Puma neratinib meaningful cuts recurrence risk, ups survival in early stage breast cancer

 

• Puma Biotechnology (NASDAQ:PBYI) jumps 9% after-hours after presenting efficacy results of neratinib in HER2-positive early stage breast cancer (eBC) from the Phase III ExteNET trial at the 2020 Virtual San Antonio Breast Cancer Symposium.
• The trial included 2,840 patients who received neratinib after neoadjuvant and/or adjuvant therapy with chemotherapy and trastuzumab. The primary endpoint was invasive disease-free survival (iDFS). Secondary endpoints include overall survival and cumulative incidence of CNS metastases.
• In the ITT population, 127 of 1420 patients (8.9%) in the neratinib group and 137 of 1420 patients (9.6%) in the placebo group died, as of the analysis cut-off date (July 2019).
• The estimated 8-year overall survival (OS) rates were 90.1% in the neratinib group and 90.2% in the placebo group (stratified HR 0.95; 95% confidence interval [CI] 0.75-1.21; p=0.69).
• The cumulative incidence of CNS metastases at 5 years was 1.3% (95% CI 0.8-2.1) in the neratinib arm and 1.8% (95% CI 1.2-2.7%) in the placebo arm, while the estimated CNS disease free survival (DFS) at 5 years was 97.5% in the neratinib group and 96.4% in the placebo group (stratified HR 0.73; 95% CI 0.45-1.17).
• In the HR+ /< 1 yr patient population, 53 of 670 patients (7.9%) in the neratinib group and 68 of 664 patients (10.2%) in the placebo group died.
• The estimated 8-year OS rates were 91.5% in the neratinib group and 89.4% in the placebo group, corresponding to a 2.1% absolute benefit.
• The cumulative incidence of CNS metastases at 5 years was 0.7% (95% CI 0.2-1.7) in the neratinib arm and 2.1% (95% CI 1.1-3.5) in the placebo arm, while the estimated CNS DFS was 98.4% in the neratinib group and 95.7% in the placebo group.
• In the HR+/ <1 yr, no pCR subgroup of patients (n=295), 8-year OS rates were 91.3% in the neratinib group and 82.2% in the placebo group, corresponding to a 9.1% absolute benefit.
• In the HR+/ <1 yr, with a pCR (n=38), 8-year OS rates were 93.3% in the neratinib group and 73.7% in the placebo group, corresponding to a 19.6% absolute benefit.
• The cumulative incidence of CNS metastases at 5 years was 0.8% in the neratinib arm and 3.6% in the placebo arm, while the estimated CNS DFS at 5 years was 98.4% in the neratinib group and 92.0% in the placebo group.
• https://seekingalpha.com/news/3643164-puma-bios-neratinib-meaningful-reduces-risk-of-recurrence-and-improves-survial-in-early-stage