Clinical trial · Interventional
Intermittent Letrozole Therapy in Postmenopausal Women With Metastatic Breast Cancer
A Phase II Clinical Trial of Intermittent Letrozole Therapy in Postmenopausal Women With CA 15-3 Positive (Carcinoma Antigen 15-3), Hormone Receptor Positive, Metastatic Breast Cancer
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Why stopped (as posted): Slow Accrual
Summary
Brief summary (as posted)
The purpose of this research study is to study the effects of using aromatase inhibitor (AI) therapy intermittently on participants with breast cancer. AIs are a class of drugs used to treat breast cancer in postmenopausal women. They work by decreasing the level of estrogen, which is believed to stimulate the growth of tumor tissue. Breast cancer that progresses despite therapy with an AI is thought to have become resistant to AI therapy. There is scientific evidence to suggest that resistant breast cancer cells learn to grow at the very low levels of estrogen present on AI therapy, and that increasing estrogen levels even slightly by stopping AI therapy may inhibit the breast cancer cells.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Breast Cancer | Malignant Breast Neoplasm | CURATED_EXACT | 0.92 |
Interventions
Interventions (1)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Letrozole | Drug | Letrozole | ALIAS |
Design
Arms and outcomes
Arms (1)
- type
- EXPERIMENTAL
- label
- Intermittent letrozole therapy
- description
- Letrozole 2.5 mg administered by mouth daily during each 28 day treatment cycle. Treatment is intermittent with possible breaks between each 28 day treatment cycle based on CA 15-3 or CA 27.29 levels. Letrozole is administered until the participant has disease progression as determined by RECIST (Response Evaluation Criteria In Solid Tumors), experiences severe side effects, or decides to stop treatment.
- interventionNames
- Drug: Letrozole
Primary outcomes (1)
- measure
- Number of Patients With Decline in Serum CA 15-3 (Carcinoma Antigen 15-3)
- timeFrame
- 3 years
- description
- The Number of patients that have have a response of a decrease in CA 15-3 or CA 27.29 levels by at least 50% of that individual patient's baseline or peak level after re-introducing Letrozole therapy following a break in therapy as described in the intervention.
Secondary outcomes (2)
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 18 Years
Show eligibility criteria text
Inclusion Criteria: * Female * 18 years of age or older * Postmenopausal * Histologically or cytologically confirmed adenocarcinoma of the breast with locally advanced or metastatic disease this is not considered amenable to curative treatment with elevation of CA 15-3 documented at the time of diagnosis of metastatic disease and prior to initiation of letrozole or anastrozole therapy * Current letrozole or anastrozole monotherapy with a documented CA 15-3 level that has decreased by at least 50% of the patients baseline * Letrozole or anastrozole must be discontinued at the time of study enrollment * Evidence of hormone sensitivity of primary or secondary tissue. * Measurable or nonmeasurable (but evaluable-defined as nontarget lesions) disease according to modified RECIST * Prior antiestrogen therapies including tamoxifen, steroidal AIs, nonsteroidal AIs, or fulvestrant in the adjuvant setting is allowed provided the patient is currently on letrozole or anastrozole monotherapy as first-line therapy for metastatic disease * Life expectancy of greater than 3 months * ECOG (Eastern Cooperative Oncology Group) Performance Status of 0,1, or 2 * Normal organ and marrow function as outlined in protocol Exclusion Criteria: * Premenopausal * Trastuzumab or biologic therapy within 2 weeks * Prior or planned radiation therapy to a site of evaluable disease in the event that the site is the only site of evaluable disease * Concomitant anticancer treatments including trastuzumab, chemotherapy, or other biologic agents other than letrozole or anastrozole therapy * Chronic bisphosphonates for hypercalcemia or prevention of bone metastases. * Treatment with non-approved or investigational agent within 2 weeks before study entry * Presence of life-threatening metastatic disease, defined as extensive hepatic involvement, or past or present brain or leptomeningeal involvement, or symptomatic pulmonary lymphangitic spread * Patients who are highly symptomatic from their breast cancer, or who require urgent palliative chemotherapy, as decided by their treating physician * Previous or current systemic malignancy within the past five years, except for contralateral breast carcinoma, in situ carcinoma of the cervix treated by cone biopsy, or adequately treated basal or squamous cell carcinoma of the skin. * Any severe concomitant condition believed to render subject undesirable for participation
References
Publications (0)
Data not yet available