CLINICAL TRIALS PROFILE FOR PRILOSEC OTC

505(b)(2) Clinical Trials for PRILOSEC OTC

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 OTC

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.
NCT00446004 ↗	Effect of a Proton Pump Inhibitor on Gleevec® in Healthy Volunteers	Completed	University of Pittsburgh	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 OTC

Condition Name

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

Condition MeSH

Condition MeSH for PRILOSEC OTC
Intervention	Trials
Gastroesophageal Reflux	7
Esophagitis	4
Ulcer	3
Malnutrition	2

Clinical Trial Locations for PRILOSEC OTC

Trials by Country

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

Trials by US State

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

Clinical Trial Progress for PRILOSEC OTC

Clinical Trial Phase

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

Clinical Trial Status

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Withdrawn	3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

Clinical Trial Sponsors for PRILOSEC OTC

Sponsor Name

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

Sponsor Type

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

Last updated: July 28, 2026

Prilosec OTC clinical trials update, market analysis, and revenue projection (2026–2035)

Prilosec OTC (omeprazole magnesium delayed-release capsules) is an FDA OTC proton-pump inhibitor (PPI) indicated for short-term treatment of frequent heartburn. The product is off-patent from an active-ingredient standpoint; competition is dominated by generics and branded competitors in OTC acid suppression. The clinical-trials runway is limited for new entrants, with most current activity centered on new dose forms, reformulations, line extensions, and comparative effectiveness studies rather than new mechanism claims.

From a market perspective, the OTC heartburn category is stable with mid-single-digit inflation in value driven by channel mix, pack sizes, and pharmacy/club pricing. Unit growth is constrained by long-term PPI penetration and substitution to generics; value growth is more resilient. Revenue projection for Prilosec OTC aligns with share maintenance rather than share capture, with downside risk from price compression and brand-to-generic switching.

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What clinical trials exist for Prilosec OTC (omeprazole magnesium) and what is updated in 2024–2026?

Core mechanism is mature. Omeprazole is an established PPI with extensive pre-2000 clinical data. For Prilosec OTC specifically, the most visible “clinical trial” activity in recent years is typically one of the following:

• OTC switching/label-support studies evaluating heartburn relief onset, duration, and symptom burden using OTC-style end points.
• Comparative bioavailability / bioequivalence studies versus other omeprazole formulations (often required for formulation changes rather than for regulatory re-approval).
• Real-world evidence (RWE) studies using claims, patient-reported outcomes, or electronic health record proxies for GERD/heartburn outcomes.
• Stability, formulation, and shelf-life work for packaging and formulation tweaks.

Featured snippet answer: Current Prilosec OTC “clinical trial updates” largely reflect label-support, comparative performance, and formulation/bioavailability programs rather than new indication-defining Phase 2/3 trials.

Where do trial updates typically show up

• ClinicalTrials.gov for formulation/bioavailability/BE or OTC-related studies using omeoprazole.
• Peer-reviewed comparative studies assessing time-to-relief and patient-reported symptom improvement across OTC PPIs.
• Postmarketing observational studies tracking adherence and persistence in self-selected OTC users.

Implication for investors and licensors

Because the active ingredient is long established, the probability-weighted value of new clinical programs is lower than for novel mechanism drugs. Most IP value is in formulations, dosing regimens, packaging, and potential line extensions, not new systemic claims.

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How big is the OTC heartburn market and what share does Prilosec OTC realistically hold?

Category framing: Prilosec OTC competes in the OTC acid suppression segment led by PPIs (omeprazole) and H2 blockers (famotidine), with occasional adjacency from antacids.

Market sizing logic (value driver model)

• Units: driven by incidence of frequent heartburn, demographic mix, and recurrence behavior.
• Price: driven by competition from generics, promotion intensity, pack size mix (e.g., 42 vs 14 day supplies), and channel-specific pricing (drugstore vs club vs e-commerce).
• Brand-to-generic substitution: major determinant of long-run revenue.

Featured snippet answer: The OTC heartburn category grows modestly in units and mid-single-digits in value, with branded PPI revenue tied to share maintenance and pricing rather than category expansion.

Share constraints

Prilosec OTC’s share is pressured by:

• Generic omeprazole availability in identical OTC dosing.
• Substitution among OTC PPIs and switching due to pharmacy shelf dynamics.
• Private label and store-brand acid suppression.

Business takeaway

Unless Prilosec OTC changes the competitive bargain through pricing, bundling, or differentiated formulation, long-run revenue projections should assume limited share growth and price/pack-driven value changes.

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What is the revenue projection for Prilosec OTC from 2026 to 2035?

Projection approach (category-consistent, share-maintenance baseline)

• Assume Prilosec OTC tracks the OTC heartburn category in value with a slight underperformance or parity depending on promotion cycles and price compression.
• Model revenue as:
  Revenue = Category value × Expected brand OTC share × Net pricing factor
  where the net pricing factor declines slowly as competition intensifies.

Base-case projection (directional)

• 2026–2028: modest value growth, driven by pack mix and inflation, offset by ongoing generic pressure.
• 2029–2032: near-flat to low-single-digit decline in net sales as competitive intensity increases.
• 2033–2035: stable low growth or mild decline, dominated by promotional resets and incremental channel recovery.

Featured snippet answer: Over 2026–2035, Prilosec OTC revenue is likely to show low-single-digit growth early, then transition to flat-to-declining outcomes under continued price pressure from generic omeprazole.

Scenario table (directional range, not point estimates)

Year band	Base case	Downside case	Upside case	Primary drivers
2026–2028	+0% to +4% CAGR	-2% to 0% CAGR	+3% to +6% CAGR	Promotion mix, pricing, pack mix
2029–2032	-1% to +2% CAGR	-3% to -1% CAGR	+1% to +4% CAGR	Generic price compression, channel shifts
2033–2035	-1% to +1% CAGR	-2% to 0% CAGR	+1% to +3% CAGR	OTC penetration maturity, substitution dynamics

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Which patents protect Prilosec OTC (omeprazole magnesium) and when do they expire?

Active ingredient protection has expired in most relevant jurisdictions for the parent molecule. For OTC products, remaining protectable IP typically sits in:

• Formulation-specific patents (release profile, salts, enteric coatings, excipient systems)
• Manufacturing methods (process controls, impurity profiles)
• Combination or packaging claims (less common in OTC PPIs)
• Trademarks and brand trade dress (non-expiring but not a barrier to generics)

Featured snippet answer: Prilosec OTC is generally constrained by expired omeprazole active-ingredient patents; any remaining IP is typically formulation/process-level, with limited practical impact on generic entry.

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What generic entry risks exist for Prilosec OTC?

Generic risk is structural and ongoing, not a discrete event:

• Multiple ANDA equivalents for OTC omeprazole exist or can be supported through existing regulatory pathways.
• Competitive response mainly comes through pricing and promotion, not new scientific barriers.

Featured snippet answer: The dominant generic risk for Prilosec OTC is continual price compression from generic omeprazole products and private label substitutes.

Key entry levers for competitors

• Competitive pricing through scale manufacturing.
• Shelf placement via pharmacy category management.
• Promotional spend timed to peak heartburn seasons and consumer shopping calendars.
• Pack size offerings and couponing.

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What is the Orange Book status of Prilosec OTC?

Prilosec OTC is an OTC omeprazole magnesium delayed-release capsule product. Orange Book listings typically reflect:

• Existing approved NDA/ANDA entries
• Patent numbers and expiration dates (where listed)
• Methods and formulations covered by listed patents

Featured snippet answer: Orange Book status is generally not a meaningful barrier for new OTC generic equivalents because omeprazole’s foundational patents are expired; listed patents, if any, are usually limited to specific formulations or processes.

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How does Prilosec OTC compare with other OTC PPIs and famotidine (H2 blockers)?

Competitive set

• OTC omeprazole brands vs generic omeprazole
• Other OTC PPIs (depending on local availability)
• H2 blockers (famotidine) and antacids

Observed market behavior

• PPIs typically outperform H2 blockers for frequent heartburn symptom control, but consumer switching depends on price.
• When generics are priced below branded PPIs, branded share declines unless brand pricing is supported by promotions.

Featured snippet answer: Prilosec OTC competes primarily on price and pack value versus generic omeprazole and on clinical preference versus H2 blockers, with generic substitution dominating mid-to-long-term share.

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What formulation patents protect Prilosec OTC and do they affect generic substitution?

For OTC PPIs, formulation patents can matter if they cover:

• Enteric coating technologies impacting release profile
• Stability and shelf-life improvements that enable certain pack configurations
• Particle size control and impurity profile targets

Featured snippet answer: Even when formulation/process patents exist, their practical impact on generic substitution is limited because the active ingredient and core dose form are well established and substitutes can typically be made under existing regulatory requirements.

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What patent litigation affects Prilosec OTC?

For off-patent OTC PPIs, litigation exposure is usually lower than for novel therapeutics. When present, it typically involves:

• Narrow formulation/process disputes
• Trademark and trade dress disputes
• Generic patent challenges in earlier eras

Featured snippet answer: Patent litigation is not a primary near-term driver for Prilosec OTC market outcomes; competition is driven by generic availability and pricing.

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What FDA regulatory pathways apply to generic Prilosec OTC and what does that mean for timelines?

Regulatory route

• Generic omeprazole OTC products typically use ANDA pathways (with labeling and equivalence testing).
• BE studies and OTC labeling compliance are key timing determinants.

Featured snippet answer: Regulatory timelines for generic entry are typically governed by ANDA readiness and required equivalence work, not by long clinical trials, because the mechanism is established.

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Commercial outlook: what revenue exposures matter most (price, volume, promotion, channel)?

Primary sensitivities

1. Net price: branded promotional discounting vs generic benchmark pricing.
2. Pack mix: value per unit often shifts with 14-day vs 42-day pack strategies.
3. Channel mix: drugstores vs club vs online affects realized pricing and promotional intensity.
4. Share of shelf: planogram changes and retailer negotiations.

Featured snippet answer: Prilosec OTC revenue is most sensitive to net pricing and pack mix, with volume constrained by category maturity.

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Key Takeaways

• Prilosec OTC clinical activity is limited in scope and typically centers on label-support, bioequivalence, and formulation/package improvements rather than new Phase 2/3 programs.
• OTC heartburn market growth is modest; unit growth is constrained by high PPI penetration and switching to generics.
• 2026–2035 revenue is best modeled as share-maintenance with low-single-digit value growth early, transitioning to flat-to-declining results under continued generic price compression.
• The dominant generic entry risk is ongoing pricing pressure rather than discrete patent expiry events.
• Regulatory entry for generic omeprazole is generally feasible through established ANDA/Bioequivalence requirements.

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FAQs

1) Are there new clinical trials showing improved outcomes for OTC omeprazole in 2024–2026?

Recent activity is typically comparative effectiveness, OTC label-support, and bioequivalence related rather than new indication-defining trials.

2) Will a new PPI formulation (e.g., faster release) create a defensible advantage for Prilosec OTC?

Defensibility is usually limited unless the formulation produces measurable, regulator-recognized differentiation that can be supported by narrow IP and a sustained pricing premium.

3) What drives Prilosec OTC seasonal sales most?

Heartburn-related demand peaks align with seasonal retail shopping and dietary patterns, with promotion intensity and pack availability as key multipliers.

4) How quickly can generic omeprazole OTC products enter once approved?

Once approvals and retail supply readiness are in place, penetration can be rapid through shelf placement and promotion, with pricing adjustment occurring immediately.

5) What is the main threat to branded Prilosec OTC long term?

Generic omeprazole and private label substitution driven by price gaps, not mechanism-based therapeutic failure.

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References

1. FDA. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. U.S. Food and Drug Administration.
2. FDA. Approved Drug Products and Therapeutic Equivalence Evaluations (ANDA/Labeling guidance materials). U.S. Food and Drug Administration.
3. ClinicalTrials.gov. Omeprazole (and related OTC formulations) studies. National Library of Medicine.