It causes almost 8 thousand deaths a year and, in the United States alone, affects 1 million people. Metastatic squamous cell carcinoma of the skin is the second skin cancer by mortality. Aggressive and disfiguring, if diagnosed at an advanced stage this skin cancer is largely disabling and fatal. If diagnosed in time, however, it can be treated with surgery and in selected cases with radiotherapy.
For cases in which the tumor cannot be removed surgically or when the age of the patients is advanced, there are no really effective therapeutic solutions; in particular, the old chemotherapeutic agents do not have the capacity to act deeply and to modify the inauspicious prognosis of this disease. However, a new molecule seems to promise new therapeutic horizons today. We talk about this topic with Dr. Maria Chiara Tronconi, researcher of Humanitas.
The new investigational drug works in 50% of cases
The 54th Congress of the American Society of Clinical Oncology discussed the good results of a new experimental drug, cemiplimab. This is a monoclonal anti-PD-1 antibody, which, when tested on patients, has been shown to be effective in one in two cases.
The phase 2 study was then also conducted in Australia, Germany and the United States: patients with metastatic cancer were followed for almost 8 months and 47% of them responded to therapy. In more than half (57%) of the patients who had a response to the drug, the response exceeded six months. The long-term disease control rate, i.e. the percentage of patients without disease progression for at least 105 days, was 61%.
How the new drug works
It is an immunotherapeutic drug; immuno-oncology attempts to cure cancer through a form of “re-education” of the immune system, often producing very positive effects on stopping tumor growth, with disease remissions that can last several years. In the case of antibodies to PD1 and PD-L1 – immunological therapies exert their action by inhibiting the brake exerted by the tumor cells on T lymphocytes, which thus return to be effective in their activities to control and fight against tumor growth.
Cemiplimab (name of the new anti-PD1 molecule) makes it possible for one in two cases of squamous cell skin tumors to heal in both metastatic and locally advanced forms, with clinically significant results.
Immunotherapy has been shown to be so effective in skin cancer, as has already been amply demonstrated in the case of melanoma and the aggressive and rarer Merkel cell tumor.
Tolerance to treatment seems to be optimal even in the case of cemiplimab, with mild and clinically well manageable degrees of diarrhea, nausea, asthenia and skin rash; moreover, the increasingly common and frequent use of similar immunotherapeutic agents in the oncological field has made early detection and optimal management of even the rarest and most serious adverse events, such as pneumonia, very common.
Squamous cell tumor of the skin is related to ultraviolet rays
Skin squamous cell tumor is related to ultraviolet rays (UVA-UVB) but, unlike melanomas and “white-collar” disease (as it is more related to short and intense exposure to ultraviolet rays, typical of a seaside holiday), the CSCC is typical of those who have had chronic exposure to the sun, as well as light phenotypes. As Professor Ascierto, interviewed at the recent ASCO conference, points out when commenting on the results of the study, cemiplimab gives patients hope: “The experimental molecule responds to an unmet clinical need; chemotherapy, radiotherapy and all the new drugs have not had any impact at the moment. It does not respond to the treatments we have available. When there is a metastatic disease, there is little to do.
We would add that social attention and surveillance remain fundamental in order to prevent pathologies such as scaly skin cancer; a more careful information campaign is therefore required, starting with the school/youth environment, regarding correct exposure to sunlight.
Possible approval of new drug by 2019
The results presented in Chicago are part of the set of data included in the application for approval of cemiplimab, jointly developed by Sanofi and Regeneron, as a potential treatment for advanced CSCC, accepted by the U.S. Food and Drug Administration (FDA), which has recognized its “Breakthrough Therapy Designation”, and by the European Medicines Agency (EMA). The evaluation processes should be completed by 28 October 2018 and the first half of 2019 respectively.
