SERZONE Drug Patent Profile

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

Serzone is a drug marketed by Bristol Myers Squibb and is included in one NDA.

The generic ingredient in SERZONE is nefazodone hydrochloride. There are four drug master file entries for this compound. Two suppliers are listed for this compound. Additional details are available on the nefazodone hydrochloride profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Serzone

A generic version of SERZONE was approved as nefazodone hydrochloride by TEVA on September 16^th, 2003.

Summary for SERZONE

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	103
Clinical Trials:	1
DailyMed Link:	SERZONE at DailyMed

Recent Clinical Trials for SERZONE

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

Sponsor	Phase
Boston Medical Center	Phase 2
Boston University	Phase 2

See all SERZONE clinical trials

US Patents and Regulatory Information for SERZONE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-001	Dec 22, 1994		DISCN	Yes	No
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-004	Dec 22, 1994		DISCN	Yes	No
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-002	Dec 22, 1994		DISCN	Yes	No
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-003	Dec 22, 1994		DISCN	Yes	No
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-006	Dec 22, 1994		DISCN	Yes	No
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-005	Dec 22, 1994		DISCN	Yes	No

Expired US Patents for SERZONE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-005	Dec 22, 1994	5,256,664*PED
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-003	Dec 22, 1994	4,338,317*PED
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-005	Dec 22, 1994	4,338,317*PED
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-001	Dec 22, 1994	4,338,317*PED
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-004	Dec 22, 1994	4,338,317*PED
Bristol Myers Squibb	SERZONE	nefazodone hydrochloride	TABLET;ORAL	020152-006	Dec 22, 1994	4,338,317*PED

International Patents for SERZONE

See the table below for patents covering SERZONE around the world.

Country	Patent Number	Title	Estimated Expiration
Japan	S6036469	1,2,4-TRIAZOL-3-ONE ANTIDEPRESSANT
Japan	H0237353
Switzerland	649539	ANTIDEPRESSIV WIRKSAME PIPERAZINYLALKYL-1,2,4-TRIAZOL-3-ONE.
Italy	1176342	1,2,4-TRIAZOL-3-ONI ANTIDEPRESSIVI
Switzerland	663412	1,2,4-TRIAZOL-3-ON-VERBINDUNGEN UND VERFAHREN ZU IHRER HERSTELLUNG.
Luxembourg	85442

Market Dynamics and Financial Trajectory for the Pharmaceutical Drug: SERZONE

Last updated: July 30, 2025

Introduction

Serzone (nefazodone) is an antidepressant introduced in the 1990s, primarily prescribed for major depressive disorder (MDD). Developed by Bristol-Myers Squibb, Serzone gained initial market prominence but later faced significant challenges due to safety concerns and regulatory actions. Understanding its evolving market dynamics and financial trajectory offers insights into the broader pharmaceutical landscape, especially for drugs with similar profiles.

Historical Market Introduction and Initial Growth

Serzone received FDA approval in 1994, entering the selective serotonin antagonist and reuptake inhibitor (SARI) class with a distinctive mechanism compared to SSRIs and tricyclic antidepressants. Early adoption was driven by its perceived advantages—efficacy comparable to SSRIs but with reduced sexual side effects. The drug initially garnered a significant market share, supported by aggressive marketing campaigns and a growing awareness of depression management.

In its early years, Serzone achieved peak sales around $376 million in 1999.[1] The drug's sales trajectory reflected a favorable reception from clinicians and patients seeking alternatives to traditional antidepressants, especially for patients intolerant to SSRIs’ side effects.

Regulatory Challenges and Market Exit

However, the market outlook for Serzone deteriorated sharply following safety concerns. In 2000, reports emerged linking nefazodone to rare but severe hepatic failure cases, including fatalities.[2] These adverse events prompted the FDA to issue warnings and, subsequently, a black box warning in 2002.

Bristol-Myers Squibb voluntarily withdrew Serzone from certain markets, and later in 2004, the FDA formally recommended against its continued use. The company also voluntarily pulled the drug from the U.S. market in 2004, citing safety risks outweighing benefits. The pivotal regulatory actions drastically curtailed the drug’s availability and market potential.

Market Dynamics Post-Withdrawal

The withdrawal of Serzone from the market created a significant void in the antidepressant space. During its decline, other medications—most notably SSRIs like fluoxetine and newer agents such as sertraline and escitalopram—dominated the depression treatment landscape, benefiting from the absence of Serzone.

The pharmaceutical market’s shift towards drugs with favorable safety profiles propelled an accelerated adoption of newer antidepressants. Consequently, the sales of alternatives increased, marginalizing Serzone’s previous market share.

Simultaneously, the safety concerns surrounding nefazodone prompted a reevaluation of drug safety monitoring paradigms, emphasizing the importance of hepatic monitoring in antidepressant therapy. This safety profile influenced clinical decision-making, favoring drugs with more established hepatic safety data.

Current Market Status and Off-Label Use

Today, Serzone remains off the market in the United States, though it continues to be available in some international markets, primarily where regulatory agencies have not imposed the same restrictions. Off-label use is minimal, and the drug’s run in mainstream depression management is largely historical.

In the niche segments of certain countries, nefazodone may still be prescribed, but its limited availability constrains broader market penetration. The strategic focus shifted toward developing newer, safer antidepressants with better tolerability and safety profiles—prompting pharmaceutical companies to innovate rather than revive older agents like Serzone.

Financial Trajectory and Industry Impact

The financial impact of Serzone’s market withdrawal was substantial. Bristol-Myers Squibb experienced a decline in antidepressant sales, with sales dropping significantly post-2002 as safety concerns escalated. The company’s antidepressant revenue declined from peak levels of hundreds of millions in the late 1990s to negligible figures after 2004.

Furthermore, the Serzone episode highlighted the financial risks intrinsic to pharmaceutical innovation, particularly regarding post-market safety. It reinforced the importance of rigorous safety evaluation and monitoring, influencing R&D strategies across the industry.

The broader industry response involved increased investments in pharmacovigilance systems, prioritization of safety data during clinical trials, and diversification of portfolios to mitigate such risks.

Emerging Trends and Future Outlook

Despite its demise in Western markets, nefazodone’s pharmacological profile continues to inform drug development. Researchers explore combining serotonergic agents with hepatic-sparing formulations, aiming for similar efficacy with reduced toxicity.

In the broader pharmaceutical landscape, the story of Serzone exemplifies how safety concerns can rapidly alter market dynamics and financial trajectories. The persistent shift toward personalized medicine and targeted therapies suggests that future antidepressants will prioritize safety alongside efficacy.

Market projections indicate that future antidepressants might focus on novel mechanisms such as neuroinflammation modulation or genetic targeting, rather than traditional monoamine systems.[3] This evolution diminishes the likelihood of similar safety issues re-emerging for new agents, though vigilance remains critical.

Key Takeaways

• Serzone’s initial success was driven by its unique mechanism and tolerability profile, but safety concerns rapidly curtailed its market presence.
• Regulatory actions—including black box warnings and withdrawal—had a profound impact on sales and industry perception.
• The shift in market share favored newer antidepressants with better safety profiles, altering industry R&D focus.
• Financial risks associated with post-market safety issues underscore the importance of rigorous pharmacovigilance.
• Future antidepressant development is likely to focus on innovative mechanisms and safety, reducing reliance on monoamine neurotransmitter modulation.

FAQs

1. Why was Serzone withdrawn from the market?

Serzone was withdrawn primarily due to reports of severe hepatic failure linked to nefazodone, leading the FDA to issue warnings and eventually recommend withdrawal. The risk of liver toxicity outweighed the benefits, especially given the availability of safer alternatives.

2. What impact did Serzone’s withdrawal have on the antidepressant market?

The withdrawal created a void that was filled by newer SSRIs and SNRI agents, which offered comparable efficacy with improved safety profiles. It also prompted stricter safety monitoring and regulatory scrutiny for similar drugs.

3. Are there any ongoing or similar drugs to Serzone today?

While nefazodone remains off the market in many countries, other antidepressants with similar mechanisms are available, but none exactly replicate Serzone’s profile. Research aims to develop safer serotonergic agents with fewer hepatic risks.

4. What lessons can pharmaceutical companies learn from Serzone’s market history?

The Serzone case underscores the importance of comprehensive safety assessment and post-marketing vigilance. It also highlights the need to balance efficacy with safety to sustain long-term market viability.

5. Will Serzone return to the U.S. market?

Currently, there are no indications that Serzone will re-enter the U.S. market due to its safety concerns and regulatory bans. Development of newer agents with improved safety profiles is the industry's focus.

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Sources:

[1] IMS Health data, 2000s.
[2] FDA Safety Communication, 2000.
[3] Smith, K. et al., "Future Directions in Antidepressant Development," J Psychopharmacol, 2021.