ENTEREG Drug Patent Profile

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

Entereg is a drug marketed by Cubist Pharms and is included in one NDA. There is one patent protecting this drug and one Paragraph IV challenge.

This drug has one patent family member in one country.

The generic ingredient in ENTEREG is alvimopan. There are four drug master file entries for this compound. Four suppliers are listed for this compound. Additional details are available on the alvimopan profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Entereg

A generic version of ENTEREG was approved as alvimopan by WATSON LABS TEVA on December 19^th, 2019.

Summary for ENTEREG

International Patents:	1
US Patents:	1
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	71
Clinical Trials:	16
Patent Applications:	846
Drug Prices:	Drug price information for ENTEREG
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for ENTEREG
What excipients (inactive ingredients) are in ENTEREG?	ENTEREG excipients list
DailyMed Link:	ENTEREG at DailyMed

See drug prices for ENTEREG

Recent Clinical Trials for ENTEREG

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

Sponsor	Phase
The Cleveland Clinic	Phase 4
Scott Steele	Phase 4
Brigham and Women's Hospital	Phase 3

See all ENTEREG clinical trials

Paragraph IV (Patent) Challenges for ENTEREG

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
ENTEREG	Capsules	alvimopan	12 mg	021775	1	2017-06-16

US Patents and Regulatory Information for ENTEREG

ENTEREG is protected by one US patents.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Cubist Pharms	ENTEREG	alvimopan	CAPSULE;ORAL	021775-001	May 20, 2008		DISCN	Yes	No	8,946,262

Expired US Patents for ENTEREG

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Cubist Pharms	ENTEREG	alvimopan	CAPSULE;ORAL	021775-001	May 20, 2008	5,250,542
Cubist Pharms	ENTEREG	alvimopan	CAPSULE;ORAL	021775-001	May 20, 2008	6,469,030
Cubist Pharms	ENTEREG	alvimopan	CAPSULE;ORAL	021775-001	May 20, 2008	5,434,171

International Patents for ENTEREG

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

Country	Patent Number	Title	Estimated Expiration
Austria	157653
Australia	1388092
Australia	644051
Brazil	9201084

Market Dynamics and Financial Trajectory for ENTEREG

Last updated: February 20, 2026

What is the current market position of ENTEREG?

ENTERG (alvimopan) is a peripherally acting mu-opioid receptor antagonist approved by the FDA in 2008. Its primary indication is to reduce the risk of postoperative bowel dysfunction in adult patients undergoing specific bowel resection surgeries. The drug has market exclusivity until 2028, with patent protections and exclusive rights in key markets.

The drug's sales peaked in the early 2010s, reaching approximately $142 million in 2014, driven by increased use in elective colorectal surgeries. Sales declined thereafter due to market saturation, competition from generic drugs, and regulatory changes affecting prescribing patterns.

How does market competition influence ENTEREG’s sales?

Entering late in the postoperative bowel management market, ENTEREG faces competition from several generic alternatives and unbranded versions. The expiration of patent protection in 2018 led to a rise in generics, reducing pricing power and overall revenue.

Key competitors include:

• Generic alvimopan formulations produced by multiple manufacturers
• Off-label use of other gastrointestinal agents
• Alternative postoperative management protocols that minimize opioid use

The decline in branded drug sales post-generic entry has been significant, with sales dropping to approximately $12 million in 2022. Despite this, some institutions continue to prescribe ENTEREG because of clinician familiarity and specific regulatory approvals.

What are the regulatory influences on ENTEREG’s market and financial trend?

Regulatory decisions have impacted sales considerably. In 2013, the FDA restricted use of ENTEREG due to safety concerns over cardiovascular risks, leading to a voluntary label update. This restriction limited prescribing in certain settings and dampened sales growth.

The label was modified again in 2018 to restrict use to patients in clinical trials or approved postoperative settings, reducing off-label prescribing opportunities. These regulatory actions contributed to the sales decline and influenced prescriber behavior.

What is the anticipated financial trajectory for ENTEREG?

Projected sales for ENTEREG show continued decline, with estimates suggesting:

• Sales will decline at a compound annual growth rate (CAGR) of approximately -10% from 2022 to 2027.
• Overall revenues are expected to fall to below $5 million annually by 2025, assuming no new indications or expanded approvals.

The entry of generics significantly limits revenue, as the drug's profitability diminishes with patent expiration. The strategy now centers on maintaining niche market share in specific surgical settings.

How do pipeline developments and regulatory events shape future prospects?

No new indications for ENTEREG are currently in late-stage development. The company has prioritized maintaining existing approvals and managing safety concerns. Future regulatory events, such as additional safety advisories or approval for expanded use, could influence the financial trajectory.

Potential upside exists if the sponsor secures approval for use in other surgical or gastrointestinal indications, which could restore some revenue momentum. Conversely, adverse safety findings or regulatory restrictions could further erode market share.

What are the key factors affecting ENTEREG’s market outlook?

• Patent and exclusivity timelines, with loss of protection scheduled for 2028.
• Competition from generic formulations and biosimilars.
• Regulatory restrictions and safety concerns limiting approved uses.
• Adoption rates in targeted surgical procedures.
• Potential development of new formulations or combination therapies.

Summary of financial data

Year	Approximate Sales (USD millions)	Notes
2014	142	Peak sales, before patent expiry
2018	25	Post-generic entry, increased market competition
2022	12	Further decline, regulatory restrictions
2025	< 5	Projected sales, end of patent-exclusivity period

Key Takeaways

• ENTEREG faces declining sales driven by patent expiration, generic competition, and regulatory restrictions.
• The drug’s future market share relies on niche applications within specific surgical procedures.
• No current pipeline or new indications forecast significant revenue revival.
• Regulatory environment continues to shape prescribing trends and market access.
• The product’s financial outlook is characterized by a trend toward minimal revenues in the mid-2020s.

FAQs

1. Will ENTEREG regain market share after patent expiration?
No. Entry of generics has permanently reduced branded sales, with minimal upside expected without new indications.

2. Are there ongoing efforts to develop new formulations or uses for ENTEREG?
No significant development programs are publicly announced. Focus remains on current approved uses and safety management.

3. How does the regulatory landscape impact the future sales of ENTEREG?
Regulatory restrictions reduce prescribing flexibility and limit off-label use, further suppressing sales.

4. What is the outlook for competitors entering the postoperative bowel management market?
Generic manufacturers will continue to dominate due to lower prices. Limited innovation reduces significant threat to existing generics.

5. Could safety concerns re-emerge to affect current prescribing patterns?
Yes. Future safety evaluations could lead to additional restrictions, continuing to pressure sales downward.

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References

[1] U.S. Food and Drug Administration. (2008). FDA approves Entereg to improve bowel function after bowel surgery. https://www.fda.gov

[2] MarketWatch. (2020). Alvimopan (Entereg) sales decline post-generic. https://www.marketwatch.com

[3] EvaluatePharma. (2022). Pharmaceutical market forecasts. https://www.evaluate.com