An experimental “magic bullet” drug has the potential to change the way women are treated for one of the most deadly forms of breast cancer, an expert has said.
Sacituzumab, is an antibody that zeroes in on cancer cells. Like a homing missile, it delivers a “warhead” in the form of a potent chemotherapy drug.
Since it directly targets tumours while avoiding healthy cells, side effects are kept to a minimum.
In a clinical trial involving 108 women with triple-negative breast cancer that had spread around the body, the infused drug caused “significant” tumour shrinkage, researchers reported.
The women had all previously failed to respond to two or more previous treatments. All had a poor prognosis.
Overall, a third of the patients responded to the drug and typical survival time was 13 months. Nine long-term responders remained free of any disease progression for more than a year.
Senior investigator Dr Kevin Kalinsky, from Columbia University, New York, said: “I think this drug has the potential to change practice, because the data looks so compelling, even with the relatively small number of patients in the trial.
“There’s an unmet need for patients with metastatic (spreading) triple-negative breast cancer, and we see significant tumour shrinkage with this new therapy.”
Triple negative breast cancers are notoriously hard to treat. They are impervious to normal types of hormone therapy and drugs that target the cancer-fuelling HER-2 protein.
The new drug is also being tested against other types of breast cancer as well as bladder and prostate cancers, said researchers writing in the New England Journal of Medicine.
During the trial only 3% of patients stopped taking the drug due to adverse side effects. The main effects seen were hair loss, diarrhoea and fatigue.
Dr Kalinsky added: “Having smaller tumours can be incredibly meaningful to a patient’s quality of life. When tumours shrink, patients are more likely to experience improvement in symptoms, like pain.”