This is an open label, monocentric, uncontrolled phase II trial with Dacomitinib, a pan-HER inhibitor, in unresectable or metastatic skin SCC.

HER2 expression is common in skin SCC, being reported with high rates, even if in small studies.

Coexpression of EGFR, HER2 and HER3 is present in skin SCCs but not in normal skin and it could be associated with the malignant phenotype. In this frame Dacomitinib could play a role in the increase of the response rate.

The patients will assume Dacomitinib 30 mg daily for the first 2 weeks. If the highest skin toxicity will be of grade <2, then the patients will start dacomitinib at 45 mg once daily and they will be clinically assessed every cycle (i.e. every 28 days).

If the highest skin toxicity will be grade >2, then the patient will interrupt the treatment following the criteria for dose reduction.

Tumor evaluation will be performed at baseline and every other cycle. Response will be assessed according to RECIST 1.1. The patient will continue to assume the study drug until disease progression, unacceptable toxicity or any medical condition that will suggest to stop the treatment for patient's safety

Inclusion Criteria:

• Signed informed consent to treatment
• Histological diagnosis of squamous cell carcinoma of the skin not amenable to surgical treatment with curative purposes or with clinical contraindication to surgery (examples of medical contraindications to surgery include but are not limited to: skin SCC that has recurred in the same location after two or more surgical procedures and curative resection is deemed unlikely; anticipated substantial morbidity and/or deformity from surgery (e.g., removal of all or part of a facial structure, such as nose, ear, eyelid, eye; or requirement for limb amputation); anticipated difficulty in obtaining a curative resection due to the location of the tumour, the size of disease; anticipated difficulty in reconstructing the area that will be surgically removed; significant comorbidities that preclude the feasibility of a radical surgery
• Presence of measurable disease according to RECIST 1.1
• ECOG performance status 0-2
• Age≥ 18 years
• For men and women in the fertile period: the use of birth control systems during treatment

Exclusion Criteria:

• Previous treatment with tyrosine kinase inhibitors or monoclonal antibodies directed against EGFR
• Any toxicity CTC grade> 2 from previous treatments not yet resolved
• Pregnant or breastfeeding