Dana-Farber's Erica Mayer, MD, MPH discusses the final analysis of the International Phase 3 PALLAS clinical trial presented at the 2021 San Antonio Breast Cancer Symposium.
America Mayor from Dana Farmer and today at SAn Antonio we are presenting updates on the Palace trial. Palace is a global randomized phase three trial which has been exploring the agent Pappas I clip, which is a c d k 46 inhibitor using it in combination with adjuvant endocrine therapy for patients with Stage two and three hormone receptor positive, her two negative breast cancer. The palace trial randomized over 5700 patients around the world to receive either pelvis cyclops for a plan of two years with ongoing adjuvant endocrine therapy versus adjuvant endocrine therapy alone. This is a global effort that is co led by the Alliance Foundation in the United States and the Austrian breast cancer study group in Vienna and it's a wonderful global study. We are presenting final analysis, a preplanned protocol final analysis. Um this is being presented by my colleague Michael Tennant on behalf of the Palace investigators. Um in this final analysis we are showing outcomes in the 5700 patients And this is an update from a previous interim analysis which was presented about a year and a half ago. In our analysis, we show that with longer term follow up, which is 31 months of follow up, there were no new safety signals seen in the study and in terms of our primary endpoint of invasive disease free survival, there was not a difference between the two arms with the patients who have received Calvin cycle of having an I. D. F. S of 84.2% versus 85.4% in the patients receiving endocrine therapy alone. In subgroup analysis, there was not a specific subgroup which appeared to derive either more or less benefit from the addition of how the cyclist we monitored discontinuation is carefully in the palace trial and the majority of these were due to toxicity. Um We did find though that there was no signal that patients who um stopped pelvis cyclops early or had a lower dose intensity um had a differential outcome in terms of more or less benefit from the addition of the C. D. K. 46 inhibitor. Um We uh we also are presenting some additional data um from our quality of life analysis in Palace. This was a parallel part of Palace research where all patients in the study completed quality of life surveys every three months while they were receiving treatment. What we found was that there was no significant difference in quality of life between the patients receiving the combination treatment with tablets. I club and endocrine therapy versus those receiving endocrine therapy alone. Importantly, we wanted to focus on some of the side effects which can be associated with Cd K 46 inhibitors such as fatigue. And reassuringly we did not see a substantial detriment in patient reported fatigue and those receiving pelvis cyclops versus those who did not. We're also presenting data on patient level adherence. We did a very robust analysis of patients reporting of their taking their drugs. This was through um pill counts drug diaries and some very specific questionnaires related to adherence. What we found was that in the patients who were told to take their medications either endocrine therapy or study therapy, Patients were extremely good at taking their medicines with rates of adherence of greater than 95%. Importantly, we also did not see that patients taking, how the cyclops had any difficulty taking endocrine therapy. All of these patients were taking their endocrine therapy properly, which is incredibly important in a hormone receptor positive survivorship population. Moving on from these presentations, the Palace trial collected very large numbers of tissue and blood samples as part of our Trans Palace program translational Palace program and this is also a global collaborative effort where we are analyzing all of the tissue and blood samples and we hope in the years to come we are going to be able to present a tremendous amount of data not only related to biomarkers for CTK 46 inhibitors, but also in terms of the general biology of hormone receptor positive breast cancer and the experience of taking adjuvant endocrine therapy. So I hope you have a chance to look at our posters and watch our presentation and enjoy SAN Antonio breast cancer symposium. Thank you
