Keytruda Shows Hint of Major Added Benefit for Patients With Squamous Cell Carcinoma

The median survival time for individuals with SCC and treated with Merck’s pembrolizumab was 13.9 months compared with 8.8 months in the control arm.

Early benefit assessments of pembrolizumab (Keytruda, Merck) showed that there is a hint of major added benefits for individuals with advanced squamous cell carcinoma (SCC) of the esophagus, according to the German Institute of Quality Efficiency in Health Care (IQWiG).

However, an added benefit for individuals with advanced adenocarcinoma has not been proven.

Pembrolizumab in combination with fluoropyrimidine- and platinum-based chemotherapy is approved for first-line treatment of individuals with locally advanced, metastatic, or unresectable SCC or adenocarcinoma of the esophagus with PD-L1-expressing tumors.

Few therapies used so far could prolong survival, so the goal is to instead fight symptoms for a few months offering as high a quality of life as possible, according to investigators

SCC, HER2-negative adenocarcinoma, and rare HER2-positive adenocarcinoma are the 3 most common forms of esophageal cancers.

The growth factor receptor inhibits cell death and makes tumors producing it insensitive to chemotherapy alone.

Data were submitted from the KEYNOTE 590 study for the first patient group, and additional data from the KEYNOTE 062 study were presented for the second group. No data have been presented for the third group.

From the data, indications of greater or lesser benefit can be derived, because the exact treatment regimen in the studies remains unclear and usable data on patient outcomes are lacking.

Additionally, data from both studies suggest no effect on the overall survival and no clinically relevant difference in the other outcomes for individuals with HER2-negative adenocarcinoma.

There are also no evaluable study data for those with HER-2 positive adenocarcinoma.

However, for SCC, the median survival time for individuals was 13.9 months with the new treatment compared with the 8.8 months in the control arm.

The results suggest a hint of a major advantage that is not challenged by the immune-related serious adverse events. However, a conclusion on the health-related quality of life could not be drawn.

Additionally, there is a hint of a major added benefit of pembrolizumab in combination with fluoropyrimidine- and platinum-based chemotherapy compared with cisplatin and 5-fluorouracil for the first-line treatment of locally advanced or metastatic not curatively treatable SCC of the esophagus.

“In 10 years of early benefit assessment, this is the first time we have seen a new drug for this indication in the first line," Volker Vervölgyi, head of the oncology division in IQWiG's drug assessment department, said in a statement. “The clear prolongation of overall survival in esophageal squamous cell carcinoma is gratifying.”

The dossier assessment is part of the early benefit assessment according to the Act on the Reform of the Market for Medicinal Products, and, after publication, the Federal Joint Committee will conduct a commenting procedure to make a final decision on the extent of the benefit.

Cancer in the esophagus can be triggered by alcohol, reflux acid, or smoking and often goes unnoticed. This results in more advanced cancer by the time of diagnosis, where and metastases may have already formed.

Reference

Pembrolizumab in combination with chemotherapy: major added benefit in advanced squamous cell carcinoma of the oesophagus. EurekAlert. News release. February 28, 2022. February 25, 2022. https://www.eurekalert.org/news-releases/944584