A clinical trial conducted by the Massachusetts General Hospital Cancer Center, US, demonstrated that the antibody-drug conjugate sacituzumab govitecan (IMMU-132) can target cancer cells and shrink tumours in women with triple negative breast cancer (TNBC).
Developed by fusing a chemotherapy treatment to an antibody, the drug targets Trop-2 that is reported to be found at high levels on the surface of several cancer cells, to selectively deliver the active metabolite of irinotecan called SN-38.
It was found that the sacituzumab govitecan was well tolerated, and triggered early and durable responses in heavily pretreated patients.
The single-arm, multi-centre trial evaluated the efficacy and safety of sacituzumab govitecan in 69 patients with relapsed / refractory metastatic TNBC who have received at least one previous therapy.
The trial's primary endpoints were safety and objective response rate, while the secondary endpoints determined progression-free and overall survival.
According to Cancer Research UK Professor Peter Schmid, while the responses to this treatment are promising, further investigation is required to find out which patients with TNBC are most likely to benefit from the treatment.
The results showed that the tumours shrank by 30% or more in 21 of the 69 women who received the drug.
While it is reported that tumours completely disappeared in two patients, about 70% experienced shrinkage to certain extent.
The drug will be further evaluated to study its effects in patients with earlier-stage disease as a combination therapy, as a treatment option for other forms of breast cancer.
Image: Massachusetts General Hospital. Photo: courtesy of InvictaHOG/Wikipedia.