Phase 2
Completed N=153
A Dose Escalation/Expansion Study of Oral OP-1250 in Subjects With Advanced and/or Metastatic HR+, HER2- Breast Cancer
Hormone Receptor Positive Breast Carcinoma · HER2-negative Breast Cancer
Source: ClinicalTrials.gov NCT04505826 ↗
Enrolled (actual)
153
Serious AEs
20.9%
Results posted
May 2026
Primary outcomePrimary: Dose Limiting Toxicities (DLT) — 0; 0; 0; 0 Participants
Summary
This clinical trial is a Phase I dose escalation and dose expansion and Phase II monotherapy open-label, first-in-human, multicenter study of OP-1250 in adult subjects with advanced and/or metastatic hormone receptor (HR)-positive, her2-negative breast cancer.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Dose Limiting Toxicities (DLT) |
0; 0; 0; 0; 0; 0 | — |
| PRIMARY Characterize the Incidence of Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs) of OP-1250 That Had at Least One Treatment Emergent Adverse Event |
5; 29; 5; 79; 5; 7 | — |
| PRIMARY Pharmacokinetics of OP-1250 |
1956; 4014; 7668; 9163; 12580; 22439 | — |
| PRIMARY Anti-tumor Activity of OP-1250 (cPR) |
0; 2; 0; 4; 0; 0 | — |
Eligibility Criteria
Key Inclusion Criteria
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
- Must have received at least 1 prior hormonal regimen and at least 6 months of a prior continuous endocrine therapy for locally advanced or metastatic disease
- Must not have received prior oral endocrine therapy < 2 weeks prior to first dose
- Must not have received prior, chemotherapy in 2 weeks or within 5 half-lives whichever is earlier, antibody therapy within 4 weeks or investigational therapy within 4 weeks or 5 half-lives whichever is earlier, prior to the first dose
- Adequate hepatic function
- Adequate renal function
- Normal coagulation panel
- Willingness to use effective contraception
Key Exclusion Criteria
- Gastrointestinal disease
- Significant renal disease
- Significant cardiovascular disease
- Significant ECG abnormalities
- Ongoing systemic bacterial, fungal, or viral infection (requiring antimicrobial therapy)
- Pregnancy or breastfeeding
Data sourced from ClinicalTrials.gov (NCT04505826). 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.