The Food and Drug Administration (FDA) has granted an accelerated approval to the frontline combination of Tecentriq (atezolizumab) plus Abraxane (nab-paclitaxel) for patients with unresectable locally advanced or metastatic PD-L1–positive triple-negative breast cancer (TNBC). The combination is the first cancer immunotherapy regimen approved for breast cancer.
The approval is based on the phase 3 IMpassion130 trial, in which the addition of the PD-L1 inhibitor Tecentriq to Abraxane reduced the risk of disease progression or death by 40 percent compared with Abraxane alone in this patient population.
The study evaluated the efficacy and safety of the PD-L1 inhibitor plus chemotherapy versus Abraxane alone in treatment-naïve patients with metastatic TNBC. Patients were randomized to receive Abraxane with Tecentriq (451 patients) or with placebo (451 patients). Treatment was given until disease progression or unacceptable toxicity.
The coprimary endpoints were progression-free survival (PFS) and overall survival (OS) in both the intent-to-treat (ITT) and PD-L1–positive populations; secondary endpoints were overall response rate, duration of response and safety. Patients were stratified by prior taxane use, liver metastases and PD-L1 expression, which was defined as at least 1 percent on tumor-infiltrating immune cells to be positive.
Results of the primary PFS analysis in the PD-L1–positive population demonstrated a clinically meaningful median PFS of 7.4 months with Tecentriq/Abraxane and 5 months with chemotherapy. The one-year PFS rates were 29 percent and 16 percent with Tecentriq/Abraxane and Abraxane, respectively.
In the ITT population, the median PFS with Tecentriq/Abraxane was 7.2 months compared with 5.5 months for Abraxane. Moreover, the one-year PFS rates were 24 percent in the combination arm and 18 percent in the Abraxane arm.
At a 12.9-month follow-up, an interim OS analysis of the PD-L1–positive population showed a clinically meaningful improvement with added Tecentriq at 25 months versus Abraxane alone at 15.5 months. Two-year OS rates were 54 percent and 37 percent in the immunotherapy/chemotherapy and chemotherapy arms, respectively.
Regarding safety, most all-grade side effects were similar between arms. The most common grade 3/4 side effects with Tecentriq/Abraxane and Abraxane were neutropenia, decreased neutrophil count, peripheral neuropathy, fatigue and anemia.
This article originally appeared on OncLive, as “FDA Approves Atezolizumab Combo for Frontline TNBC”