Atezolizumab Plus Chemotherapy Improves Responses in Triple-Negative Breast Cancer

A statistically significant and clinically meaningful improvement in pathological complete response (pCR) was achieved with the combination of the monoclonal antibody atezolizumab (Tecentriq) plus albumin-bound paclitaxel (nab-paclitaxel; Abraxane), followed by doxorubicin and cyclophosphamide, when administered to patients with triple-negative breast cancer (TNBC), regardless of PD-L1 expression, compared with chemotherapy alone. With this result, the primary end point of the phase 3 IMpassion031 study was met, announced Genentech.

“Triple-negative breast cancer remains an aggressive disease with high rates of recurrence,” said Levi Garraway, MD, PhD, chief medical officer and head of Global Product Development, Genentech. “Our goal in treating TNBC at its earliest stages is to provide people with the best chance for a future cure. Adding Tecentriq to chemotherapy now has the potential to help women with TNBC at multiple different stages of the disease.”

Among the patients who received neoadjuvant atezolizumab in the study, high evidence of tumor tissue detectability at the time of surgery was observed, regardless of PD-L1 expression, compared with the chemotherapy arm. The safety of the combination observed in the study was consistent with the known profiles of each drug with no new safety signals.

The detailed results from IMpassion031 will be presented at an upcoming meeting and discussed with the FDA and the European Medicines Agency.

The multicenter, randomized, double-blind clinical trial is evaluating the efficacy and safety of atezolizumab plus chemotherapy compared with placebo plus chemotherapy. In the experimental arm, atezolizumab 840 mg is administered to patients via intravenous (IV) infusion every week for 12 weeks followed by atezolizumab combined with doxorubicin 60 mg/m² and cyclophosphamide 600 mg/m² every 2 weeks via IV infusions along with 4 doses of filgrastim (Neupogen) and pegfilgrastim (Neulasta) supportive therapy. Patients in the control arm are given matched placebo and matched chemotherapy/supportive therapy.

The secondary end points of the study include event-free survival (EFS) in all patients, EFS in the PD-L1-positive subgroup, disease-free survival in the overall population, disease-free survival in the PD-L1-positive subgroup, overall survival (OS), OS in the PD-L1-positive subgroup, changes from baseline, the percentage of patients who experience adverse events, serum concentration of atezolizumab, and the percentage of participants with snit-drug antibodies to atezolizumab.

The study population includes treatment-naïve patients with TNBC who had histologically document disease, an ECOG performance status of 0 or 1, primary tumor size greater than 2 cm by radiographic or clinical measurement, and those with adequate hematologic and end-organ function. At presentation, patients are required to be stage cT2-cT4, cN0-cN3, or cM0.

In addition to the IMpassion031 trial, atezolizumab is being evaluated in multiple phase 3 clinical trials. The ongoing studies are in lung, genitourinary, skin, breast, gastrointestinal, gynecological, and head and neck cancers. In these studies, atezolizumab is being investigated as a single agent and in combination regimens.

_Reference:

_{Genentech’s Tecentriq in combination with chemotherapy (including abraxane) meets primary endpoint of improved pathological complete response, regardless of pd-l1 status, as initial treatment for people with early triple-negative breast cancer. News release. Genentech. June 18, 2020. Accessed June 18, 2020. https://bwnews.pr/3ehYynM.}