Therapeutic Indications of Pembrolizumab in Eight Common Cancers: Current Evidence and Future Directions

Pembrolizumab is a monoclonal antibody that inhibits the programmed death-1 (PD-1) receptor pathway, which has increasingly been implicated in cancer treatment regimens. Since its first approval for melanoma in 2014, many trials have investigated the efficacy and safety of this new drug in different cancers. In this review, we discuss the therapeutic advances achieved with pembrolizumab in the management of eight cancers that are associated with a relatively poor prognosis. We also report the FDA approvals of this drug, highlighting promising ongoing trials and potential aspects for future research.

Numerous trials have demonstrated robust anti-cancer effects, high response rates, and a favorable safety profile of pembrolizumab monotherapy or its combination in different lines and treatment settings. With the encouraging survival benefits of this treatment in advanced/metastatic disease, there has been an increasing tendency to explore its therapeutic potential in early-stage disease. Thus, pembrolizumab was effectively added to the standard neoadjuvant chemotherapy regimen for resectable TNBC and NSCLC, followed by adjuvant pembrolizumab monotherapy after resection. Similar positive results were found with the adjuvant administration of pembrolizumab after surgery in resectable RCC and melanoma. Pembrolizumab has also been recently studied in locally advanced resectable gastric and gastroesophageal junction adenocarcinoma as well as early-stage estrogen receptor-positive/human epidermal growth factor receptor 2-negative breast cancer as a neoadjuvant-adjuvant regimen.

The advent of immunotherapeutic agents such as pembrolizumab has unprecedently altered cancer therapy regimens; however, future research efforts should address the need for biomarkers that could better identify patients who would most likely respond to such therapy and investigate new combinations that could overcome resistance to immunotherapy.