When tracking lesions in a dermatology clinical trial, objective, reproducible methods and measurable treatment progress should inform endpoints and outcomes. However, much of dermatology endpoint data comes from the investigators’ visual descriptions of their observations, making objective assessments challenging. Even the most skilled and trained dermatologists may struggle with tracking lesions consistently and objectively between patients, and between the same patient at different times.
The diversity of dermatological illnesses, symptoms, and their causes further complicates data evaluation in clinical trials. Regulatory guidelines provide little consensus on the definition of study endpoints, or on the technologies used to track lesions in trials.
At Novella Clinical, we recommend sponsors overcome these challenges by incorporating some of the many tools and technologies available to track lesions objectively and consistently.
Describing lesions consistently
Consistent language is a crucial tool to help researchers standardize clinical trial data. The International League of Dermatological Societies’ (ILDS) glossary of dermatology lesions, updated in 2016, provides a common lexicon for defining lesions. Containing definitions for 13 basic terms and more than 100 additional terms, with a clinical example for each term, the glossary’s unifying language was created through a consensus of 46 ILDS national member societies.
Established measures that quantify the severity of lesions, such as the Psoriasis Area Severity Index (PASI), the Eczema Area and Severity Index (EASI), Investigator Global Assessment (IGA) and SCORing Atopic Dermatitis (SCORAD), are also important guidelines. Yet they have their limitations: for example, an analysis of 317 atopic dermatitis trials found that while a third of the trials employed the IGA as an endpoint, the studies varied considerably “in nomenclature, scale size, definitions, outcome description and analysis.” As a result, little comparison can be made between trials. To remedy this, sponsors should consider using evidence-based disease and regulatory guidelines alongside these measures when selecting tools and criteria for endpoint interpretation.
A new atopic dermatitis measure is tackling subjectivity concerns through computer-assisted lesion measurement. The Objective Severity Assessment of Atopic Dermatitis (OSAAD) creates a score based on electronically-recorded measurements of skin hydration and water loss that are normalized for the magnitude of a patient’s disease.
Tracking lesions with images
Digital photography and other non-invasive imaging tools have changed the face of lesion tracking capabilities. Body mapping, which is enabled through a Wood’s lamp examination and dermoscopy, helps investigators communicate lesion information objectively. Care is necessary, however, to achieve universality: factors such as lighting, positioning, and flash settings need to be standardized to provide a consistent and objective portrayal of lesions.
Recent advances address these challenges by manipulating patient-specific images from previous trial visits to create a “ghost” image used to align future images. Another new technology uses facial recognition software to position a camera with programmable recall to match the camera lens, light, and directional settings for future images. This technology also enables computer-assisted body map tagging of lesions.
With new capabilities in 3-D imaging, researchers can capture the precise shape of lesions on curved body surfaces. The Memorial Sloan Kettering Cancer Center uses total body 3-D imaging and 46 cameras to accurately map lesions on a baseline patient avatar. This allows physicians to visualize changes in lesion appearance over time, providing a great benefit to patients at high risk for melanoma.
For a more comprehensive view of the available tools and solutions to improve objectivity in tracking lesions, read our white paper, “Objectively Tracking Lesions in Dermatology Clinical Trials.”