Lapatinib is a reversible, dual inhibitor of EGFR/HER2 while the others are irreversible, pan-HER TKIs, so they should be more potent (more complete and sustained inhibition), but also with more/higher grade AEs I expect. It is not yet known which is the more potent, selective, less toxic agent plus there's the question of the best combo and in which patient populations. For instance, one combo Puma is testing (and Boehringer is not), is with Torisel, which make a lot of scientific sense but you never know if for real plus it could be too toxic.