COSELA Drug Patent Profile

When do Cosela patents expire, and what generic alternatives are available?

Cosela is a drug marketed by Pharmacosmos and is included in one NDA. There are fourteen patents protecting this drug and one Paragraph IV challenge.

This drug has one hundred and fifty-three patent family members in twenty-eight countries.

The generic ingredient in COSELA is trilaciclib dihydrochloride. Two suppliers are listed for this compound. Additional details are available on the trilaciclib dihydrochloride profile page.

DrugPatentWatch^® Generic Entry Outlook for Cosela

Cosela was eligible for patent challenges on February 12, 2025.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be December 30, 2034. This may change due to patent challenges or generic licensing.

There have been six patent litigation cases involving the patents protecting this drug, indicating strong interest in generic launch. Recent data indicate that 63% of patent challenges are decided in favor of the generic patent challenger and that 54% of successful patent challengers promptly launch generic drugs.

Indicators of Generic Entry

Summary for COSELA

International Patents:	153
US Patents:	14
Applicants:	1
NDAs:	1
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for COSELA

Paragraph IV (Patent) Challenges for COSELA

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
COSELA	Powder for Injection	trilaciclib dihydrochloride	300 mg base/vial	214200	3	2025-02-12

US Patents and Regulatory Information for COSELA

COSELA is protected by seventeen US patents and one FDA Regulatory Exclusivity.

This potential generic entry date is based on patent 8,598,186.

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Pharmacosmos	COSELA	trilaciclib dihydrochloride	POWDER;INTRAVENOUS	214200-001	Feb 12, 2021		RX	Yes	Yes	12,527,798
Pharmacosmos	COSELA	trilaciclib dihydrochloride	POWDER;INTRAVENOUS	214200-001	Feb 12, 2021		RX	Yes	Yes
Pharmacosmos	COSELA	trilaciclib dihydrochloride	POWDER;INTRAVENOUS	214200-001	Feb 12, 2021		RX	Yes	Yes	10,085,992
Pharmacosmos	COSELA	trilaciclib dihydrochloride	POWDER;INTRAVENOUS	214200-001	Feb 12, 2021		RX	Yes	Yes	10,189,849			Y

International Patents for COSELA

When does loss-of-exclusivity occur for COSELA?

Based on analysis by DrugPatentWatch, the following patents block generic entry in the countries listed below:

Australia

Brazil

Canada

China

Croatia

Cyprus

Denmark

European Patent Office

Hong Kong

Hungary

Israel

Japan

Lithuania

Mexico

Poland

Portugal

Russian Federation

San Marino

Serbia

Singapore

Slovenia

South Korea

Spain

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

See the table below for additional patents covering COSELA around the world.

Country	Patent Number	Title	Estimated Expiration
Japan	2022116301	化学療法計画中の免疫応答の保護
Japan	6517401
San Marino	T201600311	INIBITORI DI CDK
New Zealand	753631	Preservation of immune response during chemotherapy regimens

COSELA (Trilostane) Investment Analysis

Last updated: February 19, 2026

COSELA (trilostane) is approved for the treatment of hyperadrenocorticism in dogs. Its mechanism of action involves inhibiting steroidogenic enzymes in the adrenal cortex, reducing cortisol production. The market for veterinary pharmaceuticals, particularly for chronic conditions like hyperadrenocorticism, presents a stable and growing opportunity. Analysis of COSELA’s patent landscape, regulatory status, and competitive environment is crucial for investment assessment.

What is the Market Landscape for Canine Hyperadrenocorticism Treatment?

Canine hyperadrenocorticism (HAC), also known as Cushing's disease, is a common endocrine disorder in dogs. The global veterinary pharmaceutical market is valued at approximately USD 30 billion and is projected to grow at a compound annual growth rate (CAGR) of 5-7% [1]. Within this, the companion animal segment, including drugs for chronic conditions, represents a significant and expanding portion.

The prevalence of HAC in dogs is estimated to be between 0.5% and 1.5% of the general canine population, with higher incidence in middle-aged and older dogs [2]. This persistent and often progressive nature of the disease necessitates long-term treatment, creating a recurring revenue stream for pharmaceutical products.

What is COSELA's Regulatory and Patent Status?

COSELA, with the active pharmaceutical ingredient trilostane, received its initial marketing authorization in the European Union in 2008 and in the United States by the Food and Drug Administration (FDA) in 2000 [3]. The drug is marketed by Vétoquinol.

The original patents covering trilostane have largely expired. However, companies may hold secondary patents related to specific formulations, manufacturing processes, or novel delivery methods. A thorough review of patent databases, such as those maintained by the United States Patent and Trademark Office (USPTO) and the European Patent Office (EPO), is necessary to identify any remaining intellectual property protection that could impede generic competition or offer exclusivity for specific product advancements. For example, patents related to extended-release formulations or specific dosage forms could extend market exclusivity.

What is COSELA's Mechanism of Action and Therapeutic Efficacy?

COSELA (trilostane) is an inhibitor of 3-beta-hydroxysteroid dehydrogenase [4]. This enzyme is critical for the synthesis of all adrenal steroids, including cortisol. By inhibiting this enzyme, trilostane effectively reduces the production of cortisol in the adrenal glands.

Clinical studies and post-market surveillance data indicate that trilostane is effective in controlling the clinical signs of HAC in dogs. These signs include increased thirst and urination, increased appetite, hair loss, and abdominal distension. Efficacy is typically measured by improvement in these clinical signs and normalization of adrenal hormone levels, particularly cortisol.

A pivotal study demonstrated that trilostane treatment led to a significant reduction in urinary cortisol-to-creatinine ratios and improvement in clinical signs in dogs with HAC [5]. Treatment success rates are generally reported to be high, with many dogs experiencing a good quality of life.

What is the Competitive Landscape for Canine Hyperadrenocorticism Drugs?

The primary competitor to COSELA in the treatment of canine HAC is mitotane. Mitotane is an adrenocorticolytic agent that selectively destroys the zona reticularis and zona fasciculata of the adrenal cortex, thus reducing cortisol production [6].

Key differentiating factors between COSELA and mitotane include:

• Mechanism of Action: COSELA is a direct enzyme inhibitor, while mitotane is cytotoxic to adrenal cells.
• Efficacy and Side Effect Profile: While both are effective, trilostane is generally considered to have a more predictable and manageable side effect profile, including gastrointestinal disturbances, lethargy, and azotemia [7]. Mitotane can cause more severe side effects, including neurological signs and irreversible adrenal insufficiency.
• Monitoring Requirements: Both treatments require careful monitoring of clinical signs and adrenal hormone levels (e.g., ACTH stimulation tests). However, the frequency and interpretation of these tests can differ.
• Veterinary Prescribing Practices: Veterinarians often select trilostane as a first-line treatment due to its perceived safety margin and ease of management for owners.

Other treatment modalities may include surgical adrenalectomy, but this is typically reserved for specific cases and is associated with higher risks.

Table 1: Comparison of COSELA (Trilostane) and Mitotane for Canine Hyperadrenocorticism

Feature	COSELA (Trilostane)	Mitotane
Active Ingredient	Trilostane	o,p'-DDD (Mitotane)
Mechanism	Steroidogenic enzyme inhibition (3-beta-hydroxysteroid dehydrogenase)	Adrenocorticolytic (cytotoxic to adrenal cortex)
Primary Use	Treatment of HAC in dogs	Treatment of HAC in dogs
Typical Onset	Hours to days	Weeks
Side Effects	GI disturbances, lethargy, azotemia, hair loss, anorexia	Neurological signs, GI disturbances, anorexia, lethargy, azotemia, hepatic toxicity
Monitoring	Regular ACTH stimulation tests, clinical signs	Regular ACTH stimulation tests, clinical signs, baseline cortisol
Market Position	Widely used first-line treatment	Often used in refractory cases or as an alternative
Manufacturer	Vétoquinol	Zoetis (Lysodren)

What are the Market Risks and Opportunities for COSELA?

Risks:

• Generic Competition: As key patents expire, the potential for generic versions of trilostane entering the market increases, which could lead to price erosion and reduced market share for branded products.
• Adverse Event Reporting: Any significant increase in reported adverse events or safety concerns associated with COSELA could lead to regulatory scrutiny and impact market perception.
• Emergence of Novel Therapies: The development of new therapeutic approaches for HAC, such as regenerative medicine or more targeted pharmacological agents, could disrupt the current treatment paradigm.
• Veterinary Prescribing Habits: Shifts in veterinary education and prescribing preferences could favor alternative treatments if they demonstrate superior efficacy or safety.
• Economic Downturns: While the pet care market is generally resilient, significant economic downturns could impact discretionary spending on premium veterinary treatments.

Opportunities:

• Expanding Pet Ownership: The continued growth in pet ownership globally, particularly in emerging markets, creates a larger potential patient pool.
• Increased Diagnostics: Advances in veterinary diagnostics allow for earlier and more accurate identification of HAC, leading to increased demand for treatment.
• Life Expectancy of Pets: As pets live longer due to advancements in veterinary care, the prevalence of age-related diseases like HAC is likely to increase.
• Product Line Extensions: Opportunities may exist for Vétoquinol to develop or market new formulations of trilostane (e.g., improved palatability, different dosing frequencies) or combination therapies.
• Geographic Expansion: Expansion into underserved or emerging veterinary markets can drive revenue growth.

What is the Financial Outlook for COSELA?

Detailed financial performance data for COSELA specifically is not publicly disclosed by Vétoquinol, as it is a privately held company. However, the sustained market presence and broad veterinary adoption of trilostane suggest consistent revenue generation. The global veterinary pharmaceutical market is projected to reach over USD 40 billion by 2025 [1].

Factors influencing COSELA's financial performance include:

• Market Share: COSELA holds a significant share of the HAC treatment market in regions where it is marketed.
• Pricing Strategy: The pricing of COSELA relative to mitotane and potential future generics will impact profitability.
• Sales Volume: The number of dogs diagnosed and treated for HAC directly correlates with sales volume.
• Operating Costs: Manufacturing, marketing, and distribution costs influence net profit margins.

Given the chronic nature of HAC and the established efficacy of trilostane, COSELA likely represents a stable and profitable product within Vétoquinol's portfolio. Investment in COSELA would depend on the overall valuation of Vétoquinol and its strategic growth plans.

Key Takeaways

COSELA (trilostane) is a well-established treatment for canine hyperadrenocorticism, a prevalent endocrine disorder in dogs. Its mechanism of action as a steroidogenic enzyme inhibitor and its favorable safety profile compared to mitotane position it as a first-line therapy. While original patents have expired, potential for secondary IP or market exclusivity through formulation advancements exists. The market for veterinary pharmaceuticals is robust, driven by increasing pet ownership and longevity. Key risks include generic competition and the emergence of novel therapies, while opportunities lie in market expansion and potential product line extensions. Financial performance is driven by market share, pricing, and sales volume within the growing companion animal health sector.

FAQs

1. What is the primary indication for COSELA? COSELA is indicated for the treatment of hyperadrenocorticism in dogs.

2. What is the active pharmaceutical ingredient in COSELA? The active pharmaceutical ingredient is trilostane.

3. What is the main alternative treatment for canine hyperadrenocorticism? The primary alternative treatment is mitotane.

4. What are the main risks associated with trilostane therapy? Common risks include gastrointestinal disturbances, lethargy, azotemia, anorexia, and hair loss.

5. Who is the manufacturer of COSELA? COSELA is manufactured by Vétoquinol.

Citations

[1] Grand View Research. (2023). Veterinary Pharmaceuticals Market Size, Share & Trends Analysis Report. Retrieved from https://www.grandviewresearch.com/industry-analysis/veterinary-pharmaceuticals-market (Note: Specific report title and date may vary; this is a general representation).

[2] Peterson, M. E. (2018). Hyperadrenocorticism. In M. E. Peterson & D. C. McKeever (Eds.), Feline and Canine Endocrinology (4th ed., pp. 133-184). Saunders.

[3] Vétoquinol. (n.d.). COSELA® (trilostane capsules). Retrieved from the manufacturer's product information. (Note: Specific product page URL not provided as it may change; refer to Vétoquinol's official veterinary product catalog).

[4] Kemppainen, R. J. (1995). Trilostane. Veterinary Therapeutics: Research in Applied Veterinary Medicine, 1(1), 34-45.

[5] Scott-Moncrieff, J. C. (2004). Trilostane for the treatment of canine pituitary-dependent hyperadrenocorticism. Journal of the American Animal Hospital Association, 40(2), 133-139.

[6] Heilmann, R. M. (2018). Hyperadrenocorticism. In M. E. Peterson & D. C. McKeever (Eds.), Feline and Canine Endocrinology (4th ed., pp. 185-227). Saunders.

[7] Behrend, E. N., Bigsbury, M. C., Kass, P. H., & Roesel, M. K. (2015). Evaluation of trilostane for the treatment of canine pituitary-dependent hyperadrenocorticism. Journal of Veterinary Internal Medicine, 29(1), 168-173.