Frequently Asked Questions

What is the primary challenge in developing preclinical systems for in vivo CAR-T?

The central difficulty is creating a system that accurately recapitulates the human tumor microenvironment and the complex interactions with a functional immune system. Standard immunodeficient systems often fail to predict clinical outcomes related to cytokine release syndrome (CRS) or neurotoxicity.

Why are certain translationally relevant systems considered for in vivo CAR-T programs?

For specific applications, the immunological and physiological similarity of certain biological systems to humans provides more predictive data. This is particularly relevant for evaluating on-target, off-tumor toxicities and complex immune-mediated responses not observable in conventional systems.

How do you ensure system selection aligns with the therapeutic’s mechanism of action?

A tailored preclinical strategy is developed based on the asset’s specific attributes. This involves validating target antigen expression, determining optimal tumor engraftment kinetics, selecting appropriate host systems, and designing endpoints that reflect the CAR construct’s intended biological activity.

Additional Insights

Evaluating the efficacy of advanced therapeutics and complex biologics requires a departure from conventional preclinical templates. For in vivo CAR-T therapies, which reprogram the immune system directly within the patient, selecting or developing the correct in vivo system is a pivotal decision point. Applying proven intelligence in preclinical system development is required to accelerate these next-generation therapies toward IND submission.

A standard, one-size-fits-all testing approach does not exist for these modalities. The efficacy of an in vivo CAR-T therapy is dependent on successful vector delivery, target cell transduction, and CAR expression, followed by the expansion and persistence of the engineered T-cells. Off-the-shelf xenograft systems are often inadequate for capturing this multi-stage biological cascade.

Our approach is built on a science-based, data-driven preclinical strategy tailored to the asset. This process includes:

• Target & Host System Validation: We begin by confirming target antigen expression and selecting the appropriate host system, which may involve humanized or other specialized biological systems.
• Phase-Appropriate Assay Development: All immunogenicity and bioanalytical assays are developed and qualified under phase-appropriate GCLP guidelines to ensure data integrity for regulatory review.
• Customized Efficacy Endpoints: We design studies with endpoints that extend beyond simple tumor volume measurements to include CAR-T cell persistence, biodistribution, cytokine profiling, and detailed histopathology.

For programs requiring a more translationally relevant system, certain approaches offer significant advantages in de-risking clinical translation. Our team’s deep experience in long-term evaluations of AAV-delivered gene editing systems provides a strong foundation for assessing the durability and safety of other complex genetic therapies.

The core scientific team executing these programs maintained a 100% successful IND rate since 2019 in their prior roles, bringing that same rigor to Franklin Biolabs upon its launch in 2024. This allows for a deeper understanding of potential immune-mediated toxicities before first-in-human trials. By designing and executing studies that generate precise, reproducible data, we help sponsors minimize clinical risk and support programs on an 18-24 month timeline to IND.