IPATunity130 Trial of Ipatasertib Plus Paclitaxel for Advanced Triple-Negative Breast Cancer
Posted: Tuesday, January 19, 2021
In the phase II LOTUS trial, patients with PIK3CA-, AKT1-, or PTEN-altered locally advanced unresectable or metastatic triple-negative breast cancer appeared to derive a progression-free survival benefit from treatment with the AKT inhibitor ipatasertib in combination with paclitaxel; however, according to Rebecca Dent, MD, of the National Cancer Center, Singapore, and colleagues, this did not seem to hold true in the phase III IPATunity130 trial. Primary results from cohort A were presented during the virtual 2020 San Antonio Breast Cancer Symposium (SABCS; Abstract GS3-04).
A total of 255 patients were randomly assigned in a 2:1 ratio to receive paclitaxel in combination with either ipatasertib or a placebo. The progression-free survival rate was 55% with both ipatasertib and the placebo (median 7.4 vs. 6.1 months; P = .9237). The objective response rate was 39% with ipatasertib and 35% with the placebo. The study remains immature for overall survival analysis; deaths were reported in 20% of patients.
Adverse events of grade 3 or higher (46% vs. 44%), fatal adverse events (both 1%), and adverse events leading to treatment discontinuation (14% vs. 15%) occurred at similar rates with ipatasertib and the placebo. However, adverse events leading to dose reduction of any treatment were observed more frequently with ipatasertib than with placebo (35% vs. 14%). Diarrhea (80% vs. 31%), alopecia (46% vs. 44%), and nausea (36% vs. 23%) were among the most commonly reported adverse events. The safety profile of this combination appeared to be congruent with previous reports.
“Biomarker analyses are ongoing to evaluate the potential markers of ipatasertib benefit,” the investigators concluded.
Disclosure: For full disclosures of the study authors, visit sabcs.org.
