Patients with HER2 negative, hormonal receptor positive metastatic breast cancer experienced improved survival when treated with a combination of endocrine therapy and the new CDK-inhibitor, palbociclib. Results from a recent study, published in the Journal of Cell Physiology, suggest that palbociclib, in combination with either letrozole, an aromatase inhibitor, or fulvestrant, a selective estrogen receptor down-regulator, improves the so-called progression free survival in women with HR+HER2-metatastatic breast cancer by as much as 10 months when compared to endocrine therapy alone.
The study, “Palbociclib plus endocrine therapy in HER2 negative, hormonal receptor positive, advanced breast cancer. A real-world experience,” was conducted by a multidisciplinary Italian-American team with a long and productive history of collaboration with Prof. Antonio Giordano, M.D., Ph. D., Director of the Sbarro Institute for Cancer Research, and the Sbarro Health Research Organization, Temple University.
“Palbociclib is the first of a new class of drugs that work by inhibiting two crucial cell division proteins called CDK4 and CDK6,” explains Dr. Patrizia Vici, medical oncologist at the Division of Medical Oncology 2, IRCCS Regina Elena National Cancer Institute, Rome, Italy.
In the study, researchers focused on the use of Palbociclib in clinical practice, in order to collect data on the new drug’s efficacy and toxicity in support of evidence established from clinical trials.
“In this study, we sought confirmative evidence from the real world setting concerning the use of palbociclib in HR+HER2-metatastatic breast cancer,” says Dr. Maddalena Barba, researcher at the Regina Elena National Cancer Institute of Rome. “Clinical trial results do not always tell us everything we need to know for the clinical setting, because metastatic breast cancer patients are often heavily pre-treated, and may present related comorbidities.”
“When globally considered, these characteristics may be more often associated with less favorable outcomes,” says Barba.
“Overall, the evidence emerged from this cohort of Italian HR+HER2-metatastatic breast cancer patients, the largest ever treated with palbociclib in clinical practice so far, confirming the efficacy and toxicity data from the clinical trials,” explains Giordano, senior scientist and scientific advisor for the entire project.
“In addition, some intriguing findings have emerged from subgroup analyses showing less favorable outcomes in women pre-treated with the chemotherapy agent everolimus,” says Giordano. “This is a first time finding, which suggests the need for confirmation and further investigation of the underlying mechanisms in a future study.”