D-TECT: Pretreatment D-dimers and Disease Control in Advanced cSCC Treated With Cemiplimab

D-TECT is a prospective, multicenter, non-interventional observational study investigating whether pretreatment D-dimer levels predict disease control in patients with locally advanced or metastatic cutaneous squamous cell carcinoma treated with cemiplimab in routine clinical care. D-dimers are routinely available laboratory markers related to activation of the coagulation system. Previous single-center data suggest that elevated pretreatment D-dimer levels may be associated with poorer disease control under cemiplimab. In D-TECT, a single pretreatment D-dimer value and prospectively collected routine clinical follow-up data will be analyzed to validate this association in a multicenter real-world setting. No study-specific treatment decisions, imaging procedures, or additional blood draws are mandated by the study.

Inclusion Criteria: * Histologically confirmed locally advanced or metastatic cutaneous squamous cell carcinoma * Planned initiation of systemic treatment with cemiplimab as part of routine clinical care * Pretreatment D-dimer measurement performed within 7 days before initiation of cemiplimab treatment up to the day of first administration before infusion * Age 18 years or older at the time of consent * ECOG performance status 0 to 2 * Written informed consent for study participation and pseudonymized collection and analysis of clinical and laboratory data Exclusion Criteria: * Prior treatment with immune checkpoint inhibitors in curative or palliative intent for cutaneous squamous cell carcinoma * Concurrent second malignancy requiring systemic treatment, such as chemotherapy, immunotherapy, or targeted therapy * Clinically unstable comorbidity, including NYHA class III-IV heart failure or active systemic infection * Acute symptomatic thrombosis or pulmonary embolism within 4 weeks before the pretreatment D-dimer measurement * Incidental asymptomatic thromboembolic events detected during clinical diagnostic work-up or following an elevated D-dimer result are not exclusion criteria and will be documented * Physician-estimated life expectancy of less than 3 months or severe non-tumor-related comorbidity likely to preclude assessment of the clinical course within the first 6 months * Lack of capacity to consent or legal guardianship without valid legal representation