The ESMO Virtual Plenary, which takes place on July 15 and 16, has become the innovative setting for the presentation of the Keynote-522 study. Dr. Javier Cortés, director of the IBCC, is one of the creators and co-authors of this study.
The unpublished results of the international trial Keynote-522 have been presented for the first time in the new virtual plenary session format at the ESMO (European Society for Medical Oncology) congress, which takes place on July 15 and 16. Dr. Javier Cortés, director of the International Breast Cancer Center (IBCC), is one of its creators and co-authors.
The Keynote-522 study has demonstrated for the first time a lower recurrence of triple-negative breast cancer (TNBC), the most aggressive breast tumour, with the use of neoadjuvant and adjuvant pembrolizumab, in addition to the standard chemotherapy and surgery regimen, in stages II and III of these tumours.
”This is a very important study, as it demonstrates for the first time that immunotherapy decreases the chances of the tumour reoccurring in patients with early-stage triple-negative breast cancer, which probably translates into a greater number of patients being cured,” says Dr. Javier Cortés.
This randomized phase III clinical trial was conducted in 181 centres in 21 countries, and included 1,174 patients with stage II and III triple-negative breast cancer who had not received any prior treatment for this disease. Patients were randomized in a 2:1 ratio to receive treatment with preoperative chemotherapy and pembrolizumab (784 patients) or preoperative chemotherapy and placebo (390 patients). After surgery, patients received nine additional courses of pembrolizumab or placebo. The primary endpoints of the study were pathological response rate and event-free survival (EFS).
Previously, in December 2019, the results for the first primary endpoint were published; the patients treated with pembrolizumab had a higher pathological complete response rate.
Regarding the second and most important primary endpoint, at 36 months of follow-up, patients in the pembrolizumab group had 15.7% of disease recurrence events compared to 23.8% among those in the placebo group, i.e. in the pembrolizumab group there were 8.1% fewer recurrence events, a statistically significant difference, according to the authors of the study. This data implies that the EFS rate was 84.5% for patients in the pembrolizumab group compared to 76.8% in patients assigned to the placebo group at this follow-up stage.