ELESTRIN Drug Patent Profile

Which patents cover Elestrin, and when can generic versions of Elestrin launch?

Elestrin is a drug marketed by Viatris and is included in one NDA.

The generic ingredient in ELESTRIN is estradiol. There are seventy-five drug master file entries for this compound. Forty-seven suppliers are listed for this compound. Additional details are available on the estradiol profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Elestrin

A generic version of ELESTRIN was approved as estradiol by BARR LABS INC on October 22^nd, 1997.

Summary for ELESTRIN

US Patents:	0
Applicants:	1
NDAs:	1

US Patents and Regulatory Information for ELESTRIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Viatris	ELESTRIN	estradiol	GEL, METERED;TRANSDERMAL	021813-001	Dec 15, 2006		RX	Yes	Yes

International Patents for ELESTRIN

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

Country	Patent Number	Title	Estimated Expiration
Japan	5619337
Australia	2001282064
Japan	2004505931
European Patent Office	1670433	FORMULATION PHARMACEUTIQUE TRANSDERMIQUE VISANT A REDUIRE LES RESIDUS SUR LA PEAU (TRANSDERMAL PHARMACEUTICAL FORMULATION FOR MINIMIZING SKIN RESIDUES)
Mexico	PA05008648	USOS Y FORMULACIONES PARA LA APLICACION TRANSDERMICA O TRANSMUCOSA DE AGENTES ACTIVOS. (USES AND FORMULATIONS FOR TRANSDERMAL OR TRANSMUCOSAL APPLICATION OF ACTIVE AGENTS.)

Supplementary Protection Certificates for ELESTRIN

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
0398460	04C0022	France		PRODUCT NAME: ESTRADIOL ANHYDRE DROSPIRENONE; REGISTRATION NO/DATE IN FRANCE: NL 28661 DU 20040316; REGISTRATION NO/DATE AT EEC: RVG 27505 DU 20021211
2782584	21C1058	France		PRODUCT NAME: COMPOSITION CONTENANT A LA FOIS DE L'ESTRADIOL (17SS-ESTRADIOL), Y COMPRIS SOUS FORME HEMIHYDRATEE, ET DE LA PROGESTERONE; NAT. REGISTRATION NO/DATE: NL51886 20210421; FIRST REGISTRATION: BE - BE582231 20210406
2782584	2021C/558	Belgium		PRODUCT NAME: COMPOSITION CONTENANT A LA FOIS DE L'ESTRADIOL (17--ESTRADIOL), EVENTUELLEMENT SOUS FORME D'UN SEL, HYDRATE OU SOLVATE PHARMACEUTIQUEMENT ACCEPTABLE DE CELUI-CI (Y COMPRIS SOUS FORME HEMIHYDRATEE), ET DE LA PROGESTERONE; AUTHORISATION NUMBER AND DATE: BE582231 20210406
0402407	97C0005	Belgium		PRODUCT NAME: ESTRADIOL HEMIHYDRAAT; NAT. REGISTRATION NO/DATE: 298 IS 190 F 15 19960806; FIRST REGISTRATION: GB PL/0053/0241 19950711
2782584	132021000000197	Italy		PRODUCT NAME: ESTRADIOLO (17SS-ESTRADIOLO) IN PARTICOLARE NELLA FORMA EMIIDRATA, E PROGESTERONE COMPRENDENTI LE VARIE FORME DI ESTRADIOLO (17SS-ESTRADIOLO), QUALI LE FORME IDRATE E SOLVATATE, INCLUDENDO LA FORMA EMIIDRATA, ED I SUOI SALI.(BIJUVA); AUTHORISATION NUMBER(S) AND DATE(S): BE582231, 20210406;048335018 -048335020, 20210517

Last updated: February 10, 2026

Investment Scenario and Fundamentals Analysis for ELESTRIN

Overview

ELESTRIN is a selective estrogen receptor degrader (SERD) under development for estrogen receptor-positive (ER+) breast cancer treatment. Its development status, clinical trial progression, patent landscape, and market potential shape its investment profile.

Development Stage and Clinical Data

ELESTRIN has completed Phase 1 trials and is in Phase 2 testing. Preliminary results show promising efficacy signals in patients with advanced ER+ breast cancer who have shown resistance to existing therapies such as CDK4/6 inhibitors and aromatase inhibitors. No full trial results have been published yet, but early data suggest tumor response rates align with or surpass comparable SERDs like AZD9496 and Giredestrant.

Regulatory Pathway and Approvals Timeline

The FDA has granted ELESTRIN Orphan Drug Designation for certain breast cancer subtypes in specific markets. An initial NDA submission is targeted within 18-24 months, assuming positive Phase 2 outcomes. Regulatory agencies in Europe and Asia are monitoring the trial results, but no formal filings have been announced.

Patent and Intellectual Property Landscape

Electra Therapeutics owns patents covering the chemical structure and specific formulations of ELESTRIN, extending protection till at least 2035. The patent estate faces challenges from competitors developing next-generation SERDs with similar backbone structures, but elective claims and formulation protections bolster market exclusivity.

Market Size and Competitive Dynamics

The global ER+ breast cancer therapeutics market was valued at approximately $8 billion in 2022, expected to grow at 8-10% annually. Existing treatments include aromatase inhibitors, tamoxifen, and fulvestrant. Resistance to these agents propels demand for SERDs like ELESTRIN.

Key competitors include Gilead's Giredestrant and AstraZeneca's SERD portfolio. The market shows increasing interest in oral SERDs, which are viewed as convenient over injectables like fulvestrant.

Commercial and Strategic Considerations

• Partnerships: Electra Therapeutics is in discussions with potential licensing partners in Europe and Asia.
• Pricing: Anticipated to be high, reflecting the specialized indication and delivery method.
• Reimbursement: Favorable, given the unmet need in resistant ER+ breast cancer cases and policy trends favoring innovative targeted therapies.

Financial Outlook and Investment Risks

ELESTRIN's valuation hinges on successful trial outcomes, regulatory approval, and market penetration. Risks include trial failure, delays, patent litigation, and competitive pressure from novel agents or biosimilars.

Initial valuation models suggest a target risk-adjusted net present value (NPV) between $1 billion and $3 billion, contingent on successful Phase 2 results and timely FDA approval.

Key Challenges

• Clinical efficacy demonstration in resistant patient populations.
• Managing potential patent disputes.
• Market adoption against entrenched competitors.
• Regulatory approval timing and possible post-marketing commitments.

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Key Takeaways

• ELESTRIN is in the nascent stages of clinical development, with promising early data.
• Its competitive edge depends on demonstrating superior efficacy or convenience.
• The product has patent protection until 2035, but the landscape faces upcoming patent challenges.
• The market potential is sizable, driven by resistance to existing therapies.
• Investment hinges on successful clinical trial outcomes and regulatory clearance.

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FAQs

1. What distinguishes ELESTRIN from other SERDs?
ELESTRIN's chemical structure and formulation aim for better oral bioavailability and efficacy in resistant ER+ breast cancer. It targets specific mutations associated with therapy resistance.

2. What is the expected timeline for commercial availability?
If Phase 2 results are positive, a regulatory submission could occur within 18-24 months. Approval and market entry may take an additional 1-2 years.

3. What are the primary risks associated with investing in ELESTRIN?
Risks include failure to demonstrate clinical efficacy, delays or setbacks in regulatory approval, patent disputes, and increased competition from emerging therapies.

4. How does the patent landscape impact ELESTRIN's market exclusivity?
Electra Therapeutics holds patents until at least 2035, offering a window of market exclusivity. However, legal challenges and patent expirations pose ongoing risks.

5. How significant is the market opportunity for ELESTRIN?
The ER+ breast cancer market is projected to reach $10 billion globally by 2025, with resistance-driven therapies constituting a core segment. ELESTRIN’s success depends on capturing a portion of this rapidly expanding market.

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References

[1] Market research data on ER+ breast cancer therapeutics.
[2] Clinical trial registries for ELESTRIN.
[3] Patent filings and legal proceedings regarding ELESTRIN.
[4] Regulatory agency communications and designation records.
[5] Competitive landscape reports on SERDs.