Clinical trial Recruiting at 1 site Phase 2 Interventional Ages 18 and up

Elacestrant and Exemestane for HR+/HER2- Breast Cancer with FES-PET Positive Lesions

Official title: Elacestrant and Exemestane for Patients With Pretreated HR+/HER2- Metastatic Breast Cancer and [18F] FES-avid Lesions (COMBINE): a Proof-of-concept Phase 2 Clinical Trial

Run by European Institute of Oncology · NCT07395336 · Data updated 2026-11-12

This study tests a combination of elacestrant and exemestane in adults with pretreated HR+/HER2- metastatic breast cancer who show FES-PET uptake on scans.

More Breast Cancer trials

Quick facts

PhasePhase 2
Study typeInterventional
Ages18 Years and up
SexAll
Enrollment26 (estimated)
SponsorEuropean Institute of Oncology
Academic / other
Drugs / interventionsradiation, chemotherapy
Locations1 site (Milan, Italy)
StatusRecruiting
StartedMay 11, 2026
Main results expectedDecember 2028
Study endsDecember 2028
Registry record updatedMay 14, 2026
Trial IDNCT07395336 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults (18+) with HR+/HER2- metastatic or unresectable breast cancer, progressed after prior therapy, with FES-PET avid lesions and no rapid visceral crisis.

Probably not a fit

Patients without adequate FES-PET avidity, those with rapidly advancing disease, or those not suitable for endocrine therapy may not benefit.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This Phase 2 interventional trial explores whether combining two endocrine therapies, elacestrant and exemestane, can benefit patients whose HR+/HER2- breast cancer has progressed after prior treatments. Eligibility requires measurable or evaluable bone disease and substantial lesion avidity on 18F-FES-PET imaging, indicating estrogen receptor expression. The study targets patients who are appropriate for endocrine therapy without immediate visceral crisis and who have progressed after CDK4/6 inhibitor-based therapy. The approach uses imaging-guided selection to identify those likely to respond to continued endocrine strategies. Outcomes will inform whether this combination can improve disease control with manageable toxicity.

Why it matters

Potential benefit: If successful, patients may experience longer periods without disease progression and better disease control using hormonal therapy.

How similar studies have gone: Earlier studies support the use of endocrine therapies in this setting, with FES-PET showing promise for selecting responsive patients.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Must be at least 18 years old;
2. Must have a histologically- or cytologically-proven diagnosis of carcinoma of the breast with evidence of either locally advanced disease not amenable to resection or radiation therapy with curative intent or metastatic disease not amenable to curative therapy
3. Must be appropriate candidates for endocrine therapy (no visceral crisis, highly symptomatic disease or rapidly progressing disease)
4. Must have 1 of the following as defined by RECIST v1.1:

   1. Measurable disease
   2. Bone only disease with evaluable lesions. Subjects must have at least 1 lytic or mixed lytic/blastic bone lesion; blastic lesions only are not evaluable and allowed. Subjects who have had prior radiation to bone must have at least 1 evaluable lesion in a nonirradiated area.
5. ≥50% of measurable lesions defined as avid (SUVmax≥1.5) at 18F-FES-PET/CT;
6. Must have HR+ and HER2- disease at the last previous biopsy. ER and HER2 testing must be performed in the following manner:

   1. Documentation of ER+ tumor with ≥ 10% staining by immunohistochemistry (IHC), with or without PgR positivity AND
   2. Documentation of HER2- tumor with an IHC result of 0 or 1+ for cellular membrane protein expression or an in situ hybridization negative result as defined in the 2023 ASCO recommendations for HER2 testing (Wolff, 2013; Wolff, 2018; Wolff 2023)

8\. Must have progressed during or within 28 days of completion of prior treatment with a CDK4/6 inhibitor in combination with anastrozole or letrozole (+ LHRH agonist for male or premenopausal female patients).

1. This treatment has to be received in first line setting for metastatic disease (with abemaciclib, ribociclib or palbociclib)
2. Discontinuation of prior CDK4/6 inhibitor due to toxicity, in the absence of progression, will not fulfill this criterion
3. Patients must have received the combination treatment for at least 12 months and there must have been evidence of disease control (stable disease \[SD\], partial response \[PR\] or complete response \[CR\] as best response) 9. Must have received no other treatment after the CDK4/6 inhibitor combined with endocrine therapy 10. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1

Exclusion Criteria:

1. Prior treatment with fulvestrant, elacestrant or investigational SERD or ER antagonist in metastatic or early disease (e.g., D-0502, GDC-0810, GDC-0927, GDC-9545, G1T-48, LSZ102, AZD9496, SAR439859, ZN-c5, H3B-6545, bazedoxifene, lasofoxifene)
2. Prior treatment with tamoxifen or SERD alone or combined with CDK4/6i in metastatic setting
3. Any other endocrine therapy \< 14 days before first dose of study drug
4. Any prior treatment after first line with CDK4/6i in metastatic setting
5. Bisphosphonates or RANKL inhibitors initiated or dose changed \< 3 months prior to first dose of study drug
6. Radiation therapy within 14 days (28 days for brain lesions) before the first dose of study drug

Where it's running

  • European Institute of Oncology
    Milan, Italy, Italy
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.