On September 28, 2018, the U.S. Food and Drug Administration (FDA) approved Libtayo® (cemiplimab-rwlc) for the treatment of metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC). This approval is important as it is the first and only treatment available for advanced CSCC. Libtayo is marketed by a joint venture between Sanofi and Regeneron.1,2
About cutaneous squamous cell carcinoma
CSCC is the second most common type of skin cancer (with basal cell carcinoma being the first) and often develops on areas of skin that have received regular sun exposure or other exposure to ultraviolet radiation. Most CSCC are treated successfully with surgical removal, but a small percentage of people experience advanced disease that doesn’t respond to surgery or radiation. When skin cancer metastasizes (spreads) to other organs in the body, it can be life-threatening. CSCC causes an estimated 7,000 deaths each year. Before Libtayo, when surgery and radiation failed to stop CSCC from spreading, there were no options available for these patients.1,2
A new approach: PD-1
Libtayo is a PD-1 (programmed cell death protein-1) blocker. PD-1 is a receptor found on specific immune system cells, including T cells, and on some cancer cells. When activated, this pathway can turn off the immune system’s action of attacking cells. Cancer cells have mutations (changes) that enable them to evade the immune system and grow uncontrollably, and some cancers use the PD-1 pathway.3 Libtayo blocks this pathway, enabling the immune system to better fight off these cancers.1
Libtayo was evaluated in clinical trials with 108 patients with CSCC: 75 had metastatic disease and 33 had locally-advanced disease. The study investigators measured the total response rate, including the shrinking of tumor size or complete disappearance of tumors. The data showed that 47.2% of the patients had their tumors shrink or disappear. The majority of these patients were still experiencing positive effects (their tumors shrinking) of treatment at the time of the data analysis.1
Libtayo received an expedited approval process from the FDA. It was designated as a Breakthrough Therapy, which recognizes drugs that have the potential for significant improvement in the treatment of a serious or life-threatening condition.2
Possible side effects
The most common side effects experienced by patients receiving Libtayo are fatigue, rash, and diarrhea. Libtayo may cause serious side effects, including causing the immune system to attack healthy organs or tissues in the body. Some reactions have been life-threatening or may lead to death, including lung problems, intestinal problems, liver problems, hormone gland problems, skin problems, and kidney problems.1,4
While receiving Libtayo, patients should be monitored for infusion-related reactions.1 Infusion-related reactions are a rare but potentially serious hypersensitivity (allergic) reaction, which may cause symptoms such as itching, fever, chills, and difficulty breathing. Treatment for infusion-related reactions may involve other medications or slowing the infusion rate.5
Dosing and cost
Libtayo is given as an intravenous (IV) infusion over 30 minutes. The recommended dose of Libtayo is 350 mg given once every three weeks, until disease progression or unacceptable toxicity (the side effects become intolerable).1,4
The list price of the treatment is $9,100 per three-week treatment cycle. However, this does not take into account insurance coverage, co-pay support, or patient assistance programs, and the actual cost to patients is expected to be lower. Sanofi and Regeneron have announced Libtayo Surround™, a program to help patients understand insurance coverage of Libtayo and help eligible individuals with financial assistance.2
FDA approves first treatment for advanced form of the second most common skin cancer. U.S. Food and Drug Administration. Available at https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm622044.htm. Accessed 9/29/18.
Sanofi: FDA approves Libtayo® (cemiplimab) as first and only treatment for advanced cutaneous squamous cell carcinoma. Globe Newswire. Available at https://globenewswire.com/news-release/2018/09/28/1587327/0/en/Sanofi-FDA-approves-Libtayo-cemiplimab-as-first-and-only-treatment-for-advanced-cutaneous-squamous-cell-carcinoma.html. Accessed 9/29/18.
Immune checkpoint inhibitors to treat cancer. American Cancer Society. Available at https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/immunotherapy/immune-checkpoint-inhibitors.html. Accessed 9/29/18.
Libtayo prescribing information. Available at https://www.regeneron.com/sites/default/files/Libtayo_FPI.pdf. Accessed 9/29/18.
McBride A, Ngo N, Campen C. Infusion-related reactions. The Oncology Nurse. http://www.theoncologynurse.com/top-issues/2010-issues/may-vol-3-no-3/10516-top-10516. Accessed 9/29/18.