Atezolizumab (in Combination with Nab-Paclitaxel): A Review in Advanced Triple-Negative Breast Cancer

Atezolizumab (Tecentriq®), an immune checkpoint inhibitor against programmed death ligand 1 (PD-L1), is the first immunotherapy agent to be approved (for use in combination with nab-paclitaxel) in the USA, the EU (as first-line) and Japan for the treatment of advanced triple-negative breast cancer (TNBC). Approval was based on the results of the phase III IMpassion130 trial in patients with unresectable locally advanced or metastatic TNBC, in which atezolizumab plus nab-paclitaxel significantly prolonged progression-free survival (PFS) when compared to placebo plus nab-paclitaxel in the intent-to-treat (ITT) population and the PD-L1+ subgroup. Statistically significant overall survival (OS) benefits were not seen in two interim analyses and final OS data are awaited. The tolerability and safety profile of atezolizumab plus nab-paclitaxel was consistent with those of each individual drug. The most common treatment-related adverse events included neutropenia, peripheral neuropathy and reduced neutrophil count. Adverse events of special interest occurred with higher frequency in patients who received atezolizumab plus nab-paclitaxel than placebo plus nab-paclitaxel, and were mostly immune-related (e.g. immune-related rash, hypothyroidism and hepatitis). Health-related quality of life was not significantly impacted by the addition of atezolizumab to nab-paclitaxel therapy. Thus, atezolizumab plus nab-paclitaxel is a useful immunochemotherapy option for patients with unresectable locally advanced or metastatic TNBC, including those whose tumours have PD-L1 expression ≥ 1%.