Selectivity of your compounds can be quantified by calculation of the selectivity entropies. Selectivity entropies are calculated from the percent inhibition values and measured IC50 values (Uitdehaag and Zaman, 2011). Selectivity entropy is a quantitative, single-value expression of the selectivity of compounds. It allows comparison of relative selectivity based on data from large pharmacological profiling experiments. Selectivity entropy is expressed as Ssel. The lower this value, the more selective a compound.
Uitdehaag et al. (2019) provides examples of the implications of quantifying selectivity, for instance, for the BTK inhibitors acalabrutinib and ibrutinib. Acalabrutinib is the most selective of the two inhibitors, with Ssel = 1.4 for acalabrutinib and Ssel = 2.4 for ibrutinib. This is also reflected in its cell panel profile. Acalabrutinib only inhibits one cell line, whereas ibrutinib inhibits the proliferation of eight cell lines. MEK inhibitor cobimetinib was shown to have a very low selectivity entropy (Ssel = 0.8), which was explained by its selectivity for MEK1 and MEK2, with only additional activity on MEKK1. This is due to its unique type III allosteric binding mode, which it shares with trametinib. Both drugs partially inhibit BRAF and RAF1 at 1 mmol/L, which could contribute to their efficacy.