Keytruda's Main Approved Uses in Cancer
Keytruda (pembrolizumab), a PD-1 inhibitor from Merck, is commonly prescribed for cancers with high PD-L1 expression or microsatellite instability, often in advanced or metastatic stages. The FDA has approved it as monotherapy or in combination for over 30 indications across solid tumors and blood cancers.[1]
Most Common Solid Tumor Prescriptions
- Non-small cell lung cancer (NSCLC): First-line for PD-L1-positive metastatic cases, or after platinum chemotherapy; also adjuvant post-resection.
- Melanoma: Unresectable or metastatic, including adjuvant therapy post-surgery.
- Head and neck squamous cell carcinoma (HNSCC): Recurrent or metastatic, first-line with chemo.
- Triple-negative breast cancer (TNBC): High-risk early-stage or PD-L1-positive metastatic, with chemo.
- Urothelial carcinoma (bladder cancer): Advanced cases after platinum therapy or cisplatin-ineligible first-line.
These account for the bulk of U.S. prescriptions, driven by broad NSCLC and melanoma use.[2]
Approvals in Other Solid Tumors
Keytruda sees frequent off-label or approved use in:
- Renal cell carcinoma: First-line with axitinib.
- Endometrial carcinoma: Advanced MSI-H/dMMR or mismatch repair deficient.
- Colorectal cancer: Unresectable MSI-H/dMMR metastatic.
- Esophageal and gastroesophageal junction cancer: First-line with chemo.
- Cervical cancer: Persistent/recurrent PD-L1-positive with chemo.
Tumor-agnostic approvals cover any MSI-H/dMMR solid tumor or high TMB, expanding use to rare cancers like biliary tract or small bowel.[1]
Blood Cancer and Hematologic Uses
Approved for:
- Classical Hodgkin lymphoma: Relapsed after transplant or multi-agent chemo.
- Primary mediastinal large B-cell lymphoma: Relapsed/refractory.
Less common than solid tumors but standard in refractory cases.[1]
How Doctors Decide on Keytruda
Prescribing hinges on biomarker testing (PD-L1, MSI, TMB), prior treatments, and performance status. It's often first-line in immunotherapy-eligible patients to avoid chemo toxicity. Real-world data shows highest volume in NSCLC (over 40% of scripts), followed by melanoma and HNSCC.[2][3]
[1]: FDA Keytruda Label
[2]: Merck Annual Report 2023
[3]: DrugPatentWatch.com - Keytruda Indications