The FDA's Guidance on bispecific antibodies: Pharma's concerns

By Dr Nicola Davies

Bispecific antibodies are artificial proteins that contain two different antigen-binding sites, allowing them to bind to two different types of antigens at the same time.1 As a result, bispecific antibodies can target several molecules, which potentially provides an advantage over utilizing combination therapies or mixtures of various antibodies, writes Dr Nicola Davies in her exclusive blog for The Pharma Letter. Therapeutic areas that could benefit from bispecific antibodies include cancer, infectious diseases, and inflammatory conditions.1

Examples of bispecific antibodies currently available in the US include Amgen’s Blincyto (blinatumomab) for treatment of Philadelphia chromosome-negative relapsed or refractory acute lymphoblastic leukemia and Roche’s Hemlibra (emicizumab-kxwh) for treatment of hemophilia A.2 Many other drug manufacturers are developing bispecific antibodies, but recent safety concerns have prompted action from the Food and Drug Administration. For example, the FDA issued a temporary hold when Xencor announced that two participants passed away from using one particular bispecific antibody in a Phase I clinical trial.2 This hold was lifted when the company agreed with the FDA to amend their study protocol to include additional safety monitoring parameters, such as the management of cytokine release syndrome.3