Table 1.

Characteristics of anti-CD20 mAbs

Generation	Format	Drug	Special features	FDA-approved indications
1st	Murine–human chimeric	Rituximab	Immunogenicity occurs due to chimeric nature	NHL, CLL, RA, GPA, MPA
2nd	Humanized	Ocrelizumab	Binds an overlapping epitope region as rituximab. Increased binding affinity. Enhanced ADCC and less CDC compared to rituximab [8, 32]	RRMS and PPMS
		Veltuzumab	Complementarity-determining regions are similar to rituximab. Greater binding avidity and effect on CDC than rituximab [8]	Orphan status designation for ITP and pemphigus
		Obinutuzumab	Binds to an epitope on CD20 that partially overlaps with that of rituximab. Greater ADCC than rituximab. Unlike rituximab, obinutuzumab does not stabilize CD20 in lipid rafts and thus has less CDC. More effective at direct B cell apoptosis [63]	With chlorambucil for previously untreated CLL
	Fully human	Ofatumumab	Binds to an epitope distinct from that recognized by rituximab, ocrelizumab, veltuzumab, and obinutuzumab. Greater CDC and apoptosis than rituximab [17]	Refractory or conventional therapy-intolerant CLL