Dr Yuan Yuan on Oral Ipatasertib's Potential in mTNB

Yuan Yuan, MD, PhD, medical oncologist at City of Hope, discusses an ongoing study on ipatasertib with chemotherapy and atezolizumab presented at the San Antonio Breast Cancer Symposium 2020.

Novel oral drugs have been in the spotlight in light of the pandemic, and an ongoing trial at City of Hope aims to assess the safety and efficacy of a combination of oral ipatasertib, oral chemotherapy, and IV atezolizumab in the treatment of metastatic triple-negative breast cancer. Yuan Yuan, MD, PhD, associate professor in the Department of Medical Oncology and Therapeutics Research at City of Hope, discusses the ongoing trial, which is being presented at the 2020 San Antonio Breast Cancer Symposium.


Your poster presentation is a study of ipatasertib with chemotherapy and atezolizumab in mTNBC. What do you expect to see as the trial goes on?

So we started off the preclinical study. We tested the combination of carboplatin, which is our chemotherapy backbone in our trial. We started off the cell lines, we did mice models, so we did preclinical experiments before launching the phase I trial. In our study we had clearly showed synergy between carboplatin and ipatasertib, so our preclinical observations are very promising, especially PIK3CA-mutated tumors.

Currently, our trial is still ongoing. We have a total accrual goal of 40 patients, and this morning I actually got a summary that about 24 patients are being treated so far. We're still a bit early in evaluating the response rate, so hopefully by sometime next year, we'll have the results. Now, safety is a major focus of this phase I trial. We have not observed any concerning safety signals, so the good news is that the combination appears to be very well tolerated.

In the current clinical trial, we have 3 arms. Arm 1 is combining carboplatin with paclitaxel plus ipatasertib. Now, arm 2 is combining carboplatin alone with ipatasertib. Arm 3 is of strong interest, because we have now adopted adjuvant capecitabine as a standard care for patients who underwent neoadjuvant chemotherapy for newly diagnosed, early-stage, triple-negative breast cancer who did not achieve complete response after standard care chemotherapy. And if they have residual cancer, they're now a standard of care, which is offering a capecitabine for a total of 6 months or course of therapy.

Our study is really designed to understand is it safe to combine capecitabine, which is oral chemo—pretty old, but very effective—with oral ipatasertib and IV immune checkpoint inhibitor atezolizumab. So the whole idea is that we are adding the 2 oral agents, and then we can on top of that add an immune checkpoint inhibitor. So currently, we have enrolled 4 or 5 patients so far. Safety is pretty well tolerated, and it is too early for efficacy analysis. We're looking forward to identifying activity. Hopefully by sometime next year, we'll have the answer.