Phase 1
Completed N=62
MEN1611 With Trastuzumab (+/- Fulvestrant) in Metastatic Breast Cancer
Advanced or Metastatic Breast Cancer
Source: ClinicalTrials.gov NCT03767335 ↗
Enrolled (actual)
62
Serious AEs
41.9%
Results posted
Jun 2025
Primary outcomePrimary: MTD of MEN1611 in Combination With Trastuzumab ± Fulvestrant — 48 milligrams (mg)
Summary
The main purpose of this open-label, dose-escalation, phase Ib study is to identify the appropriate dose of MEN1611 to be used in combination with Trastuzumab with/without Fulvestrant for the treatment of advanced or metastatic HER2-positive breast cancer
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY MTD of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
48 | — |
| PRIMARY Number of Participants With DLTs of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
0; 0; 0 | — |
| PRIMARY RP2D of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
48 | — |
| SECONDARY Best Overall Response (BOR) of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
0; 0; 4.8; 0; 66.7; 35.7 | — |
| SECONDARY Objective Response Rate (ORR) of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
0; 66.7; 40.5 | — |
| SECONDARY Disease Control Rate (DCR) of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
33.3; 100; 88.1 | — |
| SECONDARY Duration of Response (DOR) of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
224; NA; 114 | — |
| SECONDARY Progression-free Survival (PFS) of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
62; 203; 167 | — |
| SECONDARY Overall Survival (OS) of MEN1611 in Combination With Trastuzumab ± Fulvestrant |
120; 203; 989 | — |
Eligibility Criteria
Main Inclusion Criteria:
- Histologically confirmed invasive adenocarcinoma of the breast
- Known HER2+ breast cancer
- Advanced or metastatic breast cancer harbouring PIK3CA mutation on tissue sample
- > 2 lines of anti-HER2 based regimens with at least 1 regimen with trastuzumab
- Radiological documented evidence of progressive disease
- Life expectancy ≥ 12 weeks
- Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2
Main Exclusion Criteria:
- Previous treatment with PI3K inhibitors
- Brain metastases untreated, unless treated > 4 weeks and only if clinically stable and not receiving corticosteroids
- History of clinically significant bowel disease
- ≥ grade 2 diarrhoea
- History of significant, uncontrolled, or active cardiovascular disease
- Any serious and/or unstable pre-existing psychiatric or neurologic illness or other conditions that could interfere with patient's safety
- Not controlled diabetes mellitus (glycated haemoglobin [HbA1c] >7%) and fasting plasma glucose >126 mg/dL
- Concurrent chronic treatment with steroids, as immunosuppressant, or another immunosuppressive agent
Data sourced from ClinicalTrials.gov (NCT03767335). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.