New Clinical Trial Results for Palbociclib in Breast Cancer Treatment

Overview of the Clinical Trial

A recent study published in the New England Journal of Medicine evaluated the effectiveness of palbociclib in combination with standard breast cancer treatment. In the United States, around 266,000 new cases of breast cancer are anticipated this year, many of which are classified as hormone-receptor-positive (HR-positive). These types of cancers typically thrive on hormones such as estrogen.

Challenges of Hormone Therapy

Patients diagnosed with HR-positive breast cancer generally receive hormone therapy. However, some patients may develop resistance to these treatments, necessitating alternative options for those with advanced disease.

Mechanism of Action of Palbociclib

Palbociclib functions by inhibiting cyclin-dependent kinases, which are essential for cell division, thereby slowing cancer growth. An international research team conducted the phase-3 clinical trial known as PALOMA-3 to assess the efficacy of this drug in women with breast cancer.

Study Participants and Methodology

The trial involved 521 women diagnosed with metastatic, HR-positive breast cancer, all of whom had previously undergone hormone therapy but experienced disease progression. Participants were randomly assigned to receive either the standard treatment combined with palbociclib or the standard treatment along with a placebo.

Key Findings

The study revealed that palbociclib significantly improved overall survival rates. The median survival for patients receiving the standard treatment plus palbociclib was 34.9 months, compared to 28 months for those in the placebo group. Notably, even greater improvements were documented in patients who had previously shown favorable responses to hormone therapy.

Expert Commentary

Dr. Massimo Cristofanilli, the lead author of the study, remarked, “Typically, treatments for estrogen-positive metastatic breast cancer delay the progression of cancer but almost never prolong the life of patients. This treatment is the first of its kind to show such an important benefit. We now have solid data to suggest that this treatment [palbociclib] should be the new standard of care.”

Conclusion

The findings from the PALOMA-3 trial underscore the potential of palbociclib as a groundbreaking treatment option for patients with metastatic HR-positive breast cancer.

References

Turner NC, Slamon DJ, Ro I, et al. Overall survival with palbociclib and fulvestrant in advanced breast cancer. 2018. N Engl J Med DOI: 10.1056/NEJMoa1810527
Drug improves survival in metastatic breast cancer. https://www.eurekalert.org/pub_releases/2018-10/nu-dis102418.php