Recent Publications

OPERA-01: A randomized, open-label, phase 3 study of palazestrant (OP-1250) monotherapy vs standard-of-care endocrine therapy for patients with ER+, HER2- advanced breast cancer after endocrine and CDK4/6 inhibitor therapy Poster: 2025 American Society of Clinical Oncology (ASCO) Annual Meeting #TPS1131

OP-3136, a selective KAT6 inhibitor, demonstrates anti-tumor activity in prostate, ovarian, and non-small cell lung cancer preclinical models Poster: 2025 American Association for Cancer Research Annual Meeting #LB166

A Phase 1b/2 Study of Palazestrant (OP-1250) in Combination With Ribociclib in Patients With Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative (ER+/HER2−), Advanced and/or Metastatic Breast Cancer Poster: 2024 San Antonio Breast Cancer Symposium. #P2-09-16

Combining OP-3136, a KAT6 inhibitor, with endocrine therapy and CDK4/6 inhibitor enhances anti-tumor activity in ER+/HER2- breast cancer models Poster: 2024 EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics. #230

Combining palazestrant, a CERAN, and capivasertib, a pan-AKT inhibitor, enhances tumor suppression in ER+/HER2- breast cancer models Poster: 2024 EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics. #212

Combining palazestrant, a CERAN, and everolimus, an mTOR inhibitor, enhances tumor suppression in ER+/HER2- breast cancer models Poster: 2024 EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics. #211

OPERA-01: A randomized, open-label, phase 3 study of palazestrant (OP-1250) vs. standard-of-care treatment for ER+/HER2− advanced or metastatic breast cancer after endocrine and CDK4/6 inhibitor therapy Poster: 2024 American Society of Clinical Oncologists (ASCO) Annual Meeting. #105b

A phase 1b/2 study of palazestrant (OP-1250) in combination with ribociclib in patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, advanced and/or metastatic breast cancer Poster: 2024 ESMO Breast Cancer Annual Congress, #212P

Palazestrant (OP-1250), a complete estrogen receptor antagonist, inhibits wild-type and mutant ER-positive breast cancer models as monotherapy and in combination Molecular Cancer Therapeutics 2024 Mar 4;23(3): 285-300

OPERA-01: A randomized, open-label, phase 3, study of palazestrant (OP-1250) vs standard-of-care treatment for ER+, HER2- advanced or metastatic breast cancer after endocrine and CDK4/6 inhibitor therapy Poster: 2023 San Antonio Breast Cancer Symposium. #PO3-18-09

A phase 1b/2 study of palazestrant (OP-1250), an oral complete estrogen receptor antagonist (CERAN) and selective ER degrader (SERD), with palbociclib in ER-positive, HER2-negative, advanced or metastatic breast cancer patients Poster: 2023 San Antonio Breast Cancer Symposium. #PS15-04

Results from the phase 1/2 study of OP-1250, an oral complete estrogen receptor (ER) antagonist (CERAN) and selective ER degrader (SERD) in patients (pts) with advanced or metastatic ER-positive, HER2-negative breast cancer Oral Presentation: European Society for Medical Oncology (ESMO) Congress 2023. #382MO

The discovery of potent KAT6 inhibitors that demonstrate anti-tumor activity in preclinical models of ER+ breast cancer Poster: 2023 AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics. #A044

A phase 1b dose escalation and expansion study of OP-1250 in combination with ribociclib or alpelisib in patients with advanced and/or metastatic estrogen receptor-positive (ER+)/HER2- breast cancer Poster: 2023 American Society of Clinical Oncology (ASCO) Annual Meeting. #340a

A phase 1b/2 study of OP-1250, an oral complete estrogen receptor antagonist (CERAN) and selective er degrader (SERD) with palbociclib in patients with advanced or metastatic HR+/HER2- breast cancer Poster: 2023 ESMO Breast Cancer Annual Congress. #202P

A phase 1b/2 dose escalation and dose expansion study of OP-1250, an oral complete estrogen receptor antagonist (CERAN)/selective estrogen receptor degrader (SERD), in combination with the CDK4/6 inhibitor palbociclib in patients with advanced and/or metastatic estrogen receptor (ER)-positive, HER2-negative breast cancer (OP-1250-002; NCT05266105) Poster: 2022 San Antonio Breast Cancer Symposium. #P3-07-15

Combination of complete estrogen receptor antagonist, OP-1250, and CDK4/6 inhibitors enhances tumor suppression and inhibition of cell cycle-related gene expression Poster: 2022 San Antonio Breast Cancer Symposium. #P2-24-07

Preliminary phase 1/2 results from OP-1250-001, a study of OP-1250, an oral CERAN/SERD, in patients with advanced and/or metastatic estrogen receptor (ER)-positive, HER2-negative breast cancer (NCT04505826) Poster: 34th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics 2022 #101/PB091

Precision run-on sequencing (PRO-Seq) analysis of a treatment time course in ER+ breast cancer cell lines profiles the transcriptional changes underlying response to complete estrogen receptor antagonist (CERAN) OP-1250 Poster: American Association for Cancer Research Annual Meeting 2022

OP-1250 prevents tumor spread in a model of metastatic mutant ERα+ breast cancer Poster: American Association for Cancer Research Annual Meeting 2022

Preliminary data from a phase 1/2, multicenter, dose escalation study of OP-1250, an oral CERAN/SERD, in patients with advanced and/or metastatic estrogen receptor (ER)-positive, HER2-negative breast cancer Poster: 2021 San Antonio Breast Cancer Symposium. #P1-17-12

The complete estrogen receptor antagonist OP-1250 can combine with HER2 inhibition to inhibit estrogen receptor-driven cellular proliferation and shrink xenograft tumors in ER+/HER2+ breast cancer models Poster: 2021 San Antonio Breast Cancer Symposium. #P5-08-07

A phase 1/2 dose escalation and expansion study of OP-1250 in adults with advanced and/or metastatic hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer Poster: 2021 AACR-NCI-EORTC Virtual International Conference

Complete estrogen receptor (ER) antagonism as an optimal approach for ER-positive breast cancer drug development Poster: 2021 JCA-AACR Precision Cancer Medicine International Conference [Virtual].

The complete estrogen receptor antagonist (CERAN) OP-1250 shrinks ER+ breast cancer tumors expressing the ESR1-Y537S mutant estrogen receptor in an intracranial xenograft model of brain metastases Late-breaking poster: American Association for Cancer Research Annual Meeting 2021 [Virtual]. #LB-122

The complete estrogen receptor antagonist OP-1250 shrinks tumors in xenograft models and has favorable preclinical pharmacokinetic attributes Poster: 2020 San Antonio Breast Cancer Symposium [Virtual]. #PS-18-16

A phase I/II open-label, first-in-human, multicenter, dose escalation and dose expansion study of OP-1250 monotherapy in adult subjects with locally advanced, recurrent, and metastatic hormone receptor (HR)-positive, HER2-negative breast cancer (NCT04505826) Poster: 2020 San Antonio Breast Cancer Symposium [Virtual]. #OT-09-10

Development of OP-1250, an oral complete estrogen receptor antagonist (CERAN) that shrinks ER-positive breast tumors in xenograft models Hodges-Gallagher L, Sun R, Myles DC, Harmon CL, Kushner PJ | Poster: San Antonio Breast Cancer Symposium, December 10-14, 2019. #P5-05-02

OP-1250, a complete estrogen receptor antagonist (CERAN) that penetrates the brain and prevents lethality from intracranial xenograft tumors expressing mutant ESR1 Hodges-Gallagher L, Sun R, Myles DC, et al. | Poster: American Association for Cancer Research Annual Meeting 2020 [Virtual]. #4376

Specific stereochemistry of OP-1074 disrupts estrogen receptor alpha helix 12 and confers pure antiestrogenic activity Fanning SW, Hodges-Gallagher L, Myles DC, et al. | Nature Communications. 2018;9:2368.

OP-1250: a potent orally available complete antagonist of estrogen receptor-mediated signaling that shrinks wild type and mutant breast tumors. Hodges-Gallagher L, Sun R, Myles DC, Harmon CL, Kushner PJ, Poster: ENA 2020: EORTC-NCI-ACCR: 32nd Symposium [Virtual]