Updated data from an ongoing phase 1 clinical trial evaluating ladiratuzumab vedotin in patients with metastatic triple negative breast cancer (TNBC) appear promising and were presented at the 2017 San Antonio Breast Cancer Symposium.
About Triple-negative Breast Cancer
Approximately 12% of breast cancers are TNBC’s meaning that they are estrogen-receptor negative (ER-), progesterone-receptor negative (PR-), and human epidermal growth factor receptor 2-negative (HER2-). This means that TNBC is not stimulated to grow from exposure to the female hormones estrogen or progesterone, nor through an overactive HER2 pathway.
Unfortunately, many available and effective treatment options for the majority of breast cancers block the growth stimulating effects of ER, PR and/or HER2; therefore, TNBC has limited therapeutic options. TNBC tends to be more aggressive and grow at a rapid rate.
There are no modifiable risk factors for TNBC. These cancers tend to occur more frequently in young premenopausal women, in African-American women, and in women who carry the abnormal inherited breast cancer susceptibility gene BRCA1. Novel treatment options for TNBC have lagged behind that of other types of breast cancers and are definitely needed.1
About Ladiratuzumab Vedotin
Ladiratuzumab vedotin is an investigational antibody-drug conjugate (ADC) designed to deliver a potent and clinically validated cell-killing agent, monomethyl auristatin E (MMAE), to cancer cells which express the protein LIV-1. This novel ADC agent is designed to bind to LIV-1 on cancer cells and release the cell-killing agent into target cells upon internalization. Ladiratuzumab vedotin may also cause antitumor activity through other mechanisms, including activation of an immune response.
In the current clinical trial a total of 63 patients with LIV-1-expressing metastatic TNBC were treated with ladiratuzumab vedotin given every three weeks. Patients enrolled in the study had received a median of four prior therapies. Among the evaluable patients with metastatic TNBC, the objective response rate was 25 percent. At the recommended dose, ladiratuzumab vedotin was generally well-tolerated with minimal side effects.
Clinical trail enrollment continues for patients with metastatic TNBC at the recommended dose identified in the trial. Seattle Genetics currently has four clinical studies underway or planned for ladiratuzumab vedotin in breast cancer with a focus on TNBC.
1 Phase 1 Study of the Antibody-Drug Conjugate Ladiratuzumab Vedotin (SGN-LIV1A) in Patients with Heavily Pretreated Triple-Negative Metastatic Breast Cancer (Poster# PD3-14) SANCX 2017