FASLODEX Drug Patent Profile

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

Faslodex is a drug marketed by Astrazeneca and is included in one NDA.

The generic ingredient in FASLODEX is fulvestrant. There are twelve drug master file entries for this compound. Twenty-two suppliers are listed for this compound. Additional details are available on the fulvestrant profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Faslodex

A generic version of FASLODEX was approved as fulvestrant by AMNEAL on March 4^th, 2019.

Summary for FASLODEX

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	86
Clinical Trials:	167
Patent Applications:	6,457
Drug Prices:	Drug price information for FASLODEX
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for FASLODEX
What excipients (inactive ingredients) are in FASLODEX?	FASLODEX excipients list
DailyMed Link:	FASLODEX at DailyMed

See drug prices for FASLODEX

Recent Clinical Trials for FASLODEX

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

Sponsor	Phase
University of California, San Diego	PHASE2
Eric Solutions LLC	PHASE1
Clinexcel Research, Ahmedabad, India	PHASE1

See all FASLODEX clinical trials

Pharmacology for FASLODEX

Drug Class	Estrogen Receptor Antagonist
Mechanism of Action	Estrogen Receptor Antagonists Selective Estrogen Receptor Modulators

Paragraph IV (Patent) Challenges for FASLODEX

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
FASLODEX	Injection	fulvestrant	50 mg/mL, 2.5 mL and 5 mL syringe	021344	1	2009-10-01

US Patents and Regulatory Information for FASLODEX

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Astrazeneca	FASLODEX	fulvestrant	SOLUTION;INTRAMUSCULAR	021344-002	Apr 25, 2002		DISCN	Yes	No
Astrazeneca	FASLODEX	fulvestrant	SOLUTION;INTRAMUSCULAR	021344-001	Apr 25, 2002	AO	RX	Yes	Yes

Expired US Patents for FASLODEX

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Astrazeneca	FASLODEX	fulvestrant	SOLUTION;INTRAMUSCULAR	021344-001	Apr 25, 2002

EU/EMA Drug Approvals for FASLODEX

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Mylan Pharmaceuticals Limited	Fulvestrant Mylan	fulvestrant	EMEA/H/C/004649Fulvestrant is indicated for the treatment of estrogen receptor positive, locally advanced or metastatic breast cancer in postmenopausal women:not previously treated with endocrine therapy, orwith disease relapse on or after adjuvant anti-estrogen therapy, or disease progression on antiestrogen therapy.	Authorised	yes	no	no	2018-01-08
AstraZeneca AB	Faslodex	fulvestrant	EMEA/H/C/000540Faslodex is indicated, , , as monotherapy for the treatment of estrogen receptor positive, locally advanced or metastatic breast cancer in postmenopausal women:, , not previously treated with endocrine therapy, or, with disease relapse on or after adjuvant antiestrogen therapy, or disease progression on antiestrogen therapy., , , in combination with palbociclib for the treatment of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative locally advanced or metastatic breast cancer in women who have received prior endocrine therapy., , , In pre- or perimenopausal women, the combination treatment with palbociclib should be combined with a luteinizing hormone releasing hormone (LHRH) agonist.,	Authorised	no	no	no	2004-03-09

International Patents for FASLODEX

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

Country	Patent Number	Title	Estimated Expiration
Austria	35814
Germany	122004000011
Germany	3472792
European Patent Office	0138504	STEROID DERIVATIVES
United Kingdom	8327256

Supplementary Protection Certificates for FASLODEX

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
0138504	SPC/GB04/009	United Kingdom		PRODUCT NAME: FULVESTRANT OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF.; REGISTERED: UK EU/1/03/269/001 20040310
0138504	91068	Luxembourg		91068, EXPIRES: 20091002
0138504	300158	Netherlands		300158, 20041002, EXPIRES: 20091001
0138504	2004C/004	Belgium		PRODUCT NAME: FULVESTRANT; REGISTRATION NO/DATE: EU/1/03/269/001 20040311

FASLODEX (fulvestrant) Market Dynamics and Financial Trajectory: Exclusivity Timeline, Patent/Orange Book Status, and Competitive Economics

Last updated: June 22, 2026

Executive summary

• FASLODEX (fulvestrant) is an established breast cancer endocrine therapy with major U.S. commercial visibility driven by metastatic ER+ disease and postmenopausal settings; the product’s longer-term economics depend on (1) fulvestrant patent and exclusivity cliffs, (2) switch dynamics between FASLODEX and oral SERDs, and (3) competitive positioning versus biosimilars/alternatives in injection pipelines.
• Market dynamics since 2020 have increasingly reflected the SERD category shift, with oral fulvestrant-like mechanisms changing prescribing patterns at the margin, while FASLODEX remains anchored where injectable fulvestrant is preferred or used per guidelines and payer pathways.
• Financial trajectory hinges on continued share retention post-expiration of the core fulvestrant exclusivity, plus resilience from dosing convenience and clinical adoption in specific lines of therapy.
• From a risk perspective, the key commercial threat is not “loss of exclusivity” alone, but sustained category displacement by oral SERDs that can compress FASLODEX’s addressable market even when injectable fulvestrant remains available.

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FASLODEX market dynamics: what drives adoption of fulvestrant in metastatic ER+ breast cancer?

FASLODEX’s demand drivers are tied to disease setting, clinical guideline fit, and how quickly oral SERDs shift treatment algorithms.

Which patients and lines of therapy support fulvestrant revenue?

Fulvestrant is used across ER-positive, HER2-negative metastatic breast cancer settings, commonly after progression on endocrine therapy. Commercially, this maps to:

• Postmenopausal women and adult patients where endocrine-based sequencing is standard
• Populations progressing on prior endocrine therapy (including aromatase inhibitor resistance patterns)
• Clinical settings where injectable therapy is a practical option or where oral SERDs are not the default

How do oral SERDs change FASLODEX prescribing behavior?

The emergence of oral SERDs creates a substitution pressure point:

• Oral administration can reduce clinic burden and improve patient preference
• Payers often steer toward oral options if labeled evidence and reimbursement favor them
• Clinician uptake can shift “next-line” choices away from injectables, even if fulvestrant remains effective

Net market impact: FASLODEX’s growth ceiling becomes more constrained. The product can hold revenue where injectable fulvestrant remains preferred or clinically established, but category displacement can reduce incremental expansion.

What role do payer policies and site-of-care economics play?

• Injectable SERDs create a reimbursement model tied to administration and infusion/clinic workflows.
• Oral SERDs shift costs to pharmacy benefit tiers and can benefit from stronger pharmacy formulary positioning.
• Patient assistance programs and contracting can smooth revenue but do not eliminate category substitution effects.

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When does FASLODEX lose exclusivity and what is the impact on pricing and volume?

Commercial trajectory post-exclusivity depends on how quickly competitive entries occur and whether biosimilar-like or generic-like substitution is feasible in practice for an injectable.

Exclusivity and competitive entry mechanics

For fulvestrant, the practical exclusivity risk is driven by:

• Patent expiration schedules covering compound, formulations, and delivery/administration-specific patents
• Any supplementary protections that can extend exclusivity windows
• Launch timing of competing fulvestrant generics or “authorized” supply, if applicable
• Regulatory labeling scope and interchangeability decisions

Market implication: Even after exclusivity gaps, price erosion usually depends on:

• Number of entrants
• Evidence strength for switching (comparability, tolerability, delivery device equivalence)
• Payer contracting dynamics and tender outcomes

How does the injector format affect generic adoption?

FASLODEX is a long-established injectable. For any follow-on product, adoption depends on:

• Confidence in pharmacokinetic and therapeutic equivalence
• Needle/syringe device familiarity
• Clinician and nursing acceptance
• Pharmacy and procurement contracting terms for the same dosing regimen

Net effect: Even with regulatory approval, adoption can lag if procurement and clinical workflow integration take time. That lag can smooth revenue decline relative to an immediate “therapeutic substitution” scenario.

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What patents protect FASLODEX (fulvestrant) and how strong is the patent estate?

Important constraint: A complete, accurate patent estate map requires a specific, current Orange Book–linked listing and litigation/patent number set. Without a verified patent-by-patent dataset for fulvestrant listings, any detailed count of patents, expiration dates, and jurisdictional coverage would risk being incomplete or incorrect.

Therefore, no patent-strength or expiration timeline table is provided here.

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What is the Orange Book status of FASLODEX and which exclusivities matter most?

Important constraint: Orange Book status depends on the exact NDC/NDA listing, listed patents, and exclusivity codes tied to that specific approval record. Without a verified Orange Book listing extract for FASLODEX, providing codes, listed patent numbers, or exclusivity end dates would risk accuracy issues.

Therefore, no Orange Book status table is provided here.

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What generic entry risks exist for FASLODEX and what does launch look like in practice?

Entry risk is less about “approval possibility” and more about commercialization execution:

• Whether FDA approval permits the same dosing and administration approach
• Whether label language supports the same lines of therapy
• Whether payers view the product as therapeutically interchangeable
• Whether wholesalers and group purchasing organizations (GPOs) prefer a new SKU

Commercially, launch scenarios typically follow one of two paths:

1. Rapid contracting and substitution: quicker share loss and faster price pressure
2. Slow adoption with tender-based switching: sustained but declining sales as contracts renew

For FASLODEX, the long-established clinic workflow can create inertia, which can slow share erosion even if supply competition starts.

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FASLODEX competitive landscape: how does fulvestrant compare with competing SERDs and endocrine therapies?

FASLODEX competes both within injectable SERDs and across the broader ER-positive endocrine treatment landscape.

Direct class competition (injectable SERD vs oral SERD)

• Oral SERDs can capture incremental patients who would otherwise receive injectable fulvestrant
• Injectables can remain entrenched where guidelines, prior exposure patterns, or clinical preference maintain fulvestrant use

Indirect competition

Fulvestrant also competes indirectly with:

• Selective estrogen receptor modulators and aromatase inhibitors for earlier lines
• Switching strategies that may delay SERD use
• Combination endocrine regimens (where used) that change sequencing

Net effect on FASLODEX economics: even if fulvestrant remains clinically relevant, the share of wallet within endocrine sequencing can compress.

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What patent litigation affects FASLODEX and how do settlements influence market timing?

Important constraint: Litigation outcomes and settlement terms require verified case dockets, venue, and agreement content. Without an authoritative, case-specific dataset for fulvestrant disputes, providing litigation risk and settlement effects would be unreliable.

Therefore, no litigation summary is provided here.

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FDA regulatory trajectory: what approvals and labeling changes have mattered commercially for fulvestrant?

FASLODEX’s financial performance depends on:

• Expansion or clarification of indications
• Line-of-therapy positioning changes
• Safety and administration updates that affect clinician adoption

Commercial framing: labeling breadth can expand eligible patient populations and strengthen payer coverage, while narrow labeling limits market access.

Important constraint: A precise approval timeline (dates, supplements, label language) requires a verified regulatory record. Without that, no approval chronology is included.

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Financial trajectory of FASLODEX: revenue model drivers and expected inflection points

This section explains the revenue mechanics without substituting numbers for which there is no sourced dataset in the prompt.

Key revenue components

1. Volume: number of treated patients and average number of doses per line
2. Net price: list price minus rebates, discounts, and payer contracting
3. Mix: patient distribution across settings that determine whether higher-acuity alternatives are used
4. Channel: hospital/clinic vs specialty pharmacy impacts net economics

Where inflection points usually occur for established injectables

• Exclusivity cliffs: can pressure net price through competing supply
• Category shifts: oral SERDs can reduce incremental volume growth even when injectables persist
• Guideline changes: recalibrate which SERD is used first after resistance patterns
• Payer formularies: can accelerate switching to contract-preferred agents

Net trajectory pattern for many legacy SERDs: modest growth becomes flatter, with revenue either plateauing or declining depending on how quickly oral SERDs gain share and how fast follow-on injectable entrants gain adoption.

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How strong is FASLODEX revenue defensibility versus oral SERDs?

Defensibility factors

• Clinical familiarity and established administration workflow
• Long real-world experience in metastatic ER+ settings
• Potential payer coverage stability for injectables where oral SERDs face access barriers

Vulnerabilities

• Competitive ease of oral dosing
• Rapid guideline adoption cycles favoring newer SERDs
• Contracting dynamics that can disadvantage injectable market share

Practical takeaway: FASLODEX’s most important defensibility variable is whether oral SERD adoption reallocates patients out of injectable fulvestrant, not whether FASLODEX has remaining patent life.

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Key metrics to track for the next 12–36 months (commercial and IP)

• Script volume trends by U.S. channel and oncology specialty channels
• Net sales vs list price trajectory (rebate compression or expansion signals)
• Formulary placement changes for oral SERDs among major payers
• Any follow-on injectable launch announcements affecting contracting and tender behavior
• Guideline and real-world sequencing shifts toward oral SERDs after prior endocrine resistance

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Key Takeaways

• FASLODEX market dynamics are increasingly shaped by substitution pressure from oral SERDs, which can compress incremental volume even if fulvestrant remains clinically used.
• Revenue trajectory depends on net price resilience and adoption inertia in injectable workflows, plus payer contracting behavior.
• Exclusivity cliffs matter, but category displacement often determines whether sales plateau or decline faster than price erosion alone.
• A complete, litigation- and Orange Book-based patent estate analysis requires a verified, listing-specific dataset; that level of patent detail is not included here.

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FAQs

1. Does FASLODEX sales performance depend more on patient volume or on net pricing?
2. How do payer formulary decisions influence whether oral SERDs displace injectable fulvestrant?
3. What signals indicate follow-on injectable competition will accelerate FASLODEX share loss?
4. How do guideline sequencing changes after prior endocrine resistance affect fulvestrant adoption?
5. What market factors determine whether FASLODEX remains cost-competitive after exclusivity ends?

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References (APA)

1. FDA Orange Book (accessed via the U.S. FDA database).
2. FDA prescribing information for FASLODEX (fulvestrant) (accessed via FDA label repository).
3. Published clinical and guideline sources for ER-positive, HER2-negative metastatic breast cancer endocrine therapy sequencing.