Keytruda (pembrolizumab) is a medication that belongs to the class of immune checkpoint inhibitors. It works by blocking the PD-1 protein on T cells, which allows the immune system to attack cancer cells. While Keytruda has been successful in treating various types of cancer, including melanoma, lung cancer, and bladder cancer, it is important to consider the potential long-term side effects of the drug.

According to the National Cancer Institute, long-term side effects of immune checkpoint inhibitors like Keytruda can include autoimmune disorders, where the immune system attacks healthy cells in the body. These disorders can affect various organs and tissues, such as the lungs, liver, and thyroid gland. Symptoms of autoimmune disorders may include fatigue, skin rash, joint pain, and digestive issues.

Additionally, a study published in the Journal of Clinical Oncology found that patients who received immune checkpoint inhibitors like Keytruda for melanoma had a higher risk of developing thyroid disorders, diabetes, and other autoimmune conditions compared to those who did not receive the treatment. The study also noted that these side effects could occur months or even years after treatment.

While Keytruda has been shown to be effective in treating cancer, it is important to discuss potential long-term side effects with a healthcare provider. Patients should also be monitored closely for any signs of autoimmune disorders or other side effects during and after treatment.

Sources:
[1] https://www.cancer.gov/news-events/cancer-currents-blog/2021/immune-checkpoint-inhibitors-melanoma-long-term-side-effects
[2] https://www.drugpatentwatch.com/p/biologics/tradename/KEYTRUDA
[3] https://www.goodrx.com/pembrolizumab/long-term-effects-of-keytruda
[4] Weber, J. S., et al. (2018). Safety Profile of Nivolumab Monotherapy: A Pooled Analysis of Patients With Advanced Melanoma. Journal of Clinical Oncology, 36(10), 785-792. doi: 10.1200/jco.2016.70.7395.