Sayeh Lavasani, MD of UCI Health gives an Update in Breast Cancer at MOASC’s Spotlight on Oncology
NATALEE’s study focused on comparing adjuvant ribocyclib plus a non-steroidal AI versus an AI alone in high-risk, early-stage, hormone receptor-positive breast cancer patients. The ribocyclib was administered at a lower dose of 400 milligrams daily for three weeks on and one week off, over three years. This study showed improvements in invasive disease-free survival, as well as trends towards enhanced overall survival in a three-year follow-up. These findings suggest an additional treatment option to reduce the risk of recurrence in earlier-stage hormone-positive breast cancer patients.
The study’s inclusivity criteria, encompassing hormone-positive stage two and three breast cancer patients, played a notable role in its success. By using a lower ribocyclib dosage, the study achieved both efficacy and tolerability, offering insights into the manageable side effects of a three-year adjuvant treatment regimen. This stands in contrast to historical studies employing higher dosages, which yielded more significant side effects.
Insights from the SONIA Trial: Tailoring CDK4/6 Inhibitor Use
The SONIA trial, conducted in the Netherlands, aimed to compare hormone receptor-positive metastatic breast cancer patients receiving AI as first-line therapy with or without a CDK4/6 inhibitor. Patients switched to fulvestrant (Faslodex) alone if they initially received a CDK4/6 inhibitor, or to fulvestrant combined with the inhibitor if they initially received AI alone. The study evaluated progression-free survival (PFS) after two lines of treatment and overall survival.
Results demonstrated no PFS difference between patients receiving a CDK4/6 inhibitor as first or second-line treatment. This suggests the potential for avoiding excessive CDK4/6 inhibitor usage and associated toxicities in metastatic hormone-positive breast cancer patients.
However, it’s important to note that the majority of patients in this trial received palbociclib, a CDK4/6 inhibitor with no overall survival benefit. Additionally, the choice of second-line Faslodex alone could be influenced by the evolving landscape of treatment options for metastatic breast cancer patients based on genomic profiles.
Insights from the PHERGain Trial: Personalizing Neoadjuvant Treatment for HER2-Positive Breast Cancer
The PHERGain trial focused on HER2-positive breast cancer patients in the neoadjuvant setting. Patients were randomized to standard TCHP chemotherapy plus HER2-directed therapy or HP (Herceptin + Pertuzumab) therapy for two cycles, followed by a PET scan to predict pathological complete response (pCR) risk. Patients not showing a positive response in the PET scan switched to chemotherapy.
The study showcased the potential to avoid chemotherapy for around one-third of HER2-positive patients using PET scan-based predictions of pCR. Notably, HP therapy alone achieved a substantial pCR rate of nearly 38-39%, with three-year invasive disease-free survival rates reaching around 96%. Those achieving pCR with HP alone experienced an impressive 99% invasive disease-free survival rate.
These findings emphasize the significance of personalized approaches in the neoadjuvant treatment of HER2-positive breast cancer patients, with the potential to minimize unnecessary chemotherapy while achieving excellent outcomes.