The goal of this clinical trial is to evaluate the safety, tolerability, and clinical outcomes of a dose-modulation strategy of Sonidegib in adult patients with locally advanced periocular basal cell carcinoma (laBCC) who are not candidates for surgery or radiotherapy. The main questions it aims to answer are:

• Can dose-adjusted Sonidegib treatment preserve ocular function and avoid disfiguring surgery in laBCC patients?
• What is the rate of tumor response, recurrence, and adverse events during dose-modulated treatment?

Researchers will compare different dosing regimens based on treatment response, tolerability, and toxicity profiles to assess whether intermittent dosing or dose reductions can maintain clinical benefits while minimizing adverse effects.

This monocentric retrospective observational real-world evidence (RWE) study included 12 patients (8 male, 4 female; aged between 67 and 92 years; mean 83.25 years) with histologically confirmed periocular laBCC (staged T3-T4b) treated with sonidegib between 2021-2023 at the Oculoplasty Unit of the University of Naples Federico II. Eligible patients were those for whom conventional surgery or radiotherapy would result in loss of vision or unacceptable cosmetic outcomes.

Participants:

• Took Sonidegib orally, starting at 200 mg daily, with possible dose interruptions or reductions based on individual tolerance and tumor response.
• Underwent clinical and ophthalmologic evaluations every 4-6 weeks.
• Had imaging and dermatologic assessments to monitor tumor regression.
• Completed follow-up visits after treatment completion to assess long-term control and safety.

The results of this study aim to support an eye-sparing, patient-centered approach for complex periocular tumors.

This monocentric, open-label, real-world study investigated the clinical efficacy and tolerability of Sonidegib, a selective Hedgehog pathway inhibitor, in the treatment of locally advanced periocular basal cell carcinoma (laBCC). The study specifically focused on patients for whom standard surgical or radiotherapy options were contraindicated due to the risk of vision loss, functional impairment, or unacceptable cosmetic outcomes.

A total of 12 adult patients with histologically confirmed periocular laBCC were enrolled at the Oculoplasty Unit of the University of Naples Federico II. Inclusion criteria targeted individuals with tumors in functionally or aesthetically sensitive locations-such as the eyelid margins, medial/lateral canthi, or deep orbital tissues-where conventional excision would require extensive, disfiguring surgery. All patients received oral Sonidegib 200 mg daily as first-line systemic therapy.

A dose-modulation strategy was implemented in response to adverse effects or individual tolerance, allowing temporary drug interruption or reduced-frequency administration. This personalized therapeutic approach aimed to preserve treatment adherence and quality of life while maintaining tumor control.

Patients were monitored through multidisciplinary follow-up visits at regular intervals, including dermatologic evaluation, photographic tumor documentation, and ophthalmologic assessments such as best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, and fundus examination. Tumor response was assessed using clinical measurements and standardized criteria adapted for periocular anatomy.

The primary endpoint was the proportion of patients achieving disease control (complete response, partial response, or stable disease) without requiring exenteration or vision-threatening surgery. Secondary endpoints included time to response, duration of therapy, adverse event frequency and severity (graded per CTCAE), patient-reported functional and cosmetic outcomes, and post-treatment recurrence rates.

This study offers preliminary real-world evidence that Sonidegib, when administered with a flexible dosing strategy, can achieve significant therapeutic responses while minimizing toxicity in patients with complex periocular laBCC. The results support its role as an eye-sparing, function-preserving alternative to surgery in selected cases.

Inclusion Criteria:

• Adults (≥18 years) with histologically confirmed, locally advanced periocular basal cell carcinoma (laBCC)
• Tumor location or extent deemed unsuitable for surgical resection or radiotherapy due to high risk of orbital invasion, vision loss, or cosmetic disfigurement
• ECOG performance status 0-2
• Life expectancy ≥12 months
• Willing and able to comply with study procedures and follow-up assessments
• Provided written informed consent

Exclusion Criteria:

• Evidence of metastatic basal cell carcinoma
• Prior treatment with Hedgehog pathway inhibitors
• History of other malignancies within 5 years (except adequately treated non-melanoma skin cancer or carcinoma in situ)
• Severe hepatic or renal impairment
• Active systemic infection or uncontrolled medical conditions
• Pregnant or breastfeeding women
• Inability to undergo dermatologic or ophthalmologic evaluation due to physical or cognitive impairment

The study population consisted of 12 adult patients with histologically confirmed, locally advanced periocular basal cell carcinoma (laBCC), all enrolled and treated at the Oculoplasty Unit of the University of Naples Federico II. All participants were treatment-naïve and presented with tumors unsuitable for surgical excision or radiotherapy due to the high risk of vision loss or anatomical disruption. The cohort included 8 males and 4 females, aged between 67 and 92 years, with a mean age of 83.25 years. The study was conducted in a real-world clinical setting and aimed to preserve ocular function and periocular anatomy through targeted oral therapy with Sonidegib.