Laboratorios Farmacéuticos ROVI S.A. (hereinafter, “ROVI”) has announced that it has received the first regulatory approvals in the United States, Georgia and Serbia to conduct the Phase III SIE-31 clinical trial, with which it aims to evaluate the safety and efficacy of the investigational product compared with the reference medicine, both of which are administered in combination with a CDK4/6 inhibitor, in postmenopausal women with hormone receptor-positive (HR+), HER2 negative (HER2-) locally advanced or metastatic breast cancer.
This clinical trial forms part of ROVI’s LAISOLID project, funded by the Technological Development and Innovation Centre (CDTI) under Spain’s Recovery, Transformation and Resilience Plan associated to the IPCEI Med4Cure programme.
Letrozole SIE (“Superior Inhibition of Estrogens”) is an investigational medicine that ROVI is developing to treat postmenopausal women with hormone receptor-positive breast cancer. It is a long-acting injectable (LAI) formulation designed to obtain sustained and stable oestrogen suppression for several months, which could have a positive impact on disease progression.
The preliminary results of the clinical development programme for Letrozole SIE have allowed progression to the next stages of clinical development. As the company has reported, this programme follows a stepwise development approach that includes clinical studies aimed to characterise the pharmacokinetic, bioavailability, efficacy and safety of the medicine.
The SIE-3 study is a multicentre, randomised, double-blind, double-dummy Phase III study. Its objective is to demonstrate the efficacy and safety of Letrozole SIE compared with oral letrozole, both administered in combination with a CDK4/6 inhibitor), in patients with HR+/HER- locally advanced or metastatic breast cancer.
Receiving the first regulatory approvals in the United States, Georgia and Serbia represents an important milestone in the development programme and enables ROVI to advance the international launch of the study.
About the SIE-31 clinical trial
Study title: A Multicenter, Randomized, Double-Blind, Double-Dummy Phase 3 Study to Evaluate the Safety and Efficacy of Letrozole SIE Compared to Femara®2 (combined with a CDK4/6 inhibitor) in Postmenopausal Women with HR-Positive, HER2-Negative, Locally Advanced or Metastatic Breast Cancer.
Protocol number ROVI: ROV-SIE-2025-02 (ClinicalTrials.gov ID NCT07340658).
Design: multicentre, randomised, double-blind, double-dummy Phase III clinical trial.
Population: postmenopausal women with HR-positive, HER2-negative locally advanced or metastatic breast cancer.
Primary objective: to evaluate the efficacy and safety of the investigational product compared with the oral formulation, both combined with a CDK4/6 inhibitor.
About HR-positive/HER2 negative breast cancer
HR-positive/HER2-negative breast cancer is the most frequent subtype of breast cancer. In postmenopausal women with locally advanced or metastatic disease, endocrine therapy is one of the cornerstones of treatment and can be administered in combination with CDK4/6 inhibitors in accordance with routine clinical practice and international treatment guidelines3.
1 A Study to Investigate the Efficacy and Safety of Letrozole SIE Compared With Femara® (Both Combined With the CDK4/6 Inhibitor Ribociclib) in Postmenopausal Women With HR-Positive, HER2-Negative, Inoperable Locally Advanced or Metastatic Breast Cancer (SIE-3). ClinicalTrials.gov ID NCT07340658 [https://clinicaltrials.gov/study/NCT07340658].
2 Is a medicinal product owned by Novartis Farmacéutica, S.A.
3 European Society for Medical Oncology (ESMO). Breast cancer guidelines. https://www.esmo.org/guidelines/esmo-clinical-practice-guidelines-breast-cancer
