Pembrolizumab as a first-line treatment for adults with advanced lung cancer

In 2017, the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) looked into the advantages and disadvantages of pembrolizumab (trade name: Keytruda) as a first-line treatment for adults who have a non-small-cell lung cancer tumor that is producing elevated levels of the protein PD-L1. The manufacturer submitted one relevant study to IQWiG, providing at least preliminary answers to a number of questions.

A total of 305 people were involved in this study, and the data from 216 people was relevant for this assessment. Half of the people in the study were given pembrolizumab, and the other half had platinum-based chemotherapy. The study only involved people whose general health was still comparatively good despite having advanced cancer.

No data was provided for people in poorer general health who were no longer able to work.

What are the advantages of pembrolizumab?

Life expectancy: The study suggests that pembrolizumab has an advantage here. Half of the people in the group who had platinum-based chemotherapy had passed away within about 13 months. Those patients who had treatment with pembrolizumab lived an additional 6 months on average.

Health-related quality of life: The study suggests that pembrolizumab has an advantage for some aspects of quality of life, including:

  • Physical functioning: Patients who had treatment with pembrolizumab were able to manage everyday activities such as grocery shopping, eating or doing the laundry for a longer time than those who had the chemotherapy.
  • Role functioning: It took longer for patients who took pembrolizumab to feel limited by their condition in everyday life, recreational activities or at work.
  • Social functioning: Compared to those who had chemotherapy, the patients who took pembrolizumab felt less limited in their family life, activities with friends and other social activities.

There was no evidence of a difference in other aspects of health-related quality of life such as concentration, memory or mood.

Serious side effects: During the study, serious side effects with pembrolizumab occurred later: According to one preliminary estimate, half of the patients experienced severe side effects within about 8 months. In patients who had chemotherapy, this was the case after about one month.

Loss of appetite, nausea, vomiting and constipation: The study showed an advantage for pembrolizumab regarding these problems. They occurred later in people who used it: Half of them had experienced symptoms like nausea and vomiting within about 16 months. This was already the case within nearly 5 months when chemotherapy was used.

Pembrolizumab also had an advantage in terms of the following side effects:

  • Trouble swallowing
  • Sore mouth
  • Breathing problems
  • Hair loss

What are the disadvantages of pembrolizumab?

Immune-mediated side effects: The analysis of data from all 305 participants suggests that the new drug has a disadvantage here compared with the standard treatments. Treatment with pembrolizumab resulted in considerably more immune-mediated side effects than chemotherapy. Immune-mediated side effects are medical conditions in which the immune system attacks the body's cells. This may lead to things like inflammatory changes affecting the body's organs.

No difference

Pain, exhaustion, insomnia, diarrhea and coughing: No difference between the treatments was found regarding these symptoms.

General health: There was no discernible difference in terms of general health, either.

Treatment stopped due to side effects: There was no difference between the treatments here.