A Window of Opportunity Study of Endocrine Therapy With and Without Prometrium in Postmenopausal Women With Early Stage Hormone Receptor-positive Breast Cancer.
This Phase II trial, sponsored by St Vincent's Hospital, investigates the efficacy of pre-operative endocrine therapy with and without Prometrium (progesterone) in postmenopausal women with early-stage HR+ HER2- breast cancer. The study aims to explore potential additive effects of progesterone on standard endocrine therapies (letrozole and tamoxifen). Given the significant market for breast cancer therapies, particularly in hormone receptor-positive subtypes, successful outcomes could enhance treatment options and market share for involved therapies. The trial's findings may also influence future treatment guidelines and positioning of Prometrium in combination therapies, potentially impacting competitive dynamics in the oncology space.
Indication: Early-stage Breast Cancer
Modality: small molecule
Target: Estrogen Receptor (ER) and Progesterone Receptor (PR) modulation in breast cancer.
Sponsor: St Vincent's Hospital
Source URL: ClinicalTrials.gov
Source updated: Detailed source ingestion pending
Ingested: Jul 09, 2026
Model: trialsignal-ai-v1
Validation: validated
Matched by target_normalized: Estrogen Receptor (ER) and Progesterone Receptor (PR) modulation in breast cancer.
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Condition raw: Early-stage Breast Cancer, Hormone Receptor Positive Tumor
Condition normalized: Early-stage Breast Cancer, Hormone Receptor Positive Tumor
Modality raw: small molecule
Modality normalized: small molecule
Target raw: Estrogen Receptor (ER) and Progesterone Receptor (PR) modulation in breast cancer.
Target normalized: Estrogen Receptor (ER) and Progesterone Receptor (PR) modulation in breast cancer.