Phage-derived anti-idiotype and anti-YTE antibodies in development of MK-1654 pharmacokinetic and immune response assays.

MK-1654 is a fully human monoclonal antibody with YTE mutations currently in phase III clinical trials for prophylactic use in protecting infants from human respiratory syncytial virus infection. We generated anti-idiotype (anti-ID) and anti-YTE antibodies against MK-1654 by panning with MorphoSys HuCal phage libraries, and used the antibodies in the development of MK-1654 pharmacokinetic (PK) and immune response (IR) assays. Detection of MK-1654 in nonhuman primate and human nasal wash samples showed combined use of anti-ID and anti-YTE antibodies can deliver desired sensitivity and accuracy in PK studies. IR studies showed anti-ID can serve as suitable positive control in neutralizing antibody assays. Phage-derived anti-IDs and anti-YTEs are suitable for PK and IR assays.