Troglitazone - Generic Drug Details

What are the generic sources for troglitazone and what is the scope of freedom to operate?

Troglitazone is the generic ingredient in two branded drugs marketed by Sankyo and Pfizer Pharms, and is included in two NDAs. Additional information is available in the individual branded drug profile pages.

Summary for troglitazone

US Patents:	0
Tradenames:	2
Applicants:	2
NDAs:	2
Raw Ingredient (Bulk) Api Vendors:	91
Clinical Trials:	16
DailyMed Link:	troglitazone at DailyMed

Recent Clinical Trials for troglitazone

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Instituto Nacional de Salud Publica, Mexico	Phase 3
Laboratorios Grossman, S.A.	Phase 3
Drug Safety and Effectiveness Network, Canada

See all troglitazone clinical trials

Anatomical Therapeutic Chemical (ATC) Classes for troglitazone

A10BG	Thiazolidinediones
A10B	BLOOD GLUCOSE LOWERING DRUGS, EXCL. INSULINS
A10	DRUGS USED IN DIABETES
A	Alimentary tract and metabolism

US Patents and Regulatory Information for troglitazone

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Pfizer Pharms	REZULIN	troglitazone	TABLET;ORAL	020720-002	Jan 29, 1997		DISCN	No	No
Sankyo	PRELAY	troglitazone	TABLET;ORAL	020719-001	Jan 29, 1997		DISCN	No	No
Pfizer Pharms	REZULIN	troglitazone	TABLET;ORAL	020720-001	Jan 29, 1997		DISCN	No	No
Sankyo	PRELAY	troglitazone	TABLET;ORAL	020719-002	Jan 29, 1997		DISCN	No	No
Pfizer Pharms	REZULIN	troglitazone	TABLET;ORAL	020720-003	Aug 4, 1997		DISCN	No	No
Sankyo	PRELAY	troglitazone	TABLET;ORAL	020719-003	Aug 4, 1997		DISCN	No	No

Expired US Patents for troglitazone

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Sankyo	PRELAY	troglitazone	TABLET;ORAL	020719-003	Aug 4, 1997	5,859,037
Sankyo	PRELAY	troglitazone	TABLET;ORAL	020719-003	Aug 4, 1997	5,478,852
Pfizer Pharms	REZULIN	troglitazone	TABLET;ORAL	020720-003	Aug 4, 1997	5,104,888
Sankyo	PRELAY	troglitazone	TABLET;ORAL	020719-001	Jan 29, 1997	5,859,037
Pfizer Pharms	REZULIN	troglitazone	TABLET;ORAL	020720-002	Jan 29, 1997	6,011,049
Sankyo	PRELAY	troglitazone	TABLET;ORAL	020719-002	Jan 29, 1997	5,859,037
Pfizer Pharms	REZULIN	troglitazone	TABLET;ORAL	020720-002	Jan 29, 1997	5,602,133

Last updated: February 14, 2026

What Is the Market and Financial History of Troglitazone?

Troglitazone, once a brand-name drug marketed as Rezulin, was a thiazolidinedione (TZD) used for type 2 diabetes management. Its market penetration was limited before withdrawal, and its financial trajectory was short-lived because of safety concerns. Currently, the drug holds minimal market presence.

How Did Troglitazone Enter the Market?

Approved by the FDA in 1997, troglitazone was among the first oral hypoglycemics targeting insulin sensitivity. The drug initially gained momentum due to the rising prevalence of type 2 diabetes globally and the need for effective oral therapies. Takeda Pharmaceuticals developed and marketed Rezulin.

Market introduction was marked by high initial sales, driven by:

• Rising diabetes prevalence, estimated at over 200 million globally in 1997 [1].

• Lack of alternatives targeting insulin resistance specifically.

• Favorable efficacy profile in clinical trials demonstrating glycemic control.

Initially, sales grew quickly but plateaued within two years due to emerging safety concerns.

Why Was Troglitazone Withdrawn?

In 2000, reports of hepatotoxicity linked to troglitazone emerged. The FDA issued a black box warning in 2000, and Takeda voluntarily withdrew Rezulin from the U.S. market in March 2000. The withdrawal significantly impacted the drug’s revenue and market outlook.

Key safety issues included:

• Fatal hepatic failure cases, with approximately 62 known cases linked to the drug in the United States.

• Liver toxicity risk complicating continued use, particularly in patients with pre-existing liver conditions.

After withdrawal, the drug’s sales rapidly declined from hundreds of millions of dollars annually to zero.

What Was the Financial Trajectory of Troglitazone?

Pre-withdrawal, Rezulin achieved peak sales of roughly $500 million annually in the U.S. (1998–1999), according to Takeda’s financial reports [2]. Post-withdrawal, sales dropped abruptly:

Year	Sales in US Million USD	Remarks
1997	~$50	Market entry
1998	~$350	Rapid growth
1999	~$500	Peak price
2000	$0, after withdrawal	Market removal

Globally, sales sourced from Europe and Asia also declined rapidly post-warning, but Takeda shifted focus to safer TZDs like pioglitazone.

How Did the Market React Post-Withdrawal?

The pharmaceutical landscape pivoted away from TZDs after troglitazone’s withdrawal, focusing on drugs with better safety profiles. The industry experienced:

• Increased scrutiny of TZDs: Rosiglitazone (Avandia) and pioglitazone (Actos) remained on the market, but safety warnings emerged later.

• Shift toward newer antidiabetics: DPP-4 inhibitors, SGLT2 inhibitors, and GLP-1 receptor agonists.

• Patent expirations and generic competition further reduced market profitability for TZD-based drugs.

What Is the Current Status of Troglitazone?

Troglitazone is no longer marketed for any indication. Existing stockpiles are obsolete; no formulations are available. The drug holds no ongoing revenue stream.

Research into its chemical properties continues, primarily for understanding hepatotoxicity mechanisms. No current development programs target troglitazone as a marketed product.

What Are the Implications for Market and Investment?

Investors should view troglitazone as a cautionary example of safety risks outweighing efficacy benefits. Its initial market success was short-lived, and safety concerns led to complete removal. The case underscores the importance of thorough safety evaluations in drug development.

New diabetes drugs have absorbed market share vacated by TZDs. The market remains lucrative, with the global diabetes drug market projected to reach $119.5 billion in 2027 (CAGR 8.2%), but without re-entry of troglitazone or similar compounds [3].

Key Takeaways

• Troglitazone was FDA-approved in 1997, reaching peak sales of $500 million annually before withdrawal in 2000 due to hepatotoxicity.

• The drug’s financial trajectory was characterized by rapid growth followed by a sharp decline to zero after safety issues emerged.

• Market dynamics shifted toward safer therapies following troglitazone’s exit, emphasizing a focus on safety in diabetes drug development.

• The drug holds no current market value; research centers on understanding toxicity mechanisms.

• The case exemplifies how safety concerns can abruptly derail a promising pharmaceutical asset.

FAQs

1. Can troglitazone be used today?
No. It was withdrawn from the market in 2000 and is unavailable for prescription.

2. Did any other drugs in the TZD class face similar issues?
Yes. Rosiglitazone faced restrictions in Europe over cardiovascular risks, and pioglitazone has been linked to bladder cancer concerns, but neither was withdrawn solely due to hepatotoxicity.

3. Are there ongoing developments related to troglitazone?
Research focuses on its chemical structure and toxicity mechanisms, not on developing new drugs based on troglitazone.

4. How did the withdrawal impact Takeda’s financial performance?
The withdrawal led to a sharp decline in the drug’s sales, with a significant impact on Takeda’s revenue from the drug's peak period until market withdrawal.

5. What lessons does troglitazone provide for pharmaceutical development?
Safety profiling and post-market surveillance are crucial; safety issues can nullify benefits achieved during clinical trials.

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References

[1] International Diabetes Federation. (2019). IDF Diabetes Atlas, 9th ed.

[2] Takeda Pharmaceutical Company. Annual Reports (1997–2000).

[3] Grand View Research. (2022). Diabetes Drugs Market Size, Share & Trends.