DermTech, Inc. (NASDAQ: DMTK) stock was rising 27.83% to reach $18.28 in the aftermarket following the published the topline results of the TRUST Study, a non-invasive melanoma rule-out test using the Pigmented Lesion Assay. The TRUST study was intended to assess the long-term outcomes of the PLA negative results of pigmented skin lesions. It also serves to support further the 99% negative predictive value of the PLA. To determine the proportion of true negative lesions among all those that tested negative, the study protocol called for retesting PLA-negative lesions 12 to 24 months before each subject’s enrollment in the TRUST Study.
It helps identify melanoma in the early stages by detecting atypical pigmented lesions to help rule out the melanoma and the need for surgical procedures. The PLA identifies the LINC 518 and PRAME genes in a two-panel gene expression assay.
The TRUST study was conducted at five clinical sites in the U.S. that use the PLA to help manage atypical pigmented lesions in their clinical practice.
An assessment of a long-term follow-up cohort of 1,781 lesions with PLA negative testing in a 12 to 24 month period preceding the study’s start resulted in 302 lesions undergoing PLA testing and meeting the study’s prespecified enrollment target.
NPV and patient outcome measures for the full cohort of eligible lesions were established by prospectively reviewing charts for any melanoma diagnoses on the PLA tested lesion, late-stage diagnoses of melanoma, and melanoma mortality. There were no deaths or diagnoses of late-stage melanoma in the full cohort of 1,781 lesions. In total, ten lesions from the full cohort were diagnosed with melanoma after initial testing, four of which were Stage 0 lesions (in situ) and six Stage 1a lesions.
A subset of the full cohort, representing 1,233 lesions, confirmed follow-up evaluations on the PLA-negative test, and we calculated an NPV of 99.2% (CI95%= 98.5 – 99.6) from these evaluations.