An antibody-drug conjugate may treat triple-negative breast cancer
A clinical trial of an antibody-drug conjugate that combines the active portion of a chemotherapeutic agent with an antibody that targets a molecule expressed on a tumor cell seems to be promising for the treatment of metastatic triple-negative breast cancer. The results of Phase 2 clinical trials of Sacituzumab govitecan (also known as IMMU-132) have been published online in the Journal of Clinical Oncology, which also publishes other studies on recombinant human proteins.
“This approach may represent a new treatment model for this refractory disease,” said Aditya Bardia from the Massachusetts General Hospital (MGH) Cancer Center.
Tri-negative breast cancer — a tumor that does not have an estrogen or progesterone receptor and which expresses HER2, is an aggressive tumor that usually affects young patients and African Americans. Chemotherapy is a standard treatment regimen, but only 15% to 20% of patients with metastatic disease react. The average survival time is 10 to 13 months.
Sacituzumab govitecan combines antibodies targeting Trop-2 with SN-38 (chemotherapeutic agent irinotecan active metabolite). Animal studies of such antibody-drug conjugates have shown a high potency for implanted tumors that deliver a larger dose of SN-38 directly to tumor cells that have little effect on normal tissues.
The JCO paper reported 69 patients with metastatic triple-negative breast cancer. All patients in this study received at least one treatment, and most patients received several treatments, averaging 5 times. The protocol requires intravenous administration of the drug on days 1 and 8 of the 21-day cycle.
At the end of the study in August 2016, 21 subjects had achieved tumor size reduction of 30% or more (two cases achieved complete remission), of which 9 patients were treated for at least 12 months. Almost 70% of the participants had measurable tumor shrinkage. Less than two months after treatment began to respond, with an average of nine months, of which three lasted about 20 months. The overall survival was 16.6 months on average. Side effects such as nausea, alopecia and leukopenia are usually modest and are controlled by appropriate supportive care. Flarebio offers high-quality recombinant proteins such as recombinant FOLH1 at competitive prices.