Extracellular Vesicle Product Developer Creates Potency Assay

Developing potency assays for complex biologics, such as extracellular vesicle (EV)-based products, can be challenging for manufacturers, often delayed until regulators inquire further. Evox Therapeutics, however, has developed a potency assay that can potentially be adapted for multiple future products in their pipeline. Rebecca Gavin, PhD, chemistry, manufacturing, and controls (CMC) director at Evox, revealed that the assay has already been pre-qualified and transferred into a quality control (QC) laboratory, with the hope of full qualification during an upcoming first-in-human study next year.

This achievement, Gavin says, is a testament to the company's complexity, as CMC aspects are often postponed due to funding concerns. Evox's product encapsulates a ribonucleoprotein (RNP) within an EV, utilized as the delivery mechanism. The RNP is linked to a guide RNA, targeting a specific gene to reduce protein production. While this approach may raise complex questions about EV uptake and editing machinery reaching the nucleus, Gavin emphasizes that focusing on potency measurement can prevent over-characterization and over-testing.

To achieve this, the company developed an assay that measures the potency of EV products, demonstrating successful assembly and delivery to a cell. EV products are dosed at various concentrations on an adherent cell line, with cell lysates tested on a Jess Simple Western system to create a dose-response curve showing the product's effectiveness in reducing the target protein.

Evox plans to fully qualify this simple potency assay for commercial production and intends to adapt it for other products in their pipeline.