Pathology Matters, part 1 of a 3 part series: Preclinical Studies and Histopathology

June 12, 2017

The histopathology evaluation in preclinical studies is performed to support the study objectives. The study type, tissues examined, and intended data use all determine what pathology analysis is needed. Here we review the preclinical studies that rely heavily on histopathology data.

Histopathology is a key component of these preclinical study types:

  • Device safety studies
  • Biocompatibility studies
  • Systemic toxicity studies

These studies differ in the types of tissues evaluated and the criteria applied to the pathology analysis. How does histopathology help support the goals for each of these study types?

Safety studies for both implantable and interventional devices evaluate local and distant effects on the host and may also assess host-derived impacts on an implanted device. The histopathology goal is to uncover potential safety concerns and provide support for clinical trial or licensing applications. If the preclinical model adequately mimics a clinical application, these studies may also demonstrate device efficacy.

Biocompatibility studies use standardized protocols to assess the local host response to subcutaneous or intramuscular implanted devices. Histopathology evaluation of the degree and type of host response to the implant is assessed relative to a predicate device or standard control implant.

Systemic toxicity studies use histopathology to evaluate organs and tissues for evidence of deleterious effects following host exposure to device components or drugs. With careful study design, systemic toxicity studies may be combined with implantable device biocompatibility studies in small animal models.

These general classifications apply to studies ranging from post benchtop feasibility investigations to formal regulatory submissions and the required histopathology depends on both the study type and the intended data use. In the next installment of this series, we examine in more detail the different types of histopathology evaluations performed for preclinical studies.