Pembrolizumab (Keytruda).

Area of Science:

• Immunology
• Oncology
• Pharmacology

Background:

• Programmed cell death protein 1 (PD1) is a key immune checkpoint regulating T-cell responses.
• PD1/PDL1 interactions facilitate tumor immune evasion by inducing T-cell exhaustion.
• Blockade of the PD1 pathway is a validated cancer immunotherapy strategy.

Purpose of the Study:

• To review the efficacy and safety of pembrolizumab, a humanized anti-PD1 monoclonal antibody.
• To assess pembrolizumab's role in treating various malignancies, including melanoma and non-small cell lung cancer (NSCLC).
• To explore potential predictive markers for pembrolizumab response.

Main Methods:

• Review of clinical trial data for pembrolizumab in malignancies.
• Analysis of overall response rates (ORRs) and adverse events.
• Investigation of correlations between tumor PDL1 expression, gene mutation burden, and treatment outcomes.

Main Results:

• Pembrolizumab demonstrated ORRs of 21-34% in refractory melanoma and 19-25% in refractory NSCLC.
• The drug showed superiority over ipilimumab in advanced melanoma.
• Preliminary data in lymphomas and other solid tumors indicated ORRs of 20-50%.
• High tumor mutation burden correlated with better response.
• Adverse events occurred in up to 60% of patients, with severe toxicities (<10%) and immune-related events.

Conclusions:

• Pembrolizumab is an effective immunotherapy for advanced melanoma and NSCLC.
• Tumor PDL1 expression and high gene mutation burden may predict response.
• While generally well-tolerated, immune-related adverse events necessitate careful patient monitoring.