See the DrugPatentWatch profile for keytruda

Keytruda, a cancer drug manufactured by Merck & Co., primarily targeted melanoma at the time of its launch. Melanoma is a type of skin cancer that develops when unrepaired DNA damage to skin cells triggers mutations (typically caused by ultraviolet radiation from sunshine or tanning beds) that lead skin cells to multiply rapidly and form malignant tumors [1].

Keytruda, also known by its generic name pembrolizumab, is a type of medication called an immune checkpoint inhibitor. It works by blocking a protein called PD-1, found on T cells (a type of white blood cell), allowing the T cells to attack cancer cells [2].

At the time of Keytruda's approval by the U.S. Food and Drug Administration (FDA) in September 2014, it was specifically approved for the treatment of unresectable or metastatic melanoma in patients who had already received other forms of treatment [3]. Since then, Keytruda's indications have expanded to include the treatment of several other types of cancer [4].

Sources:
[1] American Cancer Society. (2021). What is Melanoma Skin Cancer? Retrieved from <https://www.cancer.org/cancer/melanoma-skin-cancer/about/what-is-melanoma.html>
[2] National Cancer Institute. (2019). Pembrolizumab. Retrieved from <https://www.cancer.gov/about-cancer/treatment/drugs/pembrolizumab>
[3] U.S. Food and Drug Administration. (2014). FDA approves new treatment for advanced skin cancer. Retrieved from <https://www.fda.gov/news-events/press-announcements/fda-approves-new-treatment-advanced-skin-cancer>
[4] Merck & Co., Inc. (2021). Keytruda (pembrolizumab) indications. Retrieved from <https://www.merck.com/product/usa/pi_circulars/k/keytruda/keytruda_pi.pdf>