Recent developments and future clinical prospects of polyclonal antibody therapies

The antibody therapeutic landscape has been dominated by monoclonal antibodies (mAbs) since the early 2000s, leading to polyclonal antibodies (pAbs) assuming a less prominent role in clinical use. However, the multiepitope targeting capability of pAbs has generated renewed interest over the last five years. Emerging technologies such as recombinant antibody pools are prompting a revisit of the distinction between traditional mAb and pAb therapies.

Using listed FDA-approved polyclonal therapies as a basis for our literature searches, we explore the applications of current pAb therapies and examine whether mAbs may eventually replace them. We also discuss the costs and cost-effectiveness of directly competing mAb and pAb therapies for a variety of clinical indications. Finally, we review emerging technologies, such as glyco-humanized and recombinant pAbs, covering their modes of action, manufacturing approaches, and current clinical trial statuses.

The current clinical pAb therapy landscape is varied, evolving, and continues to be challenged by mAbs. For the pAb therapies explored in this review, multiple competing mAb alternatives are progressing toward clinical approval. Future hybrid technologies like recombinant pAbs may allow multiple epitope targeting while achieving enhanced safety profiles and batch-to-batch consistency; however, their cost-effectiveness remains uncertain.