A major technical advancement in 2025 is the hybridization of in vivo and in vitro models through PDX-derived Organoids (PDXOs). While traditional Patient-Derived Xenografts (PDX) remain the gold standard for mirroring tumor heterogeneity, they are often limited by long gestation periods (2–8 months) and high costs. PDXOs solve this by taking low-passage tissue from a PDX model and expanding it into a 3D organoid culture in vitro.

This "best of both worlds" approach allows for high-throughput drug screening on a platform that retains the complex genetic architecture of a pre-treated patient tumor. These models are particularly effective for testing multispecific antibodies and Antibody-Drug Conjugates (ADCs). Technical insights into the "Matrix-Free" culture techniques that eliminate drug diffusion artifacts can be found in the Preclinical CRO Market research. By running massive parallel screens on PDXOs before moving to the final in vivo validation, CROs are shortening the oncology discovery timeline from months to weeks.