Antibody Structure and Remaining Mechanistic Questions

Dr Whitman raises a further structural distinction, noting that cosibelimab retains an active Fc domain capable of mediating antibody-dependent cellular cytotoxicity. The faculty explore what this means at the level of antibody engineering, contrasting it with agents designed to minimize Fc effector function, and consider whether ADCC could contribute meaningfully to antitumor activity in cutaneous squamous cell carcinoma. Dr In offers a measured view, characterizing the mechanism as biologically interesting and hypothesis-generating rather than clinically proven, and cautioning that no data currently link Fc activity to improved outcomes in this disease. Both faculty stress the absence of head-to-head randomized comparisons among the three approved agents, which leaves mechanism-based reasoning as an incomplete guide to selection. They close by affirming that all three checkpoint inhibitors represent reasonable options, with the choice appropriately driven by individual patient characteristics rather than mechanistic preference.