Things to Know About New Breast Cancer Drug | May Stop Tumor Growth and Extend Survival

Breast cancer is the second largest cause of death from cancer in women.

According to the American Cancer Society, breast cancer fatality rates in women under the age of 50 have been steady since 2007. In the United States, there is a chance of every 1 in 8 women developing this fatal illness at some point in her life. Hence, proper screening and awareness surrounding breast cancer have become increasingly important. Scientists have been tirelessly working on new drug formulas for the treatment and prevention of breast cancer.

In a ray of hope, a breakthrough drug, Enhertu, used to treat metastatic breast cancer has demonstrated exceptional success, increasing patients' survival rate by six months. The study which was published in The New England Journal of Medicine, says that the drug "resulted in significantly longer progression-free and overall survival than the physician's choice of chemotherapy."

Mary Smrekar, 55, a patient in the current study was diagnosed with breast cancer in 2010 and has undergone surgery, chemotherapy and radiation. After her cancer returned in 2019, chemotherapy helped little. After entering into the study, her tumors have stopped growing though her cancer hasn't gone away. “I’m so happy I got another two years,” Ms. Smrekar said. “My daughter is getting married next month. I didn’t think I’d make it to the wedding.”

The study was led by Dr. Shanu Modi and their team of professional doctors and researchers. Dr. Modi received a standing ovation for, as they presented the study at the American Society of Clinical Oncology. 

The clinical trial included 557 patients with metastatic breast cancer who were classified as HER2-low, meaning they had few HER2 cells. Enhertu, according to the study, targets and blocks HER2, a protein that stimulates the proliferation of cancer cells. Patients with few HER2 cells were not helped by the existing drugs because the cancer cells evaded chemotherapy treatments. As per Dr. Halle Moore, director of breast medical oncology at the Cleveland Clinic, 80% to 85% of breast cancer patients fell under this category.

Two-thirds of these patients took the new drug, Enhertu while the rest underwent standard chemotherapy. Individuals who received Enhertu had their tumors halt growing for 10.1 months, compared to 5.4 months for patients who received standard chemotherapy. Furthermore, Enhertu extended overall survival to 23.4 months, compared to 16.8 months for those receiving conventional therapy.

Dr. Eric Winer, a breast cancer specialist and director of the Yale Cancer Center told The New York Times, "This strategy is the real breakthrough. This is about more than just this drug or even breast cancer. Its real advantage is that it enables us to take potent therapies directly to cancer cells." However, Dr. Winer also emphasized that it is not a drug for earlier-stage breast cancer as it is yet to be tested in that group of patients.

Dr. Moore told the outlet that successful clinical trials often add a few weeks of life but show no improvements in terms of survival. Moore added, "It is unheard-of for chemotherapy trials in metastatic breast cancer to improve survival in patients by six months."

On May 4, the Food and Drug Administration authorized Enhertu for adult patients with unresectable or metastatic HER2-positive breast cancer.

References:

https://www.cancer.org/cancer/breast-cancer/about/how-common-is-breast-cancer.html

https://www.nejm.org/doi/full/10.1056/NEJMoa2203690

https://twitter.com/MSKCancerCenter/status/1533533014004797445?s=20&t=5_ZJU5lMm_23IkciVAFaqQ

https://www.nytimes.com/2022/06/07/health/enhertu-breast-cancer-chemotherapy.html

Representative Cover Image Source: Getty Images/Panuwat Dangsungnoen