Keytruda (pembrolizumab)

The following drug information is obtained from various newswires, published medical journal articles, and medical conference presentations.


Approval Status:

Approved October 2015

Specific Treatments:

PD-L1 positive advanced non-small cell lung cancer

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General Information

Keytruda (pembrolizumab) targets the cellular pathway known as PD-1/PD-L1, proteins found on the body’s immune cells and some cancer cells. By blocking this pathway, Keytruda may help the body’s immune system fight the cancer cells.

Keytruda is specifically indicated for the treatment of patients with metastatic non-small cell lung cancer whose tumors express PD-L1 as determined by an FDA-approved test with disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumor aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving Keytruda.

Keyruda is supplied as a solution for intravenous infusion. The recommended dose of Keytruda is 2 mg/kg administered as an intravenous infusion over 30 minutes every 3 weeks until disease progression or unacceptable toxicity.  

Clinical Results

FDA Approval

The FDA approval of Keytruda for non-small cell lung cancer was based on a subgroup of 61 patients enrolled within a larger multicenter, open-label, multi-part study. The subgroup consisted of patients with advanced NSCLC that progressed following platinum-based chemotherapy or, if appropriate, targeted therapy for certain genetic mutations (ALK or EGFR). This subgroup also had PD-L1 positive tumors based on the results of the 22C3 pharmDx diagnostic test. Study subjects received 10 mg/kg of Keytruda every two or three weeks. The major outcome measure was overall response rate (percentage of subjects who experienced complete and partial shrinkage of their tumors). Tumors shrank in 41 percent of subjects treated with Keytruda and the effect lasted between 2.1 and 9.1 months.

Side Effects

Adverse effects associated with the use of Keytruda may include, but are not limited to, the following:

  • fatigue
  • decreased appetite
  • shortness of breath or impaired breathing (dyspnea)
  • cough

Keytruda also has the potential to cause severe side effects that result from the immune system effect of Keytruda (known as “immune-mediated side effects”).

Mechanism of Action

Binding of the PD-1 ligands, PD-L1 and PD-L2, to the PD-1 receptor found on T cells, inhibits T cell proliferation and cytokine production. Upregulation of PD-1 ligands occurs in some tumors and signaling through this pathway can contribute to inhibition of active T-cell immune surveillance of tumors. Pembrolizumab is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response.

Additional Information

For additional information regarding Keytruda or PD-L1 positive advanced non-small cell lung cancer, please visit