New drug reduces risk of breast cancer progression

A new oral drug developed by the pharmaceutical AstraZeneca significantly reduces the tumor progression in women with breast cancer with estrogen receptor (ER) positive and HER2 negative. The drug is called camizestrant and a phase two trial (Serena-2), coordinated by the Vall d’Hebron Institute of Oncology (VHIO), has just demonstrated that it improves progression-free survival compared to its predecessor, fulvestrant.

These results were presented Thursday at the 45th edition of the Sant Antonio Breast Cancer Symposium. 2022 (SABCS), a symposium being held in Texas from December 6-10.

Breast cancer is the cancer most common cancer worldwide, with an estimated diagnosis of 2.3 million patients by 2020. Approximately 70% of breast cancer tumors are ER positive and HER2 negative. This type of cancer is usually treated with drugs that inhibit ER activity, which drives the growth of these tumors.

Fulvestrant is currently the only SERD drug (which is a type of selective estrogen receptor degrading drug) approved by the U.S. Food and Drug Administration (FDA) and by the European Medicines Agency (EMA) for the treatment of breast cancer, and must be administered via intramuscular injection in a physician’s office. Researchers are working to develop new SERDs that are more effective and easier to administer. Camizestrant, for example, is taken as a daily pill.

Mafalda Oliveira, a researcher in the breast cancer group at Vall d’Hebron Institute of Oncology (VHIO) and a medical oncologist at Vall d’Hebron Hospital, has been involved in the development of this molecule and is the international coordinator of the SERENA-2 study. “It is the first phase two trial investigating multiple doses of a next-generation SERD drug versus fulvestrant in postmenopausal women with advanced HER2-negative, HER2-positive breast cancer (ER) with recurrence o disease progression after receiving endocrine treatment,” Oliveira explains.

According to her, “the results of the study show that camizestrant is. statistically and clinically superior to fulvestrant in terms of increased progression-free survival,” which is the time from the start of treatment until the tumor grows back. In addition, this new drug also demonstrated a better disease control in patients with pulmonary or hepatic metastases.

“The results of this study support the continuation of the development of camizestrant in hormone receptor-positive breast cancer,” Oliveira points out. “These results are noteworthy and may revive enthusiasm for the development of oral SERDs in breast cancer,” he concludes.