Fulvestrant vs Anastrozole for Breast Cancer

(FALCON Trial)

Not currently recruiting at 131 trial locations

Age: 18+

Sex: Female

Trial Phase: Phase 3

Sponsor: AstraZeneca

Disqualifiers: Life-threatening metastasis, Extensive hepatic, Brain involvement, Symptomatic pulmonary, Prior systemic therapy, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 24

Duration: 38 months

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines how Fulvestrant and Anastrozole affect breast cancer that has spread or advanced locally. It targets women who have not yet received hormonal treatments for their breast cancer. The trial includes two groups: one receives Fulvestrant injections and placebo pills, while the other receives Anastrozole pills and placebo injections. Eligible participants are postmenopausal women with locally advanced or metastatic breast cancer, with tumors that have hormone receptors. As a Phase 3 trial, this study represents the final step before FDA approval, offering participants an opportunity to contribute to potentially groundbreaking treatment advancements.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it does mention that you should not have had prior hormonal treatment for breast cancer. If you've had chemotherapy, the last dose must have been more than 28 days before joining the trial.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that both Fulvestrant (FASLODEX) and Anastrozole (ARIMIDEX) are generally well-tolerated by patients.

For Fulvestrant, studies have found that it helps patients live longer without their cancer worsening. Specifically, the FALCON trial demonstrated better results in this area. Another study found that combining Fulvestrant with another drug yielded positive effects, with many patients responding well to the treatment. This suggests that Fulvestrant is effective and safe for many patients.

Anastrozole also has strong safety data. Research indicates it significantly lowers the risk of breast cancer recurrence and reduces the chance of death from the disease. It has been used not only for treatment but also to prevent breast cancer in women at high risk, showing long-term benefits. This indicates it is safe for widespread use.

Both treatments have demonstrated safety in previous research, making them promising options for those considering joining a trial. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these treatments for breast cancer because they explore different mechanisms of action compared to traditional options. Fulvestrant works by degrading estrogen receptors, which can slow the growth of hormone-receptor-positive breast cancer cells. On the other hand, Anastrozole is an aromatase inhibitor, reducing estrogen levels in the body and thereby limiting fuel for cancer growth. These treatments offer alternative pathways to tackle the disease, potentially providing more tailored and effective options for patients.

What evidence suggests that this trial's treatments could be effective for breast cancer?

This trial will compare Fulvestrant with Anastrozole for treating advanced hormone receptor-positive breast cancer. Studies have shown that Fulvestrant significantly delays cancer growth or spread, improving progression-free survival. Specifically, the FALCON trial demonstrated notable improvement in this area with Fulvestrant. Meanwhile, Anastrozole has proven effective in reducing the risk of breast cancer recurrence and works as well as Tamoxifen, another common treatment for advanced breast cancer. Both treatments have a strong track record for managing breast cancer, offering hope for those considering joining this trial. ^{1 2 3 6 7}

Who Is on the Research Team?

Matthew Ellis, DM

Principal Investigator

Washington University School of Medicine, USA

Shankar S, MD

Principal Investigator

AstraZeneca

John Robertson, MD

Principal Investigator

Graduate Medicine and Health School, University of Nottingham, UK

Are You a Good Fit for This Trial?

This trial is for postmenopausal women aged 60 or above with breast cancer that's either locally advanced or metastatic, and who haven't had hormonal treatment before. They should have a positive hormone receptor status and can have had one chemotherapy line if there's still disease progression.

Inclusion Criteria

I have advanced or metastatic cancer and have had only one chemotherapy treatment.

I am a postmenopausal woman, either by surgery, age, or natural causes.

I have at least one tumor that can be measured and monitored over time.

Exclusion Criteria

I have received hormone therapy for breast cancer.

My cancer has spread to other parts of my body and is life-threatening.

My cancer has not severely affected my liver, brain, or lungs.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either Fulvestrant or Anastrozole as hormonal treatment for breast cancer

38 months

Every 12 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

up to 116 months

12 weekly intervals for survival status

What Are the Treatments Tested in This Trial?

Interventions

• Anastrozole
• Fulvestrant

Trial Overview

The study compares the effects of two drugs on breast cancer: Fulvestrant (FASLODEX) at 500mg versus Anastrozole (ARIMIDEX) at 1mg. It aims to see which drug better slows down disease progression in patients who haven't received prior hormonal therapy.

How Is the Trial Designed?

Group I: faslodex+placebo Experimental Treatment 2 Interventions

Blinded: Fulvestrant 500mg intramuscular injection (2x250mg) plus dummy Anastrozole tablets

Group II: arimidex +placebo Active Control 2 Interventions

Blinded: Anastrozole 1mg tablets plus dummy Fulvestrant intramuscular injection (2x0mg)

Anastrozole is already approved in European Union, United States, Canada, Japan for the following indications:

Approved in European Union as Arimidex for:

• Breast cancer
• Early breast cancer in postmenopausal women

Approved in United States as Arimidex for:

• Adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer
• First-line treatment of postmenopausal women with hormone receptor-positive or hormone receptor unknown locally advanced or metastatic breast cancer

Approved in Canada as Arimidex for:

• Adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer
• Treatment of postmenopausal women with hormone receptor-positive advanced breast cancer

Approved in Japan as Arimidex for:

• Breast cancer

Who Is Running the Clinical Trial?

AstraZeneca

Lead Sponsor

Trials

4,491

Recruited

290,540,000+

Sir Pascal Soriot

AstraZeneca

Chief Executive Officer since 2012

Veterinary Medicine from École nationale vétérinaire d'Alfort, MBA from HEC Paris

Dr. Cristian Massacesi

AstraZeneca

Chief Medical Officer since 2021

MD from Marche Polytechnic University, Oncology training at Royal Marsden Hospital, Kaplan Comprehensive Cancer Center, and European Institute of Oncology

Pascal Soriot

AstraZeneca

Chief Executive Officer since 2012

Veterinary Medicine from École nationale vétérinaire d'Alfort, MBA from HEC Paris

Cristian Massacesi

AstraZeneca

Chief Medical Officer since 2021

MD from Marche Polytechnic University, Medical Oncology training at Royal Marsden Hospital, Kaplan Comprehensive Cancer Center, and European Institute of Oncology

Published Research Related to This Trial

Fulvestrant (Faslodex) is as effective as anastrozole (Arimidex) for treating advanced breast cancer in postmenopausal women, with similar objective response rates across different patient subgroups.

Both treatments provided comparable clinical benefits, making fulvestrant a valuable option for patients with visceral metastases who have not responded to previous endocrine therapies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fulvestrant (Faslodex) versus anastrozole for the second-line treatment of advanced breast cancer in subgroups of postmenopausal women with visceral and non-visceral metastases: combined results from two multicentre trials. Mauriac, L., Pippen, JE., Quaresma Albano, J., et al.[2019]

In a study involving 668 postmenopausal women with advanced breast cancer, anastrozole was found to be as effective as tamoxifen, with similar median time to progression (8.2 months for anastrozole vs. 8.3 months for tamoxifen).

Anastrozole demonstrated a lower incidence of side effects, such as thromboembolic events (4.8% vs. 7.3%) and vaginal bleeding (1.2% vs. 2.4%), suggesting it may be a safer first-line treatment option for advanced breast cancer.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Anastrozole versus tamoxifen as first-line therapy for advanced breast cancer in 668 postmenopausal women: results of the Tamoxifen or Arimidex Randomized Group Efficacy and Tolerability study. Bonneterre, J., Thürlimann, B., Robertson, JF., et al.[2022]

Anastrozole is as effective as tamoxifen for treating advanced breast cancer in postmenopausal women, showing a slightly higher objective response rate (21% vs. 17%) and a significant clinical benefit in 59% of patients compared to 46% for tamoxifen.

Anastrozole offers a significant advantage in time to progression (median of 11.1 months vs. 5.6 months for tamoxifen) and has a lower incidence of side effects, such as thromboembolic events and vaginal bleeding, making it a preferable first-line therapy option.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Anastrozole is superior to tamoxifen as first-line therapy for advanced breast cancer in postmenopausal women: results of a North American multicenter randomized trial. Arimidex Study Group. Nabholtz, JM., Buzdar, A., Pollak, M., et al.[2022]

In a study of 54 postmenopausal women with metastatic breast cancer, fulvestrant demonstrated clinical benefit in 38.9% of patients, with a median time to progression of 6.4 months, indicating its efficacy even after multiple prior treatments.

Fulvestrant was well tolerated, with no severe toxicities (grade 3/4) reported, suggesting it is a safe option for patients with advanced breast cancer who have limited treatment options.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fulvestrant ('Faslodex') in heavily pretreated postmenopausal patients with advanced breast cancer: single centre clinical experience from the compassionate use programme. Mlineritsch, B., Psenak, O., Mayer, P., et al.[2018]

Fulvestrant is a new antiestrogen that has been shown to be effective in treating postmenopausal women with advanced breast cancer, especially after they have not responded to tamoxifen, and it has no partial agonistic effects unlike tamoxifen.

Clinical studies have demonstrated that fulvestrant has comparable efficacy to anastrozole and good tolerance among patients, leading to its approval for use in the USA and EU for those who have progressed on prior anti-estrogen therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Fulvestrant: a new agent in endocrine treatment for breast cancer]. Juretić, A., Sarić, N., Bisof, V., et al.[2018]

In a study of 6241 postmenopausal women with early-stage breast cancer, anastrozole was found to have significantly fewer treatment-related adverse events compared to tamoxifen, indicating better tolerability.

Anastrozole also demonstrated a more favorable risk-benefit profile, with lower rates of serious adverse events and recurrence compared to tamoxifen, making it a preferable option for adjuvant treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comprehensive side-effect profile of anastrozole and tamoxifen as adjuvant treatment for early-stage breast cancer: long-term safety analysis of the ATAC trial. Buzdar, A., Howell, A., Cuzick, J., et al.[2022]

In a retrospective analysis of the ATAC trial, women taking tamoxifen experienced significantly more gynecologic adverse events (34.2%) compared to those taking anastrozole (20.5%), leading to more medical interventions, including a nearly fourfold increase in hysterectomies.

The findings support the use of anastrozole as the preferred initial treatment for early hormone receptor-positive breast cancer due to its lower incidence of gynecologic complications, particularly since most adverse events with tamoxifen occurred within the first 2.5 years.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A lower incidence of gynecologic adverse events and interventions with anastrozole than with tamoxifen in the ATAC trial. Duffy, SR., Distler, W., Howell, A., et al.[2018]

Citations

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Use of anastrozole for breast cancer prevention (IBIS-II)

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10 Years of Arimidex Reduces Recurrence Risk ...

Taking Arimidex for 10 years after breast cancer surgery reduced recurrence risk, but didn't improve overall survival.

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The new results show that women who took Arimidex were 50% less likely to be diagnosed with breast cancer than women who didn't take Arimidex.

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Aromatase Inhibitors and the Risk of Cardiovascular ...

These drugs have been associated with favorable clinical outcomes, including decreased risks of all-cause and breast cancer–related mortality, ...