Chandigarh: In a recent finding that could provide a new explicit tool in breast cancer therapy, researchers from Post-graduate Institute of Medical Education and Research (PGIMER), Chandigarh have shown that the in-house developed "Lu-177-trastuzumab" effectively kills breast cancer cells.
In their study, a team led by Dr. Jaya Shukla from PGIMER, analysed 10 patients from two different type of breat cancer. Out of 10 patients, 6 were HER2 positive and 4 were HER2 negative. The preliminary pilot study showed that Lu-177-trastuzumab has specific targeting ability for HER2 positive tumors. The study was published in "International Journal of Cancer".
"Breast cancer is the most common type of cancer in women. Amongst the different types of breast cancers, HER2 positive are most aggressive and are associated with poor prognosis," says Dr. Priya Bhusari. Conventional treatment strategies for such breast cancer include surgery, radiotherapy and chemotherapy. The front line treatment options sometimes fail to work in advanced stages of tumor, especially in case of metastatic disease.
Study author Dr. Jaya Shukla said: "Trastuzumab is an FDA approved humanized monoclonal antibody that targets HER2 positive cancer cells. However, patients with metastatic breast cancer develop resistance to trastuzumab therapy within a year." Therefore, in order to improve the efficacy of therapy, the team radiolabelled trastuzumab using Lu-177. Lu-177 is a therapeutic isotope and previously has been in use for radionuclide therapy of neuroendocrine tumors.
A breakthrough clinical study was carried out on ten patients using Lu-177-trastuzumab. In the trial, every patient was given the drug and subsequently CT Scan with other molecular imaging techniques were performed to monitor its effectiveness which showed very promising results.
"The study is the first-in-human study evaluating the feasibility of using Lu-177-trastuzumab, a radiopharmaceutical," Dr. Bhusari says. "The study is interesting because it has combined the use of beta radiation (for cell killing) and the antibody (trastuzumab), which imparts synergistic effect to kill the tumor cells, ultimately improving the efficacy of treatment for HER2 positive tumors.
Dr. Jaya added, "Lu-177-trastuzumab is developed to deliver therapeutic radiation to cancer and spare the healthy tissue." The new study is likely to change the way breast cancer management is carried and could ultimately lead to new ways to treat many other malignancies also. Experts believe the medication will minimise side-effects. Lu-177-trastuzumab may prove to be a potential palliative agent for HER2 metastatic breast disease which may improve the quality of life of these patients especially when other conventional treatments fails.
*'Scientist at Dr B R Ambe-dkar Center for Biomedical Research (ACBR), Univer-sity of Delhi, Delhi.'