Sacituzumab govitecan (brand name Trodelvy) has been approved by the European Commission as a monotherapy for adult patients with unresectable or metastatic HR+/HER2- breast cancer, its manufacturer Gilead has announced.
The approval relates to those who have received endocrine-based therapy and at least two additional systemic therapies in the advanced setting, and was based on the findings of the TROPiCS-02 study.
This global, multi-centre, open-label, Phase 3 study, evaluated Trodelvy versus the physician’s choice of chemotherapy (eribulin, capecitabine, gemcitabine or vinorelbine). A total of 543 patients with HR+/HER2- metastatic breast cancer who were previously treated with endocrine therapy, CDK4/6 inhibitor and two to four lines of chemotherapy for metastatic disease were randomised 1:1.
The primary endpoint was progression-free survival per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) as assessed by blinded independent central review for participants treated with Trodelvy compared to those treated with chemotherapy.
Secondary endpoints included overall survival, overall response rate, clinical benefit rate and duration of response, as well as assessment of safety and tolerability and quality of life measures.
Sacituzumab govitecan clinical efficacy
In the trial, sacituzumab govitecan gave rise a statistically significant and clinically meaningful overall survival benefit compared to the single-agent chemotherapy (median overall survival = 14.4 vs 11.2. Hazard ratio, HR = 0.79, 95% CI 0.65 – 0.96, p = 0.02).
In addition, sacituzumab govitecan demonstrated a 34% reduction in risk of disease progression or death (median progression-free survival: 5.5 vs 4.0 months, HR = 0.66, 95% CI 0.53 – 0.83, p = 0.0003). In fact, three times as many patients treated with sacituzumab govitecan were progression-free at one year versus those treated with chemotherapy (21% vs 7%).
Head of the International Breast Cancer Center, in Madrid and Barcelona, Spain, Dr Javier Cortes, said: ‘The European approval of sacituzumab govitecan is an important milestone for the European breast cancer community. We now have a new treatment option that has delivered a proven and clinically meaningful survival benefit for women in Europe with pre-treated HR+/HER2- metastatic breast cancer.‘
Metastatic breast cancer prevalence
Hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer is the most common type of breast cancer and accounts for approximately 70% of all new cases. Almost one in three cases of early-stage breast cancer eventually become metastatic, and the five-year relative survival rate among patients with HR+/HER2- metastatic disease is 34%.
Since patients with HR+/HER2- metastatic breast cancer become resistant to endocrine-based therapy, their primary treatment option is limited to single-agent chemotherapy. In this setting, it is common to receive multiple lines of chemotherapy regimens over the course of treatment yet the prognosis remains poor.
Sacituzumab govitecan is a first-in-class Trop-2 directed antibody-drug conjugate. Trop-2 is a cell surface antigen highly expressed in multiple tumour types, including in more than 90% of breast and bladder cancers. Sacituzumab govitecan is intentionally designed with a proprietary hydrolysable linker attached to SN-38, a topoisomerase I inhibitor payload. This unique combination delivers potent activity to both Trop-2 expressing cells and the microenvironment.
In data presented recently at ASCO 2023, the combination of ribociclib and standard endocrine therapy was found to improve invasive disease-free survival rates more than endocrine therapy alone in patients with early stage HR+/HER2- breast cancer.