In vitro comparison of CD20xCD3 biosimilar antibodies against diffuse large B cell lymphoma (DLBCL) cell lines with different levels of expression of CD20

<p dir="ltr">Although CD20xCD3 bispecific antibodies (BsAbs) have demonstrated transformational activity in<br>DLBCL, some patients fail to respond and others relapse. To begin to explore possible limitations we<br>compared the in vitro activity of four CD20xCD3 biosimilar BsAbs against four DLBCL cell lines with<br>CD20 expression ranging over a hundred-fold. All four biosimilar BsAbs demonstrated superior in<br>vitro activity to rituximab, with biosimilar glofitamab consistently being the most potent. Moreover,<br>biosimilar glofitamab and odronextamab retained significant activity in the presence of low-level<br>CD20 expression. Finally, one DLBCL cell line exhibited intrinsic resistance to all four CD20xCD3<br>BsAbs despite inducing marked T-cell and NK cell activation.