Q&A: Gene Expression Testing, Ameluz PDT, and the Psoriasis Pipeline

Precision medicine and nonsurgical treatment options were recurring themes across skin cancer and inflammatory disease sessions at the 2026 Fall Clinical Dermatology Conference. Gene expression profile (GEP) testing now extends beyond risk stratification in melanoma into systemic therapy selection for moderate-to-severe atopic dermatitis.

On September 14, 2026, the US Food and Drug Administration (FDA) approved aminolevulinic acid hydrochloride (Ameluz) topical gel, 10%, with the BF-RhodoLED lamp series for adults with superficial basal cell carcinoma.¹ In the supporting phase 3 trial, 66% (95/145) of Ameluz photodynamic therapy recipients achieved a composite clinical and histological complete response of the main target lesion at 12 weeks, versus 5% (2/42) with placebo.¹

New data for the 31-GEP DecisionDx-Melanoma test were presented at the 2026 European Academy of Dermatology and Venereology Congress in Vienna. In a prospective study of 2,799 patients across 29 US centers, those with a predicted sentinel lymph node positivity risk below 5% had an observed rate of 4.4%, versus 22.8% for those above 10%.² Among 565 low-risk patients eligible for sentinel lymph node biopsy who did not undergo the procedure, 5-year recurrence-free survival reached 99.6%.²

In atopic dermatitis, the 487-gene AdvanceAD-Tx test sorts patients into a JAK inhibitor responder profile or a T helper 2 (Th2) molecular profile.³ According to Castle Biosciences, JAK inhibitor responders treated with a JAK inhibitor reached Eczema Area and Severity Index 90 by 3 months at a rate of 45.5%, versus 8.3% with Th2-targeted therapy (P = .021).³

Aaron S. Farberg, MD, a double board-certified dermatologist, fellowship-trained Mohs micrographic surgeon, and chief medical officer at Bare Dermatology in Dallas, Texas, presented on multidisciplinary care in high-risk cutaneous squamous cell carcinoma and biomarker-driven testing. In the following interview, Farberg spoke with HCPLive at Fall Clinical Dermatology in Las Vegas about GEP testing, the Ameluz approval, and the psoriasis pipeline:

HCPLive: What were the key highlights from your session on biomarker-driven testing at Fall Clinical?

Aaron Farberg, MD: We first talked about precision medicine, where I brought up the AdvanceAD-Tx test. That test is ideal for our moderate-to-severe atopic dermatitis patients. Which therapy are you going to pick? Rather than guess or just use simple clinical factors, let’s molecularly align (say that 10 times fast) our therapy with the patient’s disease. This GEP test can actually help guide us in our therapy selection.

Another highlight I’d bring up is that the DecisionDx-Melanoma test, the 31-GEP, just had a release of some of its top data. It was originally launched in Vienna at EADV, where they highlighted a very large, actually the largest, prospective GEP study. Sure enough, it worked: it stratified the patients and met a primary endpoint of identifying a group of patients with a lower than 5% risk of having a positive node. So, success across the board when it comes to precision medicine.

HCPLive: What life and practical advice did you share with early-career clinicians?

Aaron Farberg, MD: Anything you do, make sure you do it well so that you can sleep at night. That’s a cliché way of thinking, but you don’t want to do something where you’re nervous that something is going to go wrong or that it’s going to cause problems. Again, my goal is to do everything above board, be honest, be true, and do the best for your patients.

HCPLive: The FDA approved Ameluz with BF-RhodoLED PDT for superficial basal cell carcinoma. What does this approval mean for practice?

Aaron Farberg, MD: Guess what’s in the news? It’s Ameluz. How great is that rhyme? It’s in the news because it’s now approved for superficial basal cells. Great idea, because guess what? Not every patient wants their skin cancer cut out. “Heal with steel” is a great term, but not everyone wants to be cut on for every single skin cancer, and we all know basal cells are the most common cancer in the world. So this now gives us another alternative, another option to surgery, to help our skin cancer patients.

HCPLive: What research are you currently working on?

Aaron Farberg, MD: I recently submitted a paper showing the utilization of the AdvanceAD-Tx test. That’s the GEP test designed to help therapy selection in our atopic dermatitis patients. Here, you can see it’s utilized to help identify Th2 drugs, whether or not you’d switch to a JAK inhibitor, or it could even help guide some of your topical therapy. It’s a great way of thinking about our new approach to therapy selection in our moderate-to-severe atopic dermatitis patients.

HCPLive: For patients with psoriasis, atopic dermatitis, or hidradenitis suppurativa, and psoriasis, what are you looking forward to this year?

Aaron Farberg, MD: What am I looking forward to in inflammatory disease: atopic dermatitis, hidradenitis suppurativa, psoriasis? Guess what? They’re all here to stay, and they’re coming back roaring. In psoriasis, there are so many new molecules in the pipeline that I can’t even go through them all. But if you think we’re done, no. There are even better ones coming, so get excited, because psoriasis is going to be talked about, I’d say, for the rest of our lives.

Editor’s Note: This transcript has been edited for grammar and clarity using artificial intelligence tools.

References

1. Smith T. Ameluz treatment becomes first FDA-approved PDT for skin cancer. HCPLive. Published September 14, 2026. Accessed October 15, 2026. https://www.hcplive.com/view/ameluz-treatment-becomes-first-fda-approved-pdt-skin-cancer.

2. Castle Biosciences. Castle Biosciences launches AdvanceAD-Tx to help guide systemic treatment decision making in patients with moderate-to-severe atopic dermatitis. Published November 3, 2025. Accessed October 15, 2026. https://www.biospace.com/press-releases/castle-biosciences-launches-advancead-tx-to-help-guide-systemic-treatment-decision-making-in-patients-with-moderate-to-severe-atopic-dermatitis.