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Fulvestrant

  • Hormone
  • Given by a clinician
  • Identity checked
  • Sources last checked 2026-09-04

This page shows what was measured, who it was measured in, and what that does not settle.

What Fulvestrant does in the body

Monotherapy Fulvestrant injection is indicated for the treatment of: Hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer in postmenopausal women not previously treated with endocrine therapy, or HR-positive advanced breast cancer in postmenopausal women with disease progression following endocrine therapy.

From the FDA-approved label: Many breast cancers have estrogen receptors (ER) and the growth of these tumors can be stimulated by estrogen. Fulvestrant is an estrogen receptor antagonist that binds to the estrogen receptor in a competitive manner with affinity comparable to that of estradiol and downregulates the ER protein in human breast cancer cells. In vitro studies demonstrated that fulvestrant is a reversible inhibitor of the growth of tamoxifen-resistant, as well as estrogen-sensitive human breast cancer (MCF-7) cell lines. In in vivo tumor studies, fulvestrant delayed the establishment of tumors from xenografts of human breast cancer MCF-7 cells in nude mice.

Why people take it. Monotherapy Fulvestrant injection is indicated for the treatment of: Hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer in postmenopausal women not previously treated with endocrine therapy, or HR-positive advanced breast cancer in postmenopausal women with disease progression following endocrine therapy.

What happened in people

RNAWiki has not yet published a reviewed conclusion for this use.

A fixed RNAWiki sentence

Where this came from

Wording RNAWiki always uses, not a finding about this substance.

No reviewed claim names a result for any goal on this record.

No source is stored against this line.

The limit that matters most

Not recorded.

Where it acts
Not recorded.
Kind of result
No result is published, so no kind of result applies yet
Supervision
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.

What the registries record it as

  • The substance registry classes this as chemical.

    FDA substance registry · 22X328QOC4 · read 2026-08-29

  • Its recorded molecular formula is C32H47F5O3S, weighing 606.77.

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-30

Where each sentence above came from

The use the label states, quoted from it. No plain-language version of this sentence has been written.

The use the label states, quoted from it. It is written for a clinician, not for a reader without medical training.

No statement of the main limit is recorded.

The four opening statements run to 207 words.

Words this page uses

Four words worth knowing first

Chosen from what this page shows, with each one explained before the word it depends on.

Stand-in result

A stand-in result is a number measured because the real result takes too long.

A picture of it, and where the picture fails

It is like judging a journey by the speedometer rather than by arriving.

Where that stops being true. Speed does predict arrival. Many stand-in results do not predict the real one.

What people get wrong. A stand-in result is often reported as the result itself.

A surrogate endpoint substituted for a clinical endpoint, valid only where the substitution has been shown to hold.

Enzyme

An enzyme is a protein that speeds up one chemical change.

A picture of it, and where the picture fails

An enzyme is like a machine on a production line doing one cut.

Where that stops being true. A machine is switched on and off by a person. Enzymes are controlled by the cell.

What people get wrong. Enzymes are thought to be used up. They are not; they work again and again.

A catalytic protein that lowers the activation energy of a specific reaction.

Receptor

A receptor is a part of a cell that a signal fits into.

A picture of it, and where the picture fails

A receptor is like a lock waiting for one key.

Where that stops being true. A lock either opens or does not. A receptor can be half-triggered, or worn out.

What people get wrong. Fitting a receptor is read as causing a benefit. It causes a step, and nothing more.

A protein that binds a specific ligand and converts that binding into a cellular response.

Pathway

A pathway is a chain of steps inside a cell, each one setting off the next.

A picture of it, and where the picture fails

A pathway is like a row of dominoes.

Where that stops being true. Dominoes fall one way. Pathways loop back and can switch themselves off.

What people get wrong. Changing one step is read as changing the outcome. Other steps often absorb it.

An ordered series of molecular interactions producing a defined cellular change.

What happened in peopleRead from sources, not yet reviewed

What happened in people

Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.

Steady state plasma trough concentrations of tamoxifen, desmethyltamoxifen and anastrozole

The study did not show it

Who was studied
NCT00784862
How many people
9358
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intramuscular

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Accrual of patients to ComboMATCH treatment trials

The study did not show it

Who was studied
NCT05564377
How many people
2900
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intramuscular

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

3-year invasive disease-free survival

The study did not show it

Who was studied
NCT07581834
How many people
2000
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intramuscular

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Rate of endocrine resistant disease-(First Phase)

The study did not show it

Who was studied
NCT01953588
How many people
1473
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intramuscular

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Progression Free Survival (PFS)

The study did not show it

Who was studied
NCT06757634
How many people
1180
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intramuscular

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

invasive Disease-free Survival (iDFS)

The study did not show it

Who was studied
NCT06341894
How many people
1163
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intramuscular

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
What we know
RNAWiki holds 6 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.

What happened in peopleRead from sources, not yet reviewed

How close this is to real life

The top step is something a person would feel or care about. The bottom is a guess from software. Filled steps are where evidence exists for this substance.

  1. Living longer, or avoiding a major event Evidence recorded. Death, a heart attack, a stroke, a hospital stay.9 registered measures of this kind. 3 written-up studies measured this and did not show a benefit.
  2. What a body can do day to day No evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
  3. Measured performance No evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
  4. Symptoms and quality of life No evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.No registered study measures this.
  5. A number that stands in for health Evidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.4 registered measures of this kind.
  6. A step measured inside a person Evidence recorded. Something measured in human tissue or human cells.1 registered measure inside human tissue.
  7. Animals Evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in Mouse. A result in animals says what to test next. It does not say what happens in people.
  8. Cells in a dish Evidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
  9. A guess from software No evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.

Higher on these steps means closer to something a person would feel. It does not mean better done.

What it would be like to takeRead from sources, not yet reviewed

Felt, measured, or meaningful

Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.

Felt

Things a person could notice without a test.

No registered study measured anything of this kind.

Measured

Things only a test, a scale or a device shows.

  • pfs in hemoglobin a1c less than 5 7 at baseline
  • ki 67 levels from baseline to day 28 biopsy samples
  • phase i maximum observed plasma concentration of gdc 0032
  • sitting diastolic blood pressure
  • sitting systolic blood pressure

Meaningful

Things that change how a life goes, not only a number.

  • time to disease progression
  • progression free survival
  • disease free survival events
  • progression free survival at 4 months
  • overall survival
  • event free survival
  • disease progression or death
  • progression free survival at 12 months
  • progression free survival at 6 months

A registered study says what someone planned to measure. It does not say what they found. A number moving is not the same as a life going better. The two are shown apart here.

Felt, but not shown to help. A person notices a change. No study showed it leads anywhere good.

Measured, but not felt. A number moves. The person notices nothing. Both can be true.

Measured, but not shown to matter. A number moves in the good direction. Nobody showed that lives went better.

Matters, but takes years. The result that counts may take longer than anyone would keep watching.

Names that fit none of the three (26)
  • objective response rate
  • clinical benefit rate
  • time to tumor progression
  • time to progression
  • objective tumor response
  • objective response
  • clinical tumor response as assessed by recist criteria
  • objective response rate determined by clinical palpation
  • phase i maximum tolerated dose for dose level 1
  • response
  • pathologic complete response rate
  • safety and tolerability in terms of number of adverse events
  • incidence rate of dose limiting toxicities
  • phase i auc from zero to tau of gdc 0032
  • phase i time to reach cmax of gdc 0032
  • phase i terminal half life of gdc 0032
  • bor in cohort t and t2
  • clinically significant effects
  • adverse events
  • bone scan response rate

These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.

What it would be like to takeRead from sources, not yet reviewed

How long anything takes

Nine different lengths of time that get confused with each other. None of them is worked out from another.

  1. Before anything is noticed. RNAWiki does not store this separately, and never works it out from another figure on this page.

  2. Before a test result moves. RNAWiki does not store this separately, and never works it out from another figure on this page.

  3. Before performance moves. RNAWiki does not store this separately, and never works it out from another figure on this page.

  4. How long the result was watched. No finished study window is recorded for a study that tested this substance.

  5. How long people took it. How long people actually took it is not stored. The study window is not the same thing.

  6. How long people were followed. Follow-up length is not stored separately. It is never read off the study window, which would be a different thing.

  7. How fast the body clears it. 40 days

    Read from the label, which states: “After an intramuscular injection of 250 mg, the clearance (Mean ± SD) was 690 ± 226 mL/min with an apparent half-life about 40 days.”

  8. How long effects linger. RNAWiki does not store this separately, and never works it out from another figure on this page.

  9. Beyond the studies. Nothing is recorded about the long term.

    The longest finished study sets the edge of what anyone measured.

A study window is not how long people took it, and neither is how long they were followed. Where RNAWiki holds only one of the three, it shows one.

What is missing or unclearRead from sources, not yet reviewed

Were people like you studied?

RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.

Who was studied

People similar to this profile were included.

  • Monotherapy Fulvestrant injection is indicated for the treatment of: Hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer in postmenopausal women not previously treated with endocrine therapy, or HR-positive advanced breast cancer in postmenopausal women with disease progression following endocrine therapy.

Who is missing from the studies

  • Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

What the label states about particular groups

  • On pediatric, the label states: “Safety and effectiveness in pediatric patients have not been established.”

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-30

  • On older people, the label states: “For Fulvestrant injection 250 mg, when tumor response was considered by age, objective responses were seen in 22% and 24% of patients under 65 years of age and in 11% and 16% of patients 65 years of age and older, who were treated with Fulvestrant injection in Study 0021 and Study 0020, respectively.”

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-30

  • On people who are pregnant, the label states: “Risk Summary Based on findings from animal studies and its mechanism of action, Fulvestrant injection can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1) ] .”

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-30

  • On people who are breastfeeding, the label states: “Risk Summary There is no information regarding the presence of fulvestrant in human milk, nor of its effects on milk production or breastfed infant.”

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-30

  • On people with reduced liver function, the label states: “The pharmacokinetics of fulvestrant were evaluated after a single dose of 100 mg in subjects with mild and moderate hepatic impairment and normal hepatic function (n = 7 subjects/group), using a shorter-acting intramuscular injection formulation.”

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-30

  • On people with reduced kidney function, the label states: “Negligible amounts of fulvestrant are eliminated in urine; therefore, a study in patients with renal impairment was not conducted.”

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-30

Where the result stopped carrying

  • This is a scope explorer, not a diagnosis engine.
  • It shows who was studied so you can see whether people similar to you were included.

RNAWiki cannot tell whether a study fits you. It can show who was in it.

What it would be like to takeRead from sources, not yet reviewed

Why it might seem to do nothing

A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.

It was studied for a different goal

The studies measured something else entirely.

On this record: Some registered studies measured things that match no goal on this page.

It was studied in different people

The people in the studies were not much like the reader.

On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

The evidence may simply be wrong

Small early studies often do not hold up.

On this record: RNAWiki has not yet published a reviewed conclusion for this use.

Other reasons RNAWiki checked and found nothing for (10)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.

None of these is a reason to take more. Taking more is not a step this page ever suggests.

What it would be like to takeRead from sources, not yet reviewed

What taking it involves

The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.

How it is supplied

Given by a clinician

Quoted from a source

Where this came from

Copied from a source RNAWiki stored, with the source named.

Read from the recorded approval status.

No source is stored against this line.

Form and route

Intramuscular

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

The form and route recorded on this substance.

No source is stored against this line.

Who oversees it

Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.

Quoted from a source

Where this came from

Copied from a source RNAWiki stored, with the source named.

Suppression classes recorded: S3.

No source is stored against this line.

What is in the pack

Sold as solution, injection, injection, solution, given by the intramuscular, intravenous route.

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

Recorded notes on how this is sold and what that means for what is in the pack.

No source is stored against this line.

Where it is registered

Regulatory records are listed in the technical disclosure at the foot of this page.

Counted from records

Where this came from

A count of rows RNAWiki holds. It describes our records, not your body.

Register entries are stored per jurisdiction and shown with their dates.

No source is stored against this line.

Why people stop

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

No record of why people stopped taking it is stored for this substance.

No source is stored against this line.

What it would be like to takeNothing found in the sources checked

What can go wrong

Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.

Nothing found in the sources checked

No harm is recorded against this substance in the sources RNAWiki checked. Finding nothing is not the same as showing there is nothing.

The sources listed were searched and held nothing. That is not the same as nothing existing.

Reports sent to a regulator

  • These are reports people sent to a regulator. They do not show the medicine caused the reaction.
  • Nobody counted how many people took the medicine and reported nothing.
  • The same event can be reported more than once, and many reports are incomplete.
  • News coverage, lawsuits and new warnings change how often people report.
  • A count is not a rate and not a risk.

Fulvestrant appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 4796 reaction mentions were counted. One report can name several reactions.

The recorded terms (10)
  • malignant neoplasm progression — 1201 reaction mentions
  • metastases to bone — 571 reaction mentions
  • neutropenia — 508 reaction mentions
  • fatigue — 505 reaction mentions
  • metastases to liver — 464 reaction mentions
  • breast cancer metastatic — 399 reaction mentions
  • neoplasm progression — 359 reaction mentions
  • disease progression — 300 reaction mentions
  • breast cancer — 296 reaction mentions
  • thrombocytopenia — 193 reaction mentions
  • open-targets-adr · recorded 2026-06-24 · a recorded source, not a stored snapshot

Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.

Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

What is missing or unclearRead from sources, not yet reviewed

Does the exact form matter?

Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.

The form that was studied

Intramuscular

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

The form used in the studies cited on this page.

No source is stored against this line.

What is sold

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

Nothing further is recorded about which forms are sold.

No source is stored against this line.

What is recorded as being sold

  • 39 products list this as an active ingredient in the United States drug directory. 39 of them contain it and nothing else.

    FDA National Drug Code directory · 83831-159 · read 2026-08-29

  • They are sold as injection, injection, solution and powder, taken intramuscular and intravenous.

    FDA National Drug Code directory · 83831-159 · read 2026-08-29

  • The regulator's established pharmacologic class for it is estrogen receptor antagonist [epc], estrogen receptor antagonists [moa] and selective estrogen receptor modulators [moa].

    FDA National Drug Code directory · 83831-159 · read 2026-08-29

  • 26 published labels name it as an active ingredient. 26 of them describe this substance alone, which is where its own label text on this page comes from.

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-29

  • Those labels are classed as human prescription drug.

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-29

  • FULVESTRANT is intramuscular at 3 DOSAGE FORMS AND STRENGTHS Fulvestrant injection, an injection for intramuscular administration, is supplied as 5 mL single-dose prefilled syringes containing 250 mg/5 mL fulvestrant., recorded as fda label in effect 2022-07-26 in the United States.

    US prescribing information · 477098a1-cd37-48ad-b17f-aef610cb0f57 · read 2026-08-30

Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.

What it would be like to takeRead from sources, not yet reviewed

What you could measure

This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.

Self-experiment planning is not offered for a prescription or clinician-supervised medicine. The questions below are for a clinician or pharmacist.

Questions worth asking

  • Which of the trials of Fulvestrant studied people like me?
  • What was measured, and for how long?
  • Was the result a laboratory value or a health outcome?
  • What would we watch for, and when would we stop?

Tracking can show whether something changed for you. It cannot show what caused it.

RNAWiki records evidence. It does not say whether this substance is right for you.

What is missing or unclearRead from sources, not yet reviewed

What nobody knows yet

Open questions, each with why it is open and what would close it.

Missing populations

Which groups were under-represented in the studies has not been recorded.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing long-term data

No completed tested study window is recorded.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

No reviewed conclusion

RNAWiki has not yet published a reviewed conclusion for this use.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing interaction studies

No interaction was found in the registers checked. Not finding one is not the same as showing there is none.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Formulation uncertainty

Several salts, forms or products of Fulvestrant are recorded. Results from one form may not transfer to another.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Mechanism not reviewed

No reviewed mechanism story exists for this substance.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

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Check any of this yourself

Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.

How many documents were read

  • 25 documents were read for this substance.

    RNAWiki source record

  • 25 of them state the same halfLife, and they agree.

    RNAWiki source record

Where else this substance is registered

FDA substance identifier (UNII)
22X328QOC4
RxNorm concept
727762

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How this medicine reached us

Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.

What the approval register records

  • 18 approved applications cover products containing this substance. The earliest was NDA021344, approved 20020425 to ASTRAZENECA.

    Drugs@FDA application register · NDA021344 · read 2026-08-29

  • Marketing status on the register: discontinued and prescription.

    Drugs@FDA application register · NDA021344 · read 2026-08-29

  • The earliest marketing start date recorded for a listed product is 20060612.

    FDA National Drug Code directory · 83831-159 · read 2026-08-29

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6 questions this page could not answer

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Recorded evidence blocks (13)

What did Fulvestrant's largest trial (95637 people) and its longest (23 years) measure?


95637 people in Fulvestrant's largest registered study, 23 years in its longest registered window, measuring Mean Baseline GH Concentration. ClinicalTrials.gov · 2026-09-01

238 phase2, 131 phase1, 69 phase3, 17 na or unstated, 7 phase4, 4 na, 2 early phase1; NCT00585507; 2027-03-15; no ageing endpoint recorded. Last human test completed 2026, NCT04572295.

Interpretation These counts include studies where Fulvestrant was a comparison treatment, a background treatment or an exposure in an observational study, and the longest window may be a planned end date. Trial roles have not yet been classified for this record.

Show the evidence
  • phase2
    238
  • phase1
    131
  • phase3
    69
  • na or unstated
    17
  • phase4
    7
  • na
    4
2 more recorded rows
  • early phase1
    2
  • Last recorded human test NCT04572295
    2026-06-18

recorded 2026-09-01 · last checked 2026-09-04

From mouse to human: where has Fulvestrant shown biomarker?


mouse: mechanism-only and human: biomarker (417): the rungs where Fulvestrant has a recorded finding. Europe PMC and ClinicalTrials.gov · organism ladder · 2026-09-01

Interpretation Mean Baseline GH Concentration — the recorded outcome words.

Yeast C. elegans Drosophila Mouse mechanism-onlyRat Dog Non-human primate Human biomarker
Show the evidence
  • mouse
    mechanism-only
  • human NCT01186796
    biomarker; Mean Baseline GH Concentration; 417

recorded 2026-09-01 · last checked 2026-09-04

71 of Fulvestrant's trials stopped: safety, futility/efficacy, accrual/recruitment, funding/business, sponsor decision unspecified, other?


safety (14), futility/efficacy (2), accrual/recruitment (23), funding/business (13), sponsor decision unspecified (1) and other (18): Fulvestrant's stop wording, clustered. ClinicalTrials.gov · 2026-09-01

"low accrual"; 71 of 417 registered studies

Show the evidence

Trial

  • NCT00010153
    terminated; "low accrual"
  • NCT00138125
    terminated; "Due to low accrual"
  • NCT00183963
    terminated; "Insufficient accrual"
  • NCT00217464
    terminated; "Closed for futility"
  • NCT00372996
    terminated; "This study was closed to enrollment as of 13 May 2011 due to business reasons. Premature closure was not prompted by any safety or efficacy concerns."
  • NCT00543127
    terminated; "Unjustified decision of company that funded the trial."
14 further recorded trials
  • NCT00570258
    terminated; "FDA approved higher dose of study drug. Dose used in protocol lower than SOC - enrollment stopped, those on treatment were given option to opt out."
  • NCT00722072
    terminated; "Sponsor pulled funding and low accrual"
  • NCT00774878
    terminated; "Company decision to discontinue the AVE1642 development program, not due to any safety or efficacy concerns"
  • NCT00903006
    terminated; "Low Accrual"
  • NCT00932152
    terminated; "Poor enrollment/suspended to accrual; will close per AstraZeneca request"
  • NCT01004419
    withdrawn; "Support for investigational products has been withdrawn."
  • NCT01296555
    terminated; "The Sponsor discontinued the manufacturing and development of taselisib due to modest clinical benefit and limited tolerability."
  • NCT01528345
    terminated; "Slow and low enrollment"
  • NCT01633060
    terminated; "Novartis decided not to pursue further development of buparlisib program (assessment of moderate PFS benefit with know, but manageable, buparlisib profile)."
  • NCT01953926
    terminated; "The study was terminated to align with the sponsor's current development plans for neratinib. The decision was not based on any new efficacy or safety data for neratinib."
  • NCT02000596
    terminated; "funding withdrawn by sponsor"
  • NCT02115594
    withdrawn; "Internal decision"
  • NCT02137837
    terminated; "lack of accrual"
  • NCT02140437
    withdrawn; "The progress of enrollment is too slow."

recorded 2026-09-01 · last checked 2026-09-04

Human studies of Fulvestrant used faslodex 500mg — over how long?


studies of Fulvestrant used the recorded amount. ClinicalTrials.gov · 2026-09-01

7 recorded entries; human; also "faslodex 500mg", "fulvestrant 500 mg", "Fulvestrant 500 mg"

Show the evidence

human

  • NCT01602380
    faslodex 500mg
  • NCT02345772
    fulvestrant 500 mg
  • NCT02646735
    Fulvestrant 500 mg
  • NCT03024580
    Fulvestrant 50Mg Solution for Injection
  • NCT03447132
    Fulvestrant 500mg
  • NCT03620643
    Fulvestrant 50 MG/ML Prefilled Syringe [Faslodex or generic]
1 more recorded row
  • human NCT04920708
    Fulvestrant 500g

recorded 2026-09-01 · last checked 2026-09-04

Fulvestrant's half-life is 40 days — which schedules were studied?


40 days, the half-life Fulvestrant's label states. openfda-label · e20d8ca3-8837-4003-8b01-1ebec342062a · 2026-08-30

Show the evidence
  • half life
    40 days; After an intramuscular injection of 250 mg, the clearance (Mean ± SD) was 690 ± 226 mL/min with an apparent half-life about 40 days.
  • metabolism
    Metabolism: Biotransformation and disposition of fulvestrant in humans have been determined following intramuscular and intravenous administration of 14 C-labeled fulvestrant.

recorded 2026-08-30 · last checked 2026-09-04

Which of adverse events, bone scan response rate and bor in cohort t and t2 did Fulvestrant's trials measure?


adverse events, bone scan response rate and bor in cohort t and t2 lead 40 outcome terms across Fulvestrant's trials. ClinicalTrials.gov · 2026-09-01

time to tumor progression, time to progression, objective tumor response, progression free survival, objective response and pfs in hemoglobin a1c less than 5 7 at baseline follow.

Show the evidence
  • objective response rate
    1
  • clinical benefit rate
    1
  • time to disease progression
    1
  • time to tumor progression
    1
  • time to progression
    1
  • objective tumor response
    1
14 more recorded rows
  • progression free survival
    1
  • objective response
    1
  • pfs in hemoglobin a1c less than 5 7 at baseline
    1
  • disease free survival events
    1
  • ki 67 levels from baseline to day 28 biopsy samples
    1
  • clinical tumor response as assessed by recist criteria
    1
  • progression free survival at 4 months
    1
  • overall survival
    1
  • event free survival
    1
  • disease progression or death
    1
  • objective response rate determined by clinical palpation
    1
  • phase i maximum tolerated dose for dose level 1
    1
  • response
    1
  • pathologic complete response rate
    1

recorded 2026-09-01 · last checked 2026-09-04

Which of Fulvestrant's 147 ongoing trials reports first?


147 registered trials of Fulvestrant are open; earliest completion 2025-12. ClinicalTrials.gov · 2026-09-01

Time to Progression (TTP); To assess the clinical benefit rate for subjects receiving this dose and schedule of fulvestrant.; latest 2033-05

Show the evidence

Trial

  • NCT00099437
    "Comparison of Fulvestrant (FASLODEX™) 250 mg and 500 mg in Postmenopausal Women With Oestrogen Receptor Positive Advanced Breast Cancer Progressing or Relapsing After Previous Endocrine Therapy."; n 736; "Time to Progression (TTP)"; 2026-12-31
  • NCT00585507
    "Efficacy and Safety of 500mg of Fulvestrant"; n 40; "To assess the clinical benefit rate for subjects receiving this dose and schedule of fulvestrant."; 2027-03-15
  • NCT01953588
    "Fulvestrant and/or Anastrozole in Treating Postmenopausal Patients With Stage II-III Breast Cancer Undergoing Surgery"; n 1473; "Rate of endocrine resistant disease-(First Phase)"; 2027-04-01
  • NCT01992952
    "Fulvestrant +/- Akt Inhibition in Advanced Aromatase Inhibitor Resistant Breast Cancer"; n 149; "Phase 1b primary outcome measure: Maximum Tolerated Dose of AZD5363 in combination with fulvestrant"; 2025-12-31
  • NCT02057133
    "A Study of LY2835219 (Abemaciclib) in Combination With Therapies for Breast Cancer That Has Spread"; n 198; "Number of Participants with One or More Drug-Related Adverse Events"; 2026-12
  • NCT02107703
    "A Study of Abemaciclib (LY2835219) Combined With Fulvestrant in Women With Hormone Receptor Positive HER2 Negative Breast Cancer"; n 669; "Progression-Free Survival (PFS)"; 2027-12
14 further recorded trials
  • NCT02476786
    "Endocrine Treatment Alone for Elderly Patients With Estrogen Receptor Positive Operable Breast Cancer and Low Recurrence Score"; n 50; "Response rate"; 2032-07-31
  • NCT02738866
    "Palbociclib With Fulvestrant for Metastatic Breast Cancer After Treatment With Palbociclib and an Aromatase Inhibitor"; n 60; "Progression-free survival"; 2026-12
  • NCT02763566
    "A Study of Abemaciclib (LY2835219) in Participants With Breast Cancer"; n 463; "Progression Free Survival (PFS) (Abemaciclib + NSAI & Placebo NSAI)"; 2028-03
  • NCT02778685
    "Pembrolizumab, Endocrine Therapy, and Palbociclib in Treating Postmenopausal Patients With Newly Diagnosed Metastatic Stage IV Estrogen Receptor Positive Breast Cancer"; n 47; "Response Rate (Complete Response or Partial Response)"; 2026-03-30
  • NCT02947685
    "Randomized, Open Label, Clinical Study of the Targeted Therapy, Palbociclib, to Treat Metastatic Breast Cancer"; n 518; "Progression-free Survival (PFS) as Assessed by Investigator"; 2026-07-31
  • NCT02955394
    "Preoperative Fulvestrant With or Without Enzalutamide in ER+/Her2- Breast Cancer"; n 61; "Number of Patients With a PEPI Score Equal to Zero at Post Treatment"; 2027-02
  • NCT03006172
    "To Evaluate the Safety, Tolerability, and Pharmacokinetics of Inavolisib Single Agent in Participants With Solid Tumors and in Combination With Endocrine and Targeted Therapies in Participants With Breast Cancer"; n 200; "Stage 1: Percentage of Participants With Dose Limiting Toxicities"; 2026-12-31
  • NCT03147287
    "Palbociclib After CDK and Endocrine Therapy (PACE)"; n 220; "Progression-Free Survival (PFS), According to RECIST v1.1 Criteria (Investigator Assessment)"; 2026-06-30
  • NCT03393845
    "Study of Pembrolizumab Plus Fulvestrant in Hormone Receptor Positive, HER-2 Negative Advanced/Metastatic Breast Cancer Patients"; n 47; "Clinical Benefit Ratio (CBR)"; 2027-09-01
  • NCT03424005
    "A Study Evaluating the Efficacy and Safety of Multiple Treatment Combinations in Patients With Metastatic or Locally Advanced Breast Cancer"; n 1132; "Objective Response Rate (ORR)"; 2030-09-30
  • NCT03425838
    "Endocrine Therapy Plus CDK4/6 in First or Second Line for Hormone (SONIA) Receptor Positive Advanced Breast Cancer"; n 1050; "PFS2"; 2028-12
  • NCT03531645
    "Fulvestrant Plus Abemaciclib in Women With Advanced Low Grade Serous Carcinoma"; n 18; "Clinical Benefit Rate (CBR)"; 2027-09-30
  • NCT03939897
    "Testing the Addition of Copanlisib to Usual Treatment (Fulvestrant and Abemaciclib) in Metastatic Breast Cancer"; n 24; "Dose-limiting Toxicity (DLT)"; 2027-07-31
  • NCT03959891
    "AKT Inhibitor, Ipatasertib, With Endocrine and CDK 4/6 Inhibitor for Patients With Metastatic Breast Cancer (TAKTIC)"; n 77; "Incidence of Treatment-Emergent Adverse Events"; 2027-08

recorded 2026-09-01 · last checked 2026-09-04

Which running trial of Fulvestrant could settle lifespan?


NCT05536128 measures 6-month progression-free survival (PFS) rate, reading out 2025-12-31.

46 open trials; n 64; "Evaluating the Efficacy and Safety of Fulvestrant Plus DNA Damage Repair Inhibitors After a CDK4/6 Inhibitor"

Show the evidence

Trial

  • NCT05536128
    "Evaluating the Efficacy and Safety of Fulvestrant Plus DNA Damage Repair Inhibitors After a CDK4/6 Inhibitor"; n 64; "6-month progression-free survival (PFS) rate"; 2025-12-31
  • NCT04762979
    "Alpelisib (BYL719) in Combination With Continued Endocrine Therapy Following Progression on Endocrine Therapy in Hormone Receptor Positive, HER2 Negative, PIK3CA Mutant Metastatic Breast Cancer"; n 44; "Progression-Free Survival (PFS)"; 2026-05
  • NCT05063786
    "Trastuzumab + Alpelisib +/- Fulvestrant vs Trastuzumab + CT in Patients With PIK3CA Mutated Previously Treated HER2+ Advanced BrEasT Cancer (ALPHABET)"; n 27; "Progression Free Survival (PFS)"; 2026-06
  • NCT05365178
    "To Evaluate the Efficacy and Safety of TQB3616 in Combination With Fulvestrant Versus Placebo in Combination With Fulvestrant in Previously Untreated Hormone-receptor (HR)-Positive, Human Epidermal Growth Factor Receptor 2 (HER2)-Negative Advanced Breast Cancer"; n 432; "Progression-free survival as assessed by the investigator"; 2026-06
  • NCT04305496
    "Capivasertib+Fulvestrant vs Placebo+Fulvestrant as Treatment for Locally Advanced (Inoperable) or Metastatic HR+/HER2- Breast Cancer"; n 818; "Progression Free Survival: Overall Population (Months) in the Global Cohort"; 2026-06-22
  • NCT03147287
    "Palbociclib After CDK and Endocrine Therapy (PACE)"; n 220; "Progression-Free Survival (PFS), According to RECIST v1.1 Criteria (Investigator Assessment)"; 2026-06-30
14 further recorded trials
  • NCT02947685
    "Randomized, Open Label, Clinical Study of the Targeted Therapy, Palbociclib, to Treat Metastatic Breast Cancer"; n 518; "Progression-free Survival (PFS) as Assessed by Investigator"; 2026-07-31
  • NCT05890287
    "A Study of Chidamide Plus Endocrine in Maintenance Treatment of HR+/HER2- Breast Cancer After First-line Chemotherapy"; n 60; "Progression-free survival"; 2026-10-01
  • NCT05306340
    "A Study Evaluating the Efficacy and Safety of Giredestrant Plus Everolimus Compared With the Physician's Choice of Endocrine Therapy Plus Everolimus in Participants With Estrogen Receptor-Positive, HER2-Negative, Locally Advanced or Metastatic Breast Cancer (evERA Breast Cancer)"; n 373; "Progression-Free Survival, as Determined by the Investigator According to RECIST v1.1, in the ESR1m Subpopulation and ITT Population"; 2026-10-15
  • NCT02738866
    "Palbociclib With Fulvestrant for Metastatic Breast Cancer After Treatment With Palbociclib and an Aromatase Inhibitor"; n 60; "Progression-free survival"; 2026-12
  • NCT04650581
    "Fulvestrant and Ipatasertib for Advanced HER-2 Negative and Estrogen Receptor Positive (ER+) Breast Cancer Following Progression on First Line CDK 4/6 Inhibitor and Aromatase Inhibitor"; n 250; "Number of Participants With Progression-free Survival (PFS) Using RECIST 1.1"; 2026-12-31
  • NCT05501886
    "Gedatolisib Plus Fulvestrant With or Without Palbociclib vs Standard-of-Care for the Treatment of Patients With Advanced or Metastatic HR+/HER2- Breast Cancer (VIKTORIA-1)"; n 701; "Progression Free Survival (PFS) in Patients with PIK3CA WT and PIK3CA MT Breast Cancer"; 2026-12-31
  • NCT04544189
    "Study Assessing the Efficacy and Safety of Treatment With Alpelisib Plus Fulvestrant Versus Placebo Plus Fulvestrant in Chinese Men and Postmenopausal Women With Advanced Breast Cancer"; n 69; "Progression Free Survival (PFS)"; 2027-01-29
  • NCT05720260
    "Immunotherapy, Hormone Therapy, and AKT Inhibitor for Premenopausal ER Positive MBC"; n 42; "Progression-free survival"; 2027-01-31
  • NCT05038735
    "Study to Assess the Efficacy and Safety of Alpelisib Plus Fulvestrant in Participants With HR-positive (HR+), HER2-negative, Advanced Breast Cancer After Treatment With a CDK4/6 Inhibitor and an Aromatase Inhibitor."; n 210; "Progression-free survival (PFS) based on BIRC assessments and using RECIST v1.1 criteria"; 2027-02-26
  • NCT04920708
    "Fulvestrant, Ipatasertib and CDK4/6 Inhibition in Metastatic ER+/HER2- Breast Cancer Patients Without ctDNA Suppression"; n 57; "Assess progression free survival (PFS)"; 2027-06
  • NCT04214288
    "A Study to Investigate Efficacy and Safety With Oral AZD9833 Compared With Intramuscular Fulvestrant in Post-menopausal Women at Least 18 Years of Age With Advanced ER-positive HER2 Negative Breast Cancer"; n 240; "Progression-free Survival (PFS)"; 2027-06-16
  • NCT04053322
    "Durvalumab, With Olaparib and Fulvestrant in Advanced ER+, HER2- Breast Cancer Patients."; n 172; "Progression-free survival rate (PFSR)"; 2027-08
  • NCT04975308
    "A Study of Imlunestrant, Investigator's Choice of Endocrine Therapy, and Imlunestrant Plus Abemaciclib in Participants With ER+, HER2- Advanced Breast Cancer"; n 874; "Investigator-assessed Progression Free Survival (PFS) (Between Arm A and Arm B)"; 2027-08
  • NCT05181033
    "Lenvatinib+Letrozole Versus Fulvestrant in Metastatic ER+/HER2- Breast Cancer, Post Progression on Al + CDK4/6 Inhibitor"; n 120; "Progression-free survival (PFS) of patients treated on lenvatinib and letrozole compared to single agent fulvestrant"; 2027-08

Which 52 trials of Fulvestrant posted no result?


Posted no result
52 of 52 completed trials
Registrations
NCT00635713, NCT00417430, NCT00093002, NCT00146601, NCT00327769 and NCT00012025, and 46 more
Completion dates
oldest 2004-09; newest 2024-09-02
Show the evidence

Trial

  • NCT00635713
    2004-09
  • NCT00417430
    2006-12
  • NCT00093002
    2007-07
  • NCT00146601
    2007-07
  • NCT00327769
    2007-09
  • NCT00012025
    2008-08
14 further recorded trials
  • NCT00660803
    2009-04
  • NCT00328120
    2010-06
  • NCT00944918
    2011-06
  • NCT01399086
    2011-09
  • NCT00241449
    2012-01
  • NCT00244998
    2012-06
  • NCT00065325
    2014-09
  • NCT02026973
    2015-11
  • NCT01437566
    2016-04
  • NCT02260661
    2016-07
  • NCT01160718
    2016-09
  • NCT01339442
    2016-12-28
  • NCT02549430
    2017-02-09
  • NCT02795039
    2017-03-03

At the median, Fulvestrant's trials enrolled 96.5 people — anything larger?


Median enrolment
96.5
Largest enrolment
95637
Registered trials counted
416

What do 4796 spontaneous reports say about Fulvestrant — and not say?


These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.

Fulvestrant appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 4796 reaction mentions were counted: malignant neoplasm progression 1201; metastases to bone 571; neutropenia 508; fatigue 505. open-targets-adr · CHEMBL1358 · 2026-06-24

Show the evidence
  • malignant neoplasm progression
    1201
  • metastases to bone
    571
  • neutropenia
    508
  • fatigue
    505
  • metastases to liver
    464
  • breast cancer metastatic
    399
4 more recorded rows
  • neoplasm progression
    359
  • disease progression
    300
  • breast cancer
    296
  • thrombocytopenia
    193

recorded 2026-06-24 · last checked 2026-09-04

Fulvestrant and CYP3A4 and CYP1A2: shared by which compounds?


CYP3A4 and CYP1A2 appear in Fulvestrant's recorded interaction sentences, 5 in all. openfda-label+europepmc · 2026-08-30

Interpretation pharmacokinetics

Show the evidence
  • CYP1A2 pharmacokinetics
    Fulvestrant does not significantly inhibit any of the major CYP isoenzymes, including CYP 1A2, 2C9, 2C19, 2D6, and 3A4 in vitro , and studies of co-administration of fulvestrant with midazolam indicate that therapeutic doses of fulvestrant have no inhibitory effects on CYP 3A4 or alter blood levels of drug metabolized by that enzyme.

CYP3A4

  • pharmacokinetics
    Studies using human liver preparations and recombinant human enzymes indicate that cytochrome P-450 3A4 (CYP 3A4) is the only P-450 isoenzyme involved in the oxidation of fulvestrant; however, the relative contribution of P-450 and non-P-450 routes in vivo is unknown.
  • pharmacokinetics
    Also, results from a healthy volunteer study with ketoconazole, a potent inhibitor of CYP 3A4, indicated that ketoconazole had no effect on the pharmacokinetics of fulvestrant and dosage adjustment is not necessary in patients co-prescribed CYP 3A4 inhibitors or inducers [ see Drug Interactions (7) ] .
  • pharmacokinetics
    Although fulvestrant is partly metabolized by CYP 3A4, a clinical study with rifampin, an inducer of CYP 3A4, showed no effect on the pharmacokinetics of fulvestrant.
  • pharmacokinetics
    Fulvestrant does not significantly inhibit any of the major CYP isoenzymes, including CYP 1A2, 2C9, 2C19, 2D6, and 3A4 in vitro , and studies of co-administration of fulvestrant with midazolam indicate that therapeutic doses of fulvestrant have no inhibitory effects on CYP 3A4 or alter blood levels of drug metabolized by that enzyme.

recorded 2026-08-30 · last checked 2026-09-04

What is recorded about Fulvestrant and mTOR?


"Gedatolisib potently targets all four class I PI3K isoforms and mTORC1 and mTORC2 to comprehensively block the PI3K/AKT/mTOR pathway and has shown compelling activity in early clinical trials with palbociclib and fulvestrant." — where Fulvestrant and mTOR appear together. Europe PMC · pathway abstract search · 2026-03-09

mTOR, NAD+, sirtuin, autophagy; PMID 41802242, 37644396, 39672084, 37575061

Show the evidence
  • mTOR PMID 41802242
    "Gedatolisib potently targets all four class I PI3K isoforms and mTORC1 and mTORC2 to comprehensively block the PI3K/AKT/mTOR pathway and has shown compelling activity in early clinical trials with palbociclib and fulvestrant."
  • NAD+
    "Combination therapy of the NAMPT Inhibitor, KPT9274 and the ERα agonist Fulvestrant (Fulv) synergistically reduced tumor burden in liver metastasis in vitro (combination index < 1 in cell viability assays) and in vivo in mouse xenograft models."

mTOR

  • PMID 37644396
    "The Medline, Embase and Cochrane Library databases were searched for randomized trials comparing CDK4/6 inhibitors, PI3K/mTOR inhibitors, or HDAC inhibitors vs. placebo with the addition of exemestane or fulvestrant as second-line treatments in patients with HR + advanced breast cancer up to December 16, 2021."
  • PMID 37644396
    "Compared with placebo plus fulvestrant, PFS was significantly improved by CDK4/6 inhibitor plus fulvestrant, mTOR inhibitor plus fulvestrant, mTOR inhibitor plus exemestane, and PI3K inhibitor plus fulvestrant, but not HDAC inhibitor plus exemestane."
  • sirtuin PMID 39672084
    "E2 inhibited the LPS-induced decrease of ER expression in LCs and also inhibited LPS-induced interstitial cell inflammation and pyroptosis, which was partially blocked by Selisistat (EX-527, SIRT1 inhibitor) or Fulvestrant (ICI 182,780, E2 non-genomic receptor inhibitors)."

autophagy

  • PMID 37575061
    "Thus, by exploiting those underlying mechanisms, new targets could be established to overcome endocrine resistance.<b>NEW & NOTEWORTHY</b> The development of resistance to hormone therapy caused by both fulvestrant and tamoxifen promotes autophagy with concomitant apoptosis evasion, rendering cells capable of surviving and growing."
  • PMID 36741704
    "Autophagy inhibition utilizing pharmacologic or genetic approaches only moderately enhanced the response to Fulvestrant + Palbociclib in ER+ MCF-7 breast tumor cells, slightly delaying proliferative recovery."

recorded 2026-03-09 · last checked 2026-09-04

Where it is registered
Identifiers, relations and other names

The exact record

ChEMBL id
CHEMBL1358
PubChem CID
104741
CAS number
129453-61-8
RxCUI
282357
InChIKey
VWUXBMIQPBEWFH-WCCTWKNTSA-N
Trade name
Faslodex, Fulvestrant mylan, Cligavyx, Faslodex / Cligavyx
Development code
ICI 182,780, ICI-182780, NSC-759879, ZD-9238, ZD9238
Also called
ai, ful, selective estrogen receptor degrader, serd, FULVESTRANT [EMA EPAR], FULVESTRANT [EP MONOGRAPH], FULVESTRANT [JAN], FULVESTRANT [MART.], FULVESTRANT [MI], FULVESTRANT [ORANGE BOOK], FULVESTRANT [USAN], FULVESTRANT [USP IMPURITY]
Sources (11)

Sources

  • ClinicalTrials.gov clinicaltrials.gov ·
  • ClinicalTrials.gov ClinicalTrials.gov API v2 snapshot 2026-09-01T09:00:05 ·
  • this record's own fields 2,3,5 ·
  • Europe PMC dose-response search ·
  • Europe PMC pathway abstract search ·
  • Europe PMC search ·
5 more sources

ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · Open Targets 26.06 — CC0 · derived from this page's own recorded fields; no external licence · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work

How these records are assembled · Which registers were checked

Index-quality checks
  • identity passed: no open identity hold
  • required summary fields resolved: 5 required field(s) not terminal: Why people use it, Best-supported result, Most important common problem, Biggest unanswered question, Human evidence
  • public claims reviewed: 0 reviewed claim(s); drafts are never rendered
  • source coverage passed: 11 source rows
  • no critical contamination: no quarantine open
  • canonical metadata passed: slug and display name present
  • no raw internal fields: enforced by the copy-contract test over the rendered page

This is a record of evidence. It is not medical advice, and it does not say this substance suits you. Nothing here says any substance on RNAWiki is appropriate for a child.