Could a Four-Times-a-Year shot replace daily pills for breast cancer?
NCT ID NCT07401381
First seen Jun 27, 2026 · Last updated Jul 24, 2026 · Updated 3 times
Summary
This study tests whether a new quarterly injection of letrozole delivers the same amount of medicine into the body as the standard daily pill. It involves 120 postmenopausal women who have already completed at least 4-5 years of hormone therapy for early breast cancer. The goal is to see if the injection can offer a more convenient dosing option while maintaining similar drug levels and safety.
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Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 1
The first testing in people. Mainly checks safety and dose, usually in a small group.
- Participants
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About 120 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Jun 2026
- Expected to finish
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Oct 2028
An estimate. End dates often move.
- Lead sponsor
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A company
The lead sponsor is a pharmaceutical, biotech, or medical-device company.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 to 80 years
- Sex
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Female participants only
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Women with weight of ≥50 kg and a Body Mass Index (BMI) ≥19 kg/m2 and ≤39 kg/m2 * Postmenopausal women. * Women with confirmed diagnosis of HR+/HER2- or HR+/HER2+ early stage breast cancer who have completed at least 5 years of endocrine therapy, at least 2 years of which were with letrozole. Participants at a low risk of relapse, as assessed by the investigator, can also be eligible after completing 4 years of adjuvant endocrine therapy, at least 2 of which were with letrozole. * Women in good health. * Women who have undergone breast imaging per applicable guidelines (e.g., mammogram) within the last 12 months with no evidence of malignancy (documentation required), and if not done, must be willing to have 1 performed prior to baseline. Exclusion Criteria: * Presence of an uncontrolled, unstable, clinically significant medical condition. * Have used estrogen or progesterone systemic or topical therapy, oral contraceptives, androgens, LH-releasing hormone analogs, prolactin inhibitors, or antiandrogens within 3 months prior to screening. * Use of inducers or inhibitors of CYP3A4 and CYP2A6. * Diagnosed with osteoporosis. * Preexisting cardiovascular disease * Positive result for hepatitis B surface antigen, hepatitis B core antibody, hepatitis C antibody, or HIV antibodies.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
1 site. The list below names each one and where it is.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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Hospital Clínico Universitario Virgen de la Arrixaca (Investigational Site number ESP-009)
RECRUITINGMurcia, Spain
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