A New Approach to Acne-Like Rashes Caused by Cancer Treatment: A Topical BRAF Inhibitor

Erbitux and Vectibix are examples of EGFR (epidermal growth factor receptor) inhibitors, which play an important role in treating many cancers, particularly colorectal cancer, because they prolong survival. However, a common adverse effect of these treatments is acneiform (acne-like) rash, which reduces quality of life and negatively affects treatment adherence.

Recent research offers a promising new approach to acneiform rashes caused by EGFR inhibitors. According to results from a phase 2 clinical trial presented at the AACR 2025 Annual Meeting,a topical (skin-applied) BRAF inhibitor, LUT014 gel, achieved notable success in treating these skin reactions.

How Acneiform Rashes Undermine Treatment Adherence

Among patients receiving EGFR inhibitors, approximately 90% develop a papulopustular acneiform rash. These rashes are more than a cosmetic problem: they can seriously impair quality of life, leading to treatment interruptions or permanent discontinuation. Previous studies observed this type of rash in 75% of patients receiving EGFR inhibitors, and two-thirds of those patients required a dose change because of the rash.

What Is LUT014 Gel and How Does It Work?

LUT014 gel is a next-generation topical BRAF inhibitor. EGFR inhibitors suppress the MAP kinase pathway in the skin, causing acneiform rashes; the topical BRAF inhibitor LUT014 reverses these effects through a paradoxical mechanism. By activating the MAP kinase pathway only in the skin, the gel targets the mechanism underlying the rash without entering the systemic circulation. Earlier phase 1 studies also confirmed that LUT014 gel showed no systemic absorption and caused no serious adverse effects.

Phase 2 Clinical Trial and Results

This double-blind, placebo-controlled trial enrolled 118 patients receiving cetuximab (Erbitux) or panitumumab (Vectibix) for metastatic colorectal cancer who had moderate-to-severe acneiform rashes. Patients were randomized into three groups to use LUT014 0.1%, LUT014 0.03%, or placebo gel for 4 weeks.

The primary endpoint was a meaningful improvement in rash grade or a marked improvement on a patient-reported quality-of-life scale.

• Treatment success in the high-dose LUT014 (0.1%) group was 74% , statistically significantly higher than the 28% in the placebo group (p=0.0001).
• In the low-dose group (0.03%), the rate was 56% .

In analyses including patients who completed treatment, the success rate in the high-dose group was 85%, compared with 69% in the low-dose group. Patients who did not respond to placebo and subsequently switched to low-dose LUT014 also showed meaningful improvements in their rashes.

Effects on Adherence to Cancer Treatment

An important finding was that LUT014 improved continuation of EGFR inhibitor treatment. Interruptions of EGFR treatment because of skin adverse effects occurred in 16% of patients receiving the topical BRAF inhibitor, versus 26% in the placebo group. This difference was statistically significant in the high-dose group.

Effective rash management may reduce interruptions, improving the effectiveness and continuity of cancer treatment. By supporting adherence, this could improve overall treatment success.

Adverse Effects and Safety Profile

LUT014 gel mainly caused mild adverse effects, most commonly itching or mild skin irritation. Interestingly, more serious skin reactions were reported in the placebo group than in the LUT014 group. This was attributed to the combined effects of leaving the rash untreated and irritation caused by the placebo gel.

Future Use and Clinical Significance

Current treatments for EGFR inhibitor-related rashes include oral tetracyclines, topical steroids, and oral retinoids, but none has been formally approved by regulatory authorities for this indication. The potential for LUT014 to become the first clinically approved topical treatmentcould open a new era in managing skin reactions during cancer treatment.

However, preventive use of LUT014 requires further evaluation, particularly to understand the relationship between EGFR inhibitor-related rashes and the response to cancer treatment.

This new approach therefore represents a promising development for effectively managing skin adverse effects in patients receiving EGFR inhibitors and improving adherence, one of the major challenges in cancer treatment.