Pembrolizumab is a humanized monoclonal antibody (IgG4/kappa isotype) that acts as a programmed death receptor-1 (PD-1) blocking agent. It is a revolutionary immune checkpoint inhibitor used in oncology to treat various cancers by enhancing the body's T-cell-mediated immune response against tumor cells. In the Indian market, it is a critical component of modern cancer immunotherapy regimens.
Adult: 200 mg every 3 weeks OR 400 mg every 6 weeks, administered as an intravenous infusion over 30 minutes. Dosing is based on flat dose, not body weight, for most approved indications.
Note: Dilute the 100mg vial in 0.9% Sodium Chloride Injection or 5% Dextrose Injection to a final concentration between 1 mg/mL and 10 mg/mL. Administer as an IV infusion over 30 minutes using a sterile, non-pyrogenic, low-protein binding in-line filter (0.2 to 5 micron). Do not administer as an IV push or bolus. Flush line with NaCl or D5W before and after infusion.
Pembrolizumab binds to the PD-1 receptor on the surface of T-cells, blocking its interaction with its ligands PD-L1 and PD-L2, which are often overexpressed on tumor cells and tumor-infiltrating cells. This blockade releases the PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response, leading to decreased tumor growth.
Pregnancy: Category D: Based on its mechanism, pembrolizumab can cause fetal harm. Animal studies show increased risk of abortion and stillbirth. Women of childbearing potential should use effective contraception during and for at least 4 months after the last dose.
Driving: Fatigue is a common side effect. Patients should be cautioned about the potential for dizziness and fatigue, which may impair the ability to drive or operate machinery.
| Systemic Corticosteroids (≥10 mg prednisone/day equivalent) | May reduce efficacy of pembrolizumab by suppressing the immune system. Used for managing irAEs, but avoid prior to initiation. | Major |
| Other Immunosuppressants (e.g., TNF inhibitors, methotrexate, azathioprine) | May diminish therapeutic effect and increase risk of infections. | Major |
| Live Vaccines (e.g., MMR, Yellow Fever, Varicella) | Increased risk of disseminated infection. Avoid during and for at least 4 weeks after treatment. | Major |
| Allogeneic Hematopoietic Stem Cell Transplant | Increased risk of graft-versus-host disease (GVHD) and transplant-related complications. | Major |
Same composition (Pembrolizumab (100mg)), different brands: