NCT07401381From ClinicalTrials.govRecruiting

A Study to Compare the Steady-State Bioavailability of Injectable Letrozole SIE and Oral Letrozole in Post-Menopausal Women With Hormone Receptor Positive Early Breast Cancer

An Open-Label, One-Sequence Study to Evaluate the Steady-State Comparative Bioavailability of Quarterly Letrozole SIE and Once Daily 2.5 mg Oral Letrozole (Femara®) in Post-Menopausal Women Treated With Endocrine Therapy for Hormone Receptor-Positive Early Breast Cancer. (SIE-1)

Hormone Receptor Positive Early Breast Cancer

At a glance

Phase: Phase 1
Study type: Interventional
Sponsor: Rovi Pharmaceuticals Laboratories
Enrolment target: 120
Started: 8 June 2026
Main results due: May 2028
Study sites: 19
Registry updated: 23 September 2026

Can you take part?

Ages 18 years to 80 years.
Women only.
You need the condition being studied — healthy volunteers are not accepted.

These are the headline rules only. Every study has a longer list, and whether you are eligible is decided by the research team at the site — never by this page.

Read the full eligibility criteria

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.

What this study is about

In the sponsor’s own words, from the registry.

The study aims to compare the amount of the drug letrozole that gets into the bloodstream after multiple doses of the quarterly injection Letrozole SIE, versus multiple doses of the standard oral daily tablet of letrozole (Femara®), in women who have gone through menopause and have received treatment for hormone receptor-positive early breast cancer. Participants must have completed at least five years of hormone therapy with at least two of those years with letrozole before starting their participation in the study. Women who have completed four years of hormone therapy are also eligible if their doctor considers them at low risk of cancer returning.

Study sites(19)

Precision NextGen Oncology and Research Center (Investigational Site number USA-001)
Beverly Hills, California, United States
Recruiting
D&H National Research Centers INC (Investigational Site number USA-002)
Margate, Florida, United States
Recruiting
United Medical Research (Investigational Site number USA-005)
Port Orange, Florida, United States
Recruiting
Investigational Site number SRB-004
Belgrade, Serbia
Recruiting
Investigational Site number SRB-002
Belgrade, Serbia
Recruiting
Investigational Site number SRB-001
Kamenitz, Serbia
Recruiting
Investigational Site number SRB-003
Kragujevac, Serbia
Recruiting
Investigational Site number SRB-005
Niš, Serbia
Recruiting
Hospital Universitario Fundación Alcorcón (Investigational Site number ESP-015)
Alcorcón, Spain
Recruiting
NEXT Oncology. Phase I Unit / IOB - Hospital Quironsalud Barcelona (Investigational Site number ESP-002)
Barcelona, Spain
Recruiting
Hospital Universitario Virgen de las Nieves (Investigational Site number ESP-011)
Granada, Spain
Recruiting
Complejo Asistencial Universitario de León - Hospital de León (Investigational Site number ESP-013)
León, Spain
Recruiting
Hospital Universitario Arnau de Vilanova de Lleida (Investigational Site number ESP-003)
Lleida, Spain
Recruiting
Althaia Xarxa Assistencial Universitària de Manresa F.P (Investigational Site number ESP-012)
Manresa, Spain
Recruiting
Hospital Quirónsalud Málaga (Investigational Site number ESP-001)
Málaga, Spain
Recruiting
Hospital Clínico Universitario Virgen de la Arrixaca (Investigational Site number ESP-009)
Murcia, Spain
Recruiting
NEXT Oncology Phase I Unit - Hospital Universitario Quironsalud Madrid (Investigational Site number ESP-008)
Pozuelo de Alarcón, Spain
Recruiting
Consorci Corporació Sanitària Parc Taulí - Hospital de Sabadell (Investigational Site number ESP-006)
Sabadell, Spain
Recruiting
Hospital Clinico Universitario Santiago de Compostela (Investigational Site number ESP-007)
Santiago de Compostela, Spain
Recruiting

Showing 19 of 19 sites. 19 of the 19 sites on this study are recruiting right now — a site can stop enrolling while the study as a whole is still open.

Source: ClinicalTrials.gov record NCT07401381. Trialion does not run this study, is not paid to refer anyone to it, and cannot enrol you. Eligibility is always decided by the research team at the site.

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