“There is a clear suggestion from SERENA-2 that camizestrant might be a better treatment than fulvestrant,” said press briefing moderator Carlos L. Arteaga, MD, Director of the Simmons Comprehensive Cancer Center and Associate Dean of Oncology Programs at UT Southwestern Medical Center, Dallas. “As it applies to ESR1 mutations, it appears to be better than fulvestrant at reducing the mutation levels in patients’ plasma. And that squares with preclinical studies, which had suggested these ESR1 mutations may respond better to these new SERDs [selective estrogen receptor degraders].... This is a small study, but the direction seems to be consistent with what the science has told us.”

Carlos L. Arteaga, MD

William Sikov, MD

Breast medical oncologist William Sikov, MD, said he is interested in seeing how camizestrant and other oral SERDs will stack up to fulvestrant when given in combination with cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors. Dr. Sikov is based at the Breast Health Center of Women and Infants Hospital of Rhode Island, and is a Professor of Medicine, Obstetrics and Gynecology at the Warren Alpert Medical School of Brown University.

“Fulvestrant is certainly a useful drug. Aside from the inconvenience and discomfort of the monthly injections, the side-effect profile is favorable,” Dr. Sikov noted. “When it is given with a CDK4/6 inhibitor, especially to patients who recurred on an aromatase inhibitor, it can be especially useful in terms of prolonging the duration of response. Studies are just now beginning to look at these combinations with the oral SERDs. If the oral SERDs are better than fulvestrant overall and in the subpopulation of patient in whom an ESR1 mutation has arisen, then they are probably also going to be better in combination with CDK4/6 inhibitors in patients who have progressed or recurred on an aromatase inhibitor.” 

DISCLOSURE: Dr. Arteaga has served as a scientific advisor for Novartis, Lilly, Merck, AstraZeneca, Daiichi Sankyo, OrigiMed, Immunomedics, Arvinas, Puma Biotech-nology, Athenex, Taiho Oncology, and Sanofi and holds stock in Provista. Dr. Sikov serves on the speakers bureau for Lilly Oncology, Seagen, and Daiichi Sankyo/AstraZeneca.