Immunotherapy / Oncology

Keytruda (pembrolizumab)

Merck · PD-1 Immune Checkpoint Inhibitor

FDA Approved 2014 Intravenous (IV) infusion Oncology Specialty

What is Keytruda? Keytruda (pembrolizumab) is a PD-1 immune checkpoint inhibitor manufactured by Merck. It is one of the most widely approved oncology immunotherapy medications in the United States.

About Keytruda

Brand NameKeytruda
Generic / INNpembrolizumab
Drug ClassPD-1 Immune Checkpoint Inhibitor
ManufacturerMerck
AdministrationIntravenous (IV) infusion
FDA Approval2014
PresentationKeytruda is available in 100 mg/4 mL (25 mg/mL) solution vials.

FDA-Approved Uses for Keytruda

The following indications are based on FDA approval as of the last review date. Your oncologist will determine appropriate use based on your specific cancer type, stage, biomarker status, and overall treatment plan.

  • Melanoma (unresectable or metastatic; adjuvant)
  • Non-small cell lung cancer (NSCLC)
  • Head and neck squamous cell carcinoma (HNSCC)
  • Classical Hodgkin lymphoma
  • Primary mediastinal B-cell lymphoma
  • Urothelial carcinoma
  • Colorectal cancer (MSI-H or dMMR)
  • Gastric / gastroesophageal junction adenocarcinoma
  • Esophageal cancer
  • Cervical cancer
  • Hepatocellular carcinoma
  • Merkel cell carcinoma
  • Renal cell carcinoma
  • Endometrial carcinoma
  • Tumor mutational burden-high (TMB-H) cancer
  • Cutaneous squamous cell carcinoma
  • Biliary tract cancer
  • Colorectal cancer (MSS/pMMR, first-line combination)
  • Triple-negative breast cancer
  • Non-small cell lung cancer (neoadjuvant)
Biomarker Note: Pembrolizumab response may depend on PD-L1 expression (TPS or CPS), MSI-H/dMMR status, or TMB-H status depending on the indication. Biomarker testing should be performed per clinical guidelines.

How Does Keytruda Work?

Keytruda works by blocking the PD-1 receptor on T cells. Tumors can exploit the PD-1/PD-L1 pathway to suppress immune detection. By blocking PD-1, pembrolizumab restores the ability of T cells to recognize and attack cancer cells.

Dosage & Administration

200 mg every 3 weeks or 400 mg every 6 weeks, administered as an IV infusion over 30 minutes. Actual dosing regimens are determined by the treating oncologist based on the indication, combination therapy, and patient factors.

⚠️ Important

Dosing for oncology medications is individualized by the treating oncologist or oncology pharmacist. Do not adjust dosing without consulting your healthcare team. The information on this page is educational only and does not replace the official prescribing information or your provider's guidance.

Warnings, Precautions & Side Effects

General Warning

Immune-mediated adverse reactions can affect any organ system, including pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, skin reactions, and encephalitis. These can be severe or fatal. Infusion-related reactions may occur.

⛔ Serious Warnings & Precautions
  • Immune-mediated pneumonitis
  • Immune-mediated colitis
  • Immune-mediated hepatitis
  • Immune-mediated endocrinopathies
  • Immune-mediated nephritis
  • Embryo-fetal toxicity

Common Side Effects

  • Fatigue
  • Musculoskeletal pain
  • Decreased appetite
  • Rash
  • Nausea
  • Diarrhea
  • Constipation
  • Cough
  • Dyspnea
  • Fever

This is not a complete list. Report any new or worsening symptoms to your oncologist or healthcare provider promptly.

Storage & Handling

Refrigerate at 2°C to 8°C (36°F to 46°F). Do not freeze. Protect from light.

Oncology medications require careful handling. BiologicHealthPlus provides cold-chain specialty delivery with temperature monitoring for medications that require refrigeration. Do not use the medication if the storage chain has been compromised.

Insurance Coverage, Prior Authorization & Patient Assistance

🛡️ Commercial Insurance

Keytruda is a specialty oncology medication covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage varies by plan, indication, and formulary tier. BiologicHealthPlus verifies benefits at no cost to patients.

✅ Prior Authorization

Prior authorization is required by virtually all insurance plans for Keytruda. Our team handles the full prior authorization process — submitting clinical documentation, peer-to-peer reviews when needed, and appeals — at no cost to patients or providers.

🏥 Medicare & Medicaid

Medicare coverage for oncology medications depends on route of administration. Intravenous oncology medications are typically covered under Medicare Part B (medical benefit) when administered in a clinical setting. Subcutaneous formulations may be covered under Part B or Part D depending on administration circumstances. Medicaid coverage varies by state.

🆓 Patient Assistance Programs

Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. BiologicHealthPlus can assess your eligibility and help with the application process. Contact our team for a confidential eligibility review.

Prior Authorization Guide Patient Assistance Programs Insurance & Savings Medication Costs

Frequently Asked Questions About Keytruda

Keytruda (pembrolizumab) is a PD-1 immune checkpoint inhibitor manufactured by Merck. It helps the immune system detect and fight cancer cells by blocking the PD-1 pathway that tumors use to evade immune surveillance.

Keytruda has received FDA approval for more than 20 tumor types and indications, including melanoma, non-small cell lung cancer, head and neck cancer, urothelial carcinoma, cervical cancer, colorectal cancer, and others with specific biomarker criteria.

Keytruda is given as an intravenous (IV) infusion, typically 200 mg every 3 weeks or 400 mg every 6 weeks, administered over 30 minutes in an oncology clinic or infusion center.

Keytruda is covered by most major commercial insurance plans and Medicare Part B when medically indicated. Prior authorization is typically required. Coverage depends on the specific indication, biomarker status, and plan. Contact BiologicHealthPlus for a benefits verification.

Yes. Prior authorization is required by virtually all insurance plans for Keytruda. BiologicHealthPlus handles prior authorization at no cost to patients.

Yes — Keytruda Qlex (pembrolizumab / berahyaluronidase alfa-pmph) is a subcutaneous formulation of pembrolizumab approved by the FDA. It offers a faster administration alternative to IV infusion for certain patients.

Related Medications

Tecentriq  ·  Keytruda Qlex  ·  Opdivo  ·  Atezolizumab

Related Conditions

Non-small cell lung cancer  ·  Melanoma  ·  Urothelial carcinoma  ·  Cervical cancer

Comparisons

Tecentriq Keytruda Qlex

Authoritative References

Medical Information Disclaimer: The information on this page is for general educational purposes only and does not constitute medical advice, diagnosis, or treatment recommendation. Always consult your oncologist, hematologist, or qualified healthcare professional before starting, stopping, or changing any cancer treatment. Drug interactions, contraindications, and individual patient factors must be evaluated by a licensed clinician. Last reviewed: July 2026 by the BiologicHealthPlus Clinical Team.