The effect of these double mutations was also evident in a nucleotide exchange assay with both sotorasib and adagrasib. Here we could observe inhibition for KRAS(G12C/H95L) and KRAS(G12C/Y96D) with sotorasib, but with compromised affinity in comparison to KRAS(G12C) (Figure and Table ). Adagrasib showed negligible inhibition with KRAS(G12C/Y96D), but surprisingly retained some low-level functionality with KRAS(G12C/H95L) (Figure and Table ). Using KRAS(G12C/H95L), thermal stability increased with addition of 10 µM sotorasib, while adagrasib only modestly increased the stability of this mutant (Figure and Table ). With KRAS(G12C/Y96D), only 100 µM sotorasib yielded a measurable increase in thermal stability (Figure ). Although the nucleotide exchange and thermal stability results with KRAS(G12C/H95L) are not directly aligned, kinetic nucleotide exchange experiments indicate that sotarasib binds covalently to KRAS(G12C/H95L) (Figure ). Most likely, the weakened binding of adagrasib as a result of the H95L mutation is overrepresented in the thermal shift assay in comparison to results obtained in nucleotide exchange assay (Figure and).