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

In 2016, the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) looked into the advantages and disadvantages of pembrolizumab (trade name: Keytruda) for adults who have lung cancer with a PD-L1 protein mutation. The drug manufacturer provided IQWiG with one relevant study. The study involved only patients who had already had

  • chemotherapy or
  • treatment targeting the epidermal growth factor receptor (EGFR) or the enzyme called anaplastic lymphoma kinase (ALK).

Data from about 690 people in this study was relevant for this assessment. Half of the people in the study were given pembrolizumab, and the other half used the standard treatment docetaxel. The manufacturer did not provide any studies comparing the new treatment with other standard treatments, such as pemetrexed, nivolumab or supportive care.

What are the advantages of pembrolizumab?

Life expectancy: The study suggests that pembrolizumab has an advantage here: Half of the patients who had been given pembrolizumab had passed away within about ten and a half months. And half of the patients who used the standard treatment docetaxel had already died within eight and a half months.

Hair loss and mouth sores: The study offered weak evidence of an advantage for pembrolizumab in terms of these symptoms. Nearly 11 out of 100 people in the pembrolizumab group experienced hair loss, compared with 59 out of 100 people in the docetaxel group. Mouth and tongue sores affected about 22 out of 100 people who took pembrolizumab, and nearly 32 out of 100 people in the standard treatment group.

Disorders of the nervous system: There was weak evidence of an advantage for pembrolizumab here too. Nearly 28 out of 100 people who took pembrolizumab had nervous system disorders, compared with 35 out of 100 people who used docetaxel.

Severe side effects: The study also showed weak evidence that pembrolizumab has a benefit in terms of serious side effects. Nearly 47 out of 100 people who took pembrolizumab had serious side effects, compared to 56 out of 100 people who used docetaxel. There was also weak evidence of a benefit concerning serious side effects such as infections and diseases of the blood and lymphatic system.

Treatment stopped due to serious side effects: There was also weak evidence of an advantage related to treatment being stopped due to side effects: About 8 out of 100 people in the pembrolizumab group stopped the treatment due to side effects, compared to nearly 14 out of 100 in the docetaxel group.

Side effects: The study provided weak evidence of an advantage for pembrolizumab over docetaxel in terms of the following side effects:

  • Gastrointestinal (stomach and bowel) problems
  • Problems where the infusion needle is inserted into the skin
  • Diseases affecting the skin and subdermis

What are the disadvantages of pembrolizumab?

Immune-mediated side effects: The study showed weak evidence that pembrolizumab has a disadvantage in terms of immune-mediated side effects when compared with the standard treatment. 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. Serious immune-mediated side effects occurred in about 6 out of 100 people who used pembrolizumab, and in about 1 out of 100 people who used docetaxel.

No difference

Health-related quality of life: No difference was found between the treatments here. There were also no differences concerning the following problems:

  • Exhaustion
  • Insomnia
  • Pain
  • Loss of appetite
  • Diarrhea
  • Nausea and vomiting
  • Trouble swallowing
  • Constipation
  • Coughing and coughing up blood
  • Breathing problems

What remains unanswered?

General health: The manufacturer did not provide any suitable data about how people in the study assessed their own general health.