Medication Monitor



Generic Name (Trade Name—Company)
Notes
June 25, 2019

Pembrolizumab

(Keytruda—Merck)
Pembrolizumab approved as first-line treatment of head and neck squamous cell carcinoma

FDA approved pembrolizumab for first-line treatment of patients with metastatic or unresectable recurrent head and neck squamous cell carcinoma (HNSCC).

Pembrolizumab was approved for use in combination with platinum and fluorouracil for all patients and as a single agent for patients whose tumors express PD‑L1 (Combined Positive Score [CPS] ≥1) as determined by an FDA‑approved test. 

FDA also expanded the intended use for the PD-L1 IHC 22C3 pharmDx kit to include use as a companion diagnostic device for selecting patients with HNSCC for treatment with pembrolizumab as a single agent.

Approval was based on KEYNOTE-048, a randomized, multicenter, three-arm, open‑label, active‑controlled trial conducted in 882 patients with metastatic HNSCC who had not previously received systemic therapy for metastatic disease or with recurrent disease who were considered incurable by local therapies.

The trial demonstrated a statistically significant improvement in overall survival in the overall population for patients randomized to pembrolizumab plus chemotherapy compared with cetuximab plus chemotherapy at a prespecified interim analysis.

It also demonstrated statistically significant improvements in OS for the subgroups of patients randomized to pembrolizumab as a single agent compared with cetuximab plus chemotherapy. 

There were no significant differences in progression-free survival for either pembrolizumab-containing arm compared with the cetuximab plus chemotherapy arm in any population.

The most common adverse reactions of patients who received pembrolizumab as a single agent were fatigue, constipation, and rash. The most common adverse reactions in patients who received pembrolizumab in combination with chemotherapy were nausea, fatigue, constipation, vomiting, mucosal inflammation, diarrhea, decreased appetite, stomatitis, and cough.

The recommended pembrolizumab dosage for HNSCC is 200 mg administered as an I.V. infusion over 30 minutes every 3 weeks until disease progression, unacceptable toxicity, or up to 24 months in patients without disease progression.