Subcutaneous Atezolizumab: A Jab Without a Benefit.

Alternative dosing regimens for atezolizumab: right dose, wrong frequency. In a similar approach our group took for reoptimizing nivolumab and pembrolizumab, dose regimen simulation12 is the initial step to identify potential modified regimens, which can then be evaluated prospectively in a clinical trial,13 aiming to achieve the therapeutic concentration identified by Genentech. The recent publication by Felip et al1 describing the dose optimization of subcutaneous atezolizumab concerns us due to the continued missed opportunity to lower an unnecessarily high atezolizumab dose.2 Felip et al cite the 2016 article by Genentech authors that identified a target clinical serum concentration of 6 g/mL (4 g/mL without bevacizumab).3 Yet at the currently approved intravenous dose of 1200 mg every 3 weeks (equivalent to 15 mg/kg every 3 weeks), the steady-state trough concentration is approximately 140 g/mL, which is >20-fold higher than the stated target trough of 6 g/mL.4 Furthermore, doses as low as 1 mg/kg have been demonstrated to have clinical activity.5,6 Calls for dose reoptimization are not limited to individuals or small groups. [Extracted from the article]