Intervention	Trials
Gastroesophageal Reflux	7
Esophagitis	4
Ulcer	3

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
AstraZeneca	3

Sponsor Type

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

PRILOSEC (omeprazole): Clinical-trials update, market analysis, and projections

Last updated: May 2, 2026

What is PRILOSEC (omeprazole) and what clinical-trials activity remains?

PRILOSEC is a brand of omeprazole, a proton pump inhibitor (PPI) used for acid-related disorders (including GERD and peptic ulcer disease). The active ingredient is widely available as generics across major markets, which limits new late-stage pivotal development and shifts the role of remaining studies toward post-authorization use, formulation, comparative effectiveness, dosing optimization, and real-world evidence.

Clinical-trials update (current-state readout)

Across major clinical-trial registries, ongoing activity for omeprazole is typically small-scale, comparative, or real-world focused, rather than new mechanism-defining Phase 3 programs that would expand indications or reset market exclusivity. In practical terms, PRILOSEC is not tracked as a distinct clinical-development asset; it is tracked as an originator brand of an off-patent molecule.

Implication for investors and R&D planners: the development pipeline for PRILOSEC is not positioned to create new regulatory exclusivity. Market growth is therefore driven by prevalence, guideline adherence, channel share, and price erosion mitigation rather than new clinical evidence driving label expansion.

How big is the global market for PPIs, and where does PRILOSEC fit?

PRILOSEC competes in the broader PPI class rather than as a single-molecule standalone market. Since omeprazole is widely generic, the commercial outcome depends on:

• Local brand strategy in markets that still support brand premiums
• Channel strength (retail, pharmacy chains, wholesaler contracting)
• Payer and formulary dynamics
• Conversion pressure from newer agents (notably esomeprazole and other PPIs) and from non-PPI alternatives when present in guidelines

Market structure (how pricing works)

PPIs show a pattern typical of mature generics:

• Originator brands trade mainly on brand trust, fixed formularies, and physician habits
• Generic penetration compresses net price and shifts competition to cost and rebates
• Therapy volume (patients treated) supports revenue even as unit economics decline

What does the competitive landscape look like for omeprazole/PRILOSEC?

The competitive set is dominated by:

• Generic omeprazole (multiple manufacturers, high substitutability)
• Other PPIs (especially esomeprazole and lansoprazole) depending on region and formulary
• Emerging reflux-management trends that can affect long-term PPI duration and dosing intensity, such as step-down therapy and “lowest effective dose” strategies

Brand premium constraints

For PRILOSEC, brand premium is constrained by:

• Automatic substitution and pharmacy-level switching to cheaper generics
• Tender and contract pricing at wholesaler and pharmacy group levels
• Payer preference for lowest-cost PPIs, with limited exceptions for branded originators

What do market projections look like for PRILOSEC-like exposure?

Because omeprazole is off-patent, projections are not about revenue growth from exclusivity. They are about:

• Maintenance of volume share in ongoing-treated populations
• Timing and intensity of price compression
• Migration dynamics within PPIs (omeprazole vs esomeprazole vs others)
• Regulatory and reimbursement tightening around long-term use

Baseline expectation for 5-year outlook

A practical projection framework for a mature, generic-exposed PPI brand:

• Unit growth: modest, aligned to GERD prevalence trends and prescribing behavior
• Value growth: limited by ongoing generic price declines
• Net revenue: depends on how effectively PRILOSEC protects distribution and formulary positioning

Directional result: PRILOSEC-like revenue typically trends sideways to slightly down in value terms in mature markets, with potential stabilization where brand rebates and channel contracts offset further price erosion.

How do reimbursement and guideline trends affect demand?

Demand for PPIs is shaped by prescribing duration and step-down practices. Key themes that typically reduce long-term usage intensity:

• “Lowest effective dose” recommendations
• Periodic reassessment for chronic users
• Earlier use of step-down approaches after symptom control
• Increased emphasis on diagnostic confirmation for alarm symptoms (which can alter empiric prescribing patterns)

These forces can slow incremental patient-days even while maintaining overall treated prevalence.

What are the main commercial levers for a PRILOSEC brand strategy?

Given generic substitution pressure, brand strategy focuses on:

• Formulation differentiation (where available) and consistent patient experience
• Contracting: securing pharmacy and payer agreements that keep the brand on-preferred lists
• Targeted patient segments: patients with prior successful response, continuity of care, and clinician familiarity
• Service-level economics: rebates that make the brand competitive versus lowest-cost generics

What is the clinical development “signal” investors should use for PRILOSEC?

For off-patent PPIs, the “signal” is not new efficacy breakthroughs. It is:

• Comparative effectiveness evidence that supports payer decisions
• Safety and tolerability studies that align with guideline messaging
• Formulation work that improves adherence, reduces dosing frequency, or supports switchback strategies
• Pharmacokinetic and bioequivalence work that maintains approvals across formulations and geographies

How to interpret remaining trials: safety and comparative outcomes

Most remaining clinical activity for omeprazole tends to focus on routine questions:

• Real-world symptom control and adherence
• Switching strategies between PPIs
• Safety signals monitoring in large patient cohorts
• Comparative trials among PPIs or across dosing regimens

These studies can support marketing and formulary negotiations, but they generally do not reset exclusivity.

---

Key Takeaways

• PRILOSEC is a brand of omeprazole, a mature PPI where new late-stage pivotal development is limited and market performance is primarily determined by generic substitution, pricing, and channel/payer contracting.
• Clinical-trials activity for omeprazole typically supports post-authorization use, comparative effectiveness, and operational improvements rather than new exclusivity-generating indications.
• Market projections for PRILOSEC-like exposure are mostly value-limited by price erosion, with volume stability possible where brand strategy offsets substitution pressures.
• Guideline-driven step-down approaches and “lowest effective dose” practices can cap incremental patient-days, shifting growth toward well-maintained treated populations and payer-managed utilization.

---

FAQs

1) Is PRILOSEC currently protected by patent exclusivity in major markets?

No. Omeprazole’s originator-level patent exclusivity has long expired, and the market is dominated by generics in major jurisdictions.

2) What kind of clinical trials still occur for omeprazole?

Most trials are post-authorization and focus on comparative effectiveness, real-world use, dosing regimens, adherence, and routine safety monitoring, rather than new mechanism or Phase 3 pivotal programs.

3) What drives PRILOSEC revenue in an off-patent environment?

Distribution and formulary access, rebate structure, brand conversion retention, and contract pricing determine whether PRILOSEC holds share versus lower-cost generics.

4) Does guideline step-down therapy reduce PPI market demand?

It can reduce long-term patient-days per patient, which limits value growth. However, underlying GERD prevalence still supports treated volume.

5) Which competitors matter most for PRILOSEC?

The primary pressure comes from generic omeprazole. Competitive alternatives include other PPIs depending on regional formulary and pricing dynamics.

---

References

[1] ClinicalTrials.gov. Omeprazole (search results and registry listings). U.S. National Library of Medicine. https://clinicaltrials.gov/
[2] FDA. Prilosec (omeprazole) Prescribing Information. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/
[3] EMA. Omeprazole-related product information and regulatory documents for PPIs (various). European Medicines Agency. https://www.ema.europa.eu/
[4] IMS Health / IQVIA. PPI market reporting and pricing dynamics (industry datasets, general market structure). IQVIA. https://www.iqvia.com/