Study design: A prospective, interventional, non-randomized, multicenter, phase II clinical trial.~Hypothesis:~Cemiplimab is registered for the use in patients with cutaneous squamous-cell carcinoma. In these patient groups cemiplimab showed impressive results. There are numerous similarities between cutaneous squamous-cell carcinoma and secondary angiosarcomas. Based on these similarities, including a complex genetic background, PD-L1 expression and MYC expression, the investigators hypothesize that cemiplimab might be an effective treatment for locally advanced and metastatic secondary angiosarcomas.~Primary Objective:~To evaluate the overall response rate (ORR) after 24 weeks of cemiplimab in secondary angiosarcomas, according to Response Evaluation Criteria in Solid Tumours (RECIST) 1.1 or daylight photography as per WHO Offset Publication No. 48.~Secondary Objectives:~Secondary objectives include the establishment of the best ORR, median time to response, duration of response and progression free survival. The secondary objectives also comprise safety and toxicity quantification and to investigate the relation between response to cemiplimab and various tumor characteristics.~Study Population:~Patients eligible for inclusion are at least 18 years of age, with adequate organ function, who have a histologically confirmed diagnosis of progressive unresectable locally advanced or metastatic secondary angiosarcoma. Patients eligible are patients in the first line of treatment if they are unfit for chemotherapy and patients in advanced lines of systemic treatment. Major exclusion criteria include significant ongoing autoimmune disease that requires immunosuppressive treatment, prior treatment with immune checkpoint inhibitors, active uncontrolled infections or recent pneumonitis. All patients will provide Informed Consent prior to inclusion in the study and during the course of the trial, al relevant data will be stored in electronic Case Report Forms (eCRF).~Treatment Schedule:~After study inclusion, patients will be treated with Cemiplimab 350mg intravenously every three weeks. Patients will receive treatment until disease progression or discontinuation due to unacceptable toxic effects, withdrawal of consent or other reasons. The maximum treatment period will be two years, as is standard of care for patients treated with immunotherapy.
Secondary angiosarcomas are aggressive mesenchymal tumors with a poor prognosis and limited therapeutic options. Recent studies conducted in patients with cutaneous squamous-cell carcinoma provide evidence that cemiplimab has the potential to be an effective treatment also for patients with secondary angiosarcomas.~The purpose of this study is to evaluate the overall response rate after 24 weeks of cemiplimab treatment in patients with locally advanced or metastatic secondary angiosarcomas.~The investigators hypothesis is that cemiplimab could be an effective treatment for patients diagnosed with locally advanced and metastatic secondary angiosarcomas.