CLINICAL TRIALS PROFILE FOR DORZOLAMIDE HYDROCHLORIDE; TIMOLOL MALEATE

All Clinical Trials for dorzolamide hydrochloride; timolol maleate

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00108017 ↗	Comparison of the Effects of Two Glaucoma Drugs Over 24 Hours (0507A-137)(COMPLETED)	Completed	Merck Sharp & Dohme Corp.	Phase 3	2005-04-01	This study is comparing 2 medications for glaucoma and how effective they are at controlling glaucoma over the course of an entire day.
NCT00273442 ↗	Assessing Cosopt Switch Patients	Completed	Pharmaceutical Research Network	Phase 4	2005-11-01	To assess the safety and efficacy of a cohort of patients switched to the dorzolamide/timolol maleate fixed combination because they are insufficiently controlled on latanoprost monotherapy.
NCT00440336 ↗	Comparison of Efficacy of Two Groups of Glaucoma Drops (Xalatan vs.Cosopt) in Reducing Eye Pressure Following Laser (SLT)Treatment in the Management of Glaucoma.	Unknown status	Merck Sharp & Dohme Corp.	N/A	2006-10-01	WHAT IS THIS STUDY ABOUT? Glaucoma and ocular hypertension are chronic eye diseases that can damage the optic nerve and lead to vision loss or blindness. The optic nerve acts like an electric cable with over a million wires. This nerve is responsible for carrying images from the eye to the brain. The way glaucoma and ocular hypertension cause blindness depends on many factors, but the most important factor is the increased pressure inside the eye (intraocular pressure). There is no cure for glaucoma or ocular hypertension. However, lowering the pressure inside the eye has been shown to slow the progression of disease. Intraocular pressure can be lowered by glaucoma medication, laser treatment, or surgery. You have open angle glaucoma, pseudoexfoliative glaucoma, or ocular hypertension. Researchers want to find out more about how 2 drugs called Cosopt (dorzolamide hydrochloride and timolol maleate) and Xalatan (latanoprost) can help people with these conditions. Cosopt and Xalatan are both eye drops that are approved by the U.S. Food and Drug Administration (FDA) to reduce intraocular pressure in people with open angle glaucoma and ocular hypertension. The study doctor will do a laser procedure called Selective Laser Trabeculoplasty (SLT) on people in this study to help lower their intraocular pressure. The FDA has approved SLT to treat open angle glaucoma and ocular hypertension. Then the study doctor will ask some participants to use either Cosopt or Xalatan, if their intraocular pressure is still too high 4 to 6 weeks after the SLT procedure. The study doctor wants to see which of the 2 study drugs (Cosopt or Xalatan) is better at reducing intraocular pressure after SLT. It is planned that about 30 people with glaucoma or ocular hypertension who are at least 18 years old will be in this study. Out of the participants whose intraocular pressure is still too high after SLT, half will use Cosopt and half will use Xalatan. You do not have to be in this study to have SLT or to use Cosopt or Xalatan.
NCT00440336 ↗	Comparison of Efficacy of Two Groups of Glaucoma Drops (Xalatan vs.Cosopt) in Reducing Eye Pressure Following Laser (SLT)Treatment in the Management of Glaucoma.	Unknown status	Advanced Glaucoma Specialists	N/A	2006-10-01	WHAT IS THIS STUDY ABOUT? Glaucoma and ocular hypertension are chronic eye diseases that can damage the optic nerve and lead to vision loss or blindness. The optic nerve acts like an electric cable with over a million wires. This nerve is responsible for carrying images from the eye to the brain. The way glaucoma and ocular hypertension cause blindness depends on many factors, but the most important factor is the increased pressure inside the eye (intraocular pressure). There is no cure for glaucoma or ocular hypertension. However, lowering the pressure inside the eye has been shown to slow the progression of disease. Intraocular pressure can be lowered by glaucoma medication, laser treatment, or surgery. You have open angle glaucoma, pseudoexfoliative glaucoma, or ocular hypertension. Researchers want to find out more about how 2 drugs called Cosopt (dorzolamide hydrochloride and timolol maleate) and Xalatan (latanoprost) can help people with these conditions. Cosopt and Xalatan are both eye drops that are approved by the U.S. Food and Drug Administration (FDA) to reduce intraocular pressure in people with open angle glaucoma and ocular hypertension. The study doctor will do a laser procedure called Selective Laser Trabeculoplasty (SLT) on people in this study to help lower their intraocular pressure. The FDA has approved SLT to treat open angle glaucoma and ocular hypertension. Then the study doctor will ask some participants to use either Cosopt or Xalatan, if their intraocular pressure is still too high 4 to 6 weeks after the SLT procedure. The study doctor wants to see which of the 2 study drugs (Cosopt or Xalatan) is better at reducing intraocular pressure after SLT. It is planned that about 30 people with glaucoma or ocular hypertension who are at least 18 years old will be in this study. Out of the participants whose intraocular pressure is still too high after SLT, half will use Cosopt and half will use Xalatan. You do not have to be in this study to have SLT or to use Cosopt or Xalatan.
NCT00471068 ↗	Study of Travatan and Cosopt in Primary Open-Angle Glaucoma or Ocular Hypertension	Terminated	Alcon Research	Phase 4	2007-03-01	To compare the efficacy and safety in patients treated with travoprost versus dorzolamide/timolol maleate combination in patients with open-angle glaucoma or ocular hypertension
NCT00811850 ↗	Comparing Effects of Two Fixed Combinations Ophthalmic Solutions on Ocular Blood Flow	Completed	Allergan	Phase 4	2008-12-01	A 10 week evaluation, crossover design study including a 3 week washout period between treatments, to determine the effects of Combigan® (fixed combination brimonidine tartrate 0.2%/timolol maleate 0.5%) and Cosopt® (fixed combination dorzolamide hydrochloride-timolol maleate ophthalmic solutions) on ocular blood flow as measured by retrobulbar blood flow.
NCT00815373 ↗	The Effects of Cosopt® Vs Xalacom® on Ocular Hemodynamics and Intraocular Pressure (IOP) in Primary Open-angle Glaucoma (POAG)	Withdrawn	Meir Medical Center	N/A	2008-12-01	Both Cosopt® and Xalatan® plus Timoptic® will significantly lower IOP, however only Cosopt® will demonstrate positive hemodynamic effects. The clinical significance of this will be investigated by examining the ophthalmic and short posterior ciliary arteries to determine the blood supply to the optic nerve head, the site of damage in glaucoma

Clinical Trial Conditions for dorzolamide hydrochloride; timolol maleate

Condition Name

Condition Name for dorzolamide hydrochloride; timolol maleate
Intervention	Trials
Glaucoma	5
Ocular Hypertension	5
Open-Angle Glaucoma	3
Exfoliation Syndrome	1

Condition MeSH

Condition MeSH for dorzolamide hydrochloride; timolol maleate
Intervention	Trials
Glaucoma	8
Ocular Hypertension	6
Hypertension	4
Glaucoma, Open-Angle	4

Clinical Trial Locations for dorzolamide hydrochloride; timolol maleate

Trials by Country

Trials by Country for dorzolamide hydrochloride; timolol maleate
Location	Trials
United States	8
Brazil	1
Israel	1
Portugal	1

Trials by US State

Trials by US State for dorzolamide hydrochloride; timolol maleate
Location	Trials
Florida	1
Indiana	1
Massachusetts	1
South Carolina	1
Oklahoma	1

Clinical Trial Progress for dorzolamide hydrochloride; timolol maleate

Clinical Trial Phase

Clinical Trial Phase for dorzolamide hydrochloride; timolol maleate
Clinical Trial Phase	Trials
Phase 4	4
Phase 3	2
Phase 1	1

Clinical Trial Status

Clinical Trial Status for dorzolamide hydrochloride; timolol maleate
Clinical Trial Phase	Trials
Completed	4
Withdrawn	2
Terminated	1

Clinical Trial Sponsors for dorzolamide hydrochloride; timolol maleate

Sponsor Name

Sponsor Name for dorzolamide hydrochloride; timolol maleate
Sponsor	Trials
Merck Sharp & Dohme Corp.	2
Allergan	2
Pharmaceutical Research Network	1

Sponsor Type

Sponsor Type for dorzolamide hydrochloride; timolol maleate
Sponsor	Trials
Industry	5
Other	5

Dorzolamide Hydrochloride + Timolol Maleate Clinical Trials Update, Market Analysis, and Future Revenue Projection

Last updated: July 27, 2026

What is the current clinical development pipeline for dorzolamide hydrochloride and timolol maleate?

No new late-stage registrational clinical trials are readily identifiable as active or completed for the combination dorzolamide HCl plus timolol maleate. The product is long established as an ophthalmic combination for lowering intraocular pressure in glaucoma and ocular hypertension, with the clinical literature dominated by older efficacy and safety studies and routine post-approval use rather than new phase programs that generate a modern, trackable “pipeline” signal.

Are there any phase 3 or phase 4 trials that changed the regulatory posture?

No. The combination does not show a contemporaneous, clearly documented phase 3/4 program that would materially shift labeling, dosing frequency, delivery system class, or interchangeability status in a way that is traceable at the trial-registry level.

What trial types do still show up for this class?

When activity does appear for established ophthalmic combinations like this, it is usually limited to:

• Formulation or bioequivalence studies for generic/“authorized generic” products
• Device or patient-use studies (drop instillation training, adherence)
• Pharmacokinetic comparisons
• Safety surveillance and real-world evidence studies, often non-interventional

What is the current regulatory status and exclusivity position for dorzolamide/timolol?

The combination is not tied to ongoing brand-style market exclusivity that typically blocks generics in the way newer biologics and single-brand small molecules do. In ophthalmology, once a combination is established, market access is usually governed by:

• Patent estates listed in the Orange Book (for NDA products)
• Implicit exclusivity windows around initial approvals, reformulations, or new dosage forms (if any)
• Litigation outcomes affecting entry dates for specific labeled strengths/dosage forms
• Generic or “authorized generic” launches under ANDA pathways

What patents protect dorzolamide hydrochloride + timolol maleate, and when do they expire?

Patent protection remains the key driver of near-term availability and pricing, but the combination itself is mature and the dominant market reality is generic competition. For this topic, patent strength and expiration depend on the specific NDA holder and labeled product (strength, dosage form, and manufacturer listing) and the specific patent family (active ingredient composition, formulation, method of treatment, or packaging).

A complete, accurate “patent-by-patent” expiration map cannot be produced here because the controlling Orange Book listings and associated patent numbers for the currently marketed NDA(s) are not provided in the prompt. Without those listings, a reliable expiration timeline would be speculative.

Which companies currently sell dorzolamide HCl/timolol maleate, and how competitive is pricing?

Competition is structurally high. Dorzolamide HCl/timolol maleate is a standard-of-care dual mechanism intraocular pressure (IOP) lowering option, and the market typically includes:

• Multiple generic manufacturers
• Price competition at the wholesaler and pharmacy level
• Substitution driven by payer formularies and automatic generic dispensing rules

In practical commercialization terms, revenue is generally driven by:

• Volume retention in glaucoma therapy lines
• Payer tiering outcomes
• Stability of generic acquisition cost
• Contracting dynamics with large wholesalers and PBMs

What is the market size for dorzolamide hydrochloride + timolol maleate?

A precise current-year market size requires validated commercial datasets (IQVIA, Clarivate/DRG, GlobalData, SSR Health, or similar). No such dataset or country scope was provided, so any number would risk being inaccurate.

What can be stated with business relevance:

• The combination sits in a mature ophthalmic segment with steady but non-growth-oriented unit demand
• Incremental growth tends to come from population aging and glaucoma prevalence trends
• Competitive pricing compresses per-unit revenue
• Where generics dominate, market value growth often lags volume growth

What drives demand: glaucoma prevalence, prescribing behavior, and therapy switching?

Demand is stable and primarily driven by:

• Glaucoma incidence and prevalence growth (aging demographics)
• Persistence to therapy lines (switching to other agents if tolerability issues arise)
• Clinician preference for fixed combinations versus switching between monotherapies
• Insurance formulary placement and prior authorization behavior

Because the product is established, incremental demand typically does not come from new clinical breakthrough evidence. It comes from steady disease burden and prescribing inertia in chronic ophthalmic care.

How does dorzolamide/timolol compare with competing fixed combinations in glaucoma?

Fixed-combination alternatives in topical glaucoma include prostaglandin-based combinations (where applicable), and other dual-mechanism regimens that compete on:

• IOP lowering efficacy profile (often class-dependent)
• Dosing convenience (once daily vs twice daily)
• Side effect patterns (ocular irritation, stinging, hyperemia, etc.)
• Formulary access and copay tiers

For this specific combination, competitive differentiation is generally not “new clinical performance.” It is mostly managed through payer access, generic availability, and patient tolerability.

When do generics face entry risk for dorzolamide/timolol products?

Entry risk depends on whether any Orange Book patents are asserted against a specific ANDA and whether Paragraph IV challenges have succeeded or settled. Without the underlying Orange Book patent list and any associated litigation docket data for the specific NDA(s), a correct entry calendar cannot be built.

Business reality for mature combinations: generic entry risk is usually limited to discrete, product-specific patent families and settlement terms, not to the entire class.

What patent litigation affects dorzolamide hydrochloride + timolol maleate?

Patent litigation is product-and-NDA-specific. For older ophthalmic combination products, litigation often concentrates on:

• Composition of matter or formulation patents
• Method-of-treatment patents (less common for fixed combinations now)
• Generic design-around strategies and labeling carve-outs
• Settlement agreements that specify “at-risk” dates and sometimes geographic carve-outs

A litigation and settlement timeline cannot be produced accurately without the relevant court dockets and asserted patents for the currently marketed NDA(s).

What is the biosimilar risk for dorzolamide/timolol?

None. This is a small-molecule ophthalmic combination, not a biologic. Biosimilar frameworks do not apply.

What generic entry risks exist for dorzolamide/timolol by strength and dosage form?

Risk is concentrated in:

• Patent coverage for the exact labeled strength and formulation
• Manufacturing method claims (if present)
• Any packaging device patents tied to the approved label presentation

To produce a per-strength entry risk map, the NDA-specific Orange Book patent list is required. It is not present in the prompt, so the analysis cannot be completed.

What is the forecast for revenue and volume: base case, bull case, bear case?

A numeric revenue projection requires current-year market value, unit volume, pricing trends, and expected timing of any generic entry/price resets. Those inputs were not provided.

What the projection can do without those inputs is define the forecasting mechanics that matter for this product:

• Base case: steady unit volume tied to glaucoma prevalence, modest net price erosion from continued generic competition
• Bull case: improved formulary placement, reduced supply disruptions, and fewer price cuts via contracting
• Bear case: accelerated price erosion from additional entrants, larger formulary switches to alternative classes, or supply instability

How to model the economics (the KPIs that will move the forecast)

For a mature ophthalmic generic-dominated combination, revenue moves with:

• Net price (after rebates/contracts)
• Pharmacy/WAC-to-NADR spread dynamics (jurisdiction-specific)
• Dispensing growth or contraction (TRx or patient counts)
• Share shift versus competing IOP-lowering regimens
• Margin volatility driven by wholesale contract renegotiations

What outcomes would change the forecast materially?

Forecast shifts would typically require one of:

• A new brand-like product reformulation with distinct exclusivity (new device, new dose form, or new combination)
• A major regulatory labeling update that changes standard-of-care positioning
• A successful new patent enforcement or settlement that delays additional generic entry
• A step-change in pricing caused by a supply event (shortages) rather than demand

No such material change is identifiable from the prompt alone at a trial and regulatory level.

Key Takeaways

• Dorzolamide HCl/timolol maleate is a mature fixed ophthalmic combination with stable chronic demand driven by glaucoma prevalence.
• No clearly traceable late-stage clinical trial program is identifiable as active or likely to drive a major label change.
• Market dynamics are dominated by generic competition and contracting-driven pricing, not brand-style exclusivity.
• Accurate patent expiration, Orange Book status, litigation timelines, and numeric revenue projections cannot be completed from the information provided.

FAQs

1) Is dorzolamide hydrochloride/timolol maleate still prescribed for ocular hypertension and primary open-angle glaucoma?

Yes. The combination remains within established topical IOP-lowering strategies and is routinely used in chronic ophthalmic care.

2) Do generics replace brand dorzolamide/timolol products automatically?

In many settings, generic substitution is permitted and common, and payer formularies generally favor low-cost alternatives, subject to local pharmacy and plan rules.

3) Are there any biosimilars for dorzolamide/timolol?

No. It is a small-molecule ophthalmic drug combination, not a biologic.

4) What are the main safety or tolerability issues that influence switching?

Ocular irritation and stinging are common topical tolerability considerations that can drive adherence issues and switching within IOP-lowering regimens.

5) What data source is best for building a numeric market projection for this drug?

A paid dataset that provides unit volume and net pricing by geography and channel (e.g., IQVIA or equivalent) plus a modeled assumption set for future generic entry timing and net price erosion.

References

1. FDA. Approved Drug Products: Search Orange Book. U.S. Food and Drug Administration.
2. ClinicalTrials.gov. Dorzolamide hydrochloride; timolol maleate search results. National Library of Medicine.
3. EMA. European public assessment reports and EPAR search portal. European Medicines Agency.