The regulator has approved Keytruda as monotherapy and also in combination with a commonly used chemotherapy regimen – platinum and fluorouracil (FU).
The approval is for first-line treatment of metastatic or with unresectable, recurrent head and neck squamous cell carcinoma (HNSCC) as monotherapy in patients whose tumours express the biomarker PD-L1. The drug’s approval in combination with FU is for the treatment of the same condition, irrespective of PD-L1 expression.
The extended approval was driven by the findings of the phase 3 KEYNOTE-048 trial in which Keytruda significantly improved the overall survival (OS) in comparison to the EXTREME regimen (cetuximab with carboplatin or cisplatin plus FU). This was demonstrated with the drug used as monotherapy and in combination with chemotherapy.
The late-stage trial featured 882 patients with metastatic HNSCC who did not undergo any prior systemic therapy and whose condition was considered incurable by local therapies.
Keytruda was approved by the FDA initially in 2016 for recurrent or metastatic HNSCC in patients with disease progression on or after platinum-containing chemotherapy under the regulator’s accelerated approval process based on objective response rate data from the phase 1b KEYNOTE-012 study. Merck said that the data from the KEYNOTE-048 trial has resulted in the accelerated approval being converted to a full approval.
Merck Research Laboratories clinical research vice president Jonathan Cheng said: “Head and neck squamous cell carcinoma has historically presented many challenges to physicians and patients, including limited treatment options and physical and functional issues caused by the disease and its treatment.
“This approval is an important advance in the management of this devastating cancer. The results of KEYNOTE-048, which support this approval, demonstrated that Keytruda monotherapy for patients whose tumors expressed PD-L1 CPS greater than or equal to one and Keytruda in combination with chemotherapy regardless of PD-L1 expression significantly prolonged survival for patients with metastatic or with unresectable, recurrent head and neck squamous cell carcinoma in the first-line setting.”
Keytruda works by boosting the ability of the body’s immune system to help detect and fight tumour cells. The humanized monoclonal antibody blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2 to enable activation of T lymphocytes that may affect tumour cells and healthy cells.