|The following article features coverage from the 2020 San Antonio Breast Cancer Symposium. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
The addition of ipatasertib to chemotherapy did not benefit patients with advanced triple-negative breast cancer (TNBC), showed the primary results from the phase 3 IPATunity130 trial Cohort A (ClinicalTrials.gov Identifier: NCT03337724). The trial results were presented at the 2020 Virtual San Antonio Breast Cancer Symposium (SABCS).
The trial enrolled 255 patients with locally advanced unresectable or metastatic TNBC whose tumors harbored at least 1 alteration in PIK3CA/AKT1 or PTEN. Eligible patients had not received chemotherapy for advanced TNBC. Patients were randomly assigned to receive treatment with ipatasertib plus chemotherapy or placebo plus chemotherapy.
Overall, about half of patients (51%) had PIK3CA/AKT1-activating mutations and half (49%) had PTEN alterations.
At a median follow-up of 8.3 months, patients on the ipatasertib arm had the same median progression-free survival as those on the placebo arm (7.4 vs 6.1 months, respectively) and risk of disease progression (hazard ratio, 1.02; 95% CI, 0.71-1.45; P =.9237).
The overall response rate was similar between the ipatasertib arm and placebo arm (39% vs 35%, respectively), as was the clinical benefit rate (47% vs 45%, respectively).
The frequency of serious adverse events was similar between the ipatasertib arm and placebo arm (19% vs 21%, respectively). Dose reductions due to adverse events were more commonly seen in the ipatasertib arm than the placebo arm (35% vs 14%, respectively). Diarrhea was considerably more common in the ipatasertib arm, affecting most patients.
Study presenter Rebecca Dent, MD, National Cancer Center, Singapore, noted that the results from this trial differ from findings in both randomized phase 2 trials of AKT inhibition in advanced TNBC, most notably the LOTUS trial looking at ipatasertib and the PAKT trial looking at capivasertib.
“Further analyses of IPATunity130 Cohort A are ongoing to explore potential biomarkers of benefit from ipatasertib.”
Disclosures: Dr Dent disclosed receiving honoraria from Roche and several other pharmaceutical companies. The trial was sponsored by Roche/Genentech. For a full list of disclosures, please refer to the presentation slides.
Read more of Cancer Therapy Advisor‘s coverage of the 2020 SABCS meeting by visiting the conference page.
Dent R, Kim S, Oliveira M, et al. Double-blind placebo (PBO)-controlled randomized phase III trial evaluating first-line ipatasertib (IPAT) combined with paclitaxel (PAC) for PIK3CA/AKT1/PTEN-altered locally advanced unresectable or metastatic triple-negative breast cancer (aTNBC): primary results from IPATunity130 Cohort A. Presented at: 2020 Virtual San Antonio Breast Cancer Symposium; December 8-11, 2020. Abstract GS3-04.