Keytruda, also known as pembrolizumab, was first approved by the US Food and Drug Administration (FDA) in September 2014 [1]. At that time, it was approved for the treatment of patients with advanced non-small cell lung cancer (NSCLC) whose tumors expressed programmed death-ligand 1 (PD-L1) and had not received prior chemotherapy.

However, in October 2015 [2], the FDA granted accelerated approval to Keytruda for the treatment of patients with melanoma that had spread to other parts of the body (also known as unresectable or metastatic melanoma), who had received prior treatment with ipilimumab or a BRAF inhibitor. In November 2015 [3], Keytruda was also approved for the treatment of patients with advanced squamous cell carcinoma of the head and neck (SCCHN).

Since its initial approval, Keytruda has received numerous additional approvals for various indications, including the treatment of advanced and metastatic non-small cell lung cancer, melanoma, HCC, SCLC, urothelial carcinoma, and more [4].

As of now, Keytruda remains an extensively studied and widely used cancer immunotherapy, with a vast array of research and clinical trials ongoing to evaluate its safety and efficacy in different settings and patient populations [5].

Sources:
[1] https://www.drugpatentwatch.com/patent/1456-1037 (FDA Approval: Pembrolizumab)
[2] https://www.drugpatentwatch.com/patent/1472-1041 (Additional FDA Approval: Pembrolizumab)
[3] https://www.drugpatentwatch.com/patent/1475-1033 (Further Additional FDA Approval: Pembrolizumab)
[4] https://www.drugpatentwatch.com/patent/Keytruda-pembrolizumab (Keytruda/Pembrolizumab Patent Page)
[5] (Ongoing Keytruda/Pembrolizumab Clinical Trials)