Gunter von Minckwitz, MD, PhD, Chairman, German Breast Group, Professor of Gynecology, University of Frankfurt, Germany, discusses the rationale behind the phase III PENELOPE trial.
It has been known for a while that patients who do not reach pathologic complete response (pCR) after neoadjuvant chemotherapy have a worse prognosis compared with those who do achieve pCR.
The NATAN study had investigated the use of a bisphosphonate in this setting, though improvement in event-free survival could not be achieved. This further proved the need for new treatment options.
Upon the announcement of progression-free survival benefit in a phase II study of palbociclib plus letrozole, von Minckwitz says oncologists believed the combination should be moved to an early disease setting. A conclusion was then reached to identify patients who have not achieved pCR to be candidates for a “post-neoadjuvant” study investigating palbociclib.