Pembrolizumab (Keytruda) used on its own for the treatment of advanced, incurable head and neck cancer

In 2020, the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) looked into whether pembrolizumab has any advantages or disadvantages compared to the standard treatment for squamous cell carcinoma of the head and neck – either in adults whose cancer has returned and can’t be operated on, or those whose cancer has formed tumors elsewhere in the body (metastasis). In addition, the cancer cells must have the protein PD-L1.

The data of over 500 patients in one study was analyzed for this assessment: 257 participants were given pembrolizumab, and 255 participants had a standard treatment of cetuximab and platinum-based chemotherapy.

This is what was found:

What are the advantages of pembrolizumab?

Life expectancy: Early results suggest that pembrolizumab can increase the life expectancy of patients whose cancer has spread to other parts of the body. There was no difference here in patients who had a recurrence, though.

Severe side effects overall: Early results suggest that pembrolizumab has an advantage here. About 55 out of 100 people who were given pembrolizumab had severe side effects, compared to about 83 out of 100 people who had cetuximab and chemotherapy.

These severe side effects included:

  • Skin diseases
  • Disorders of the blood and lymphatic system
  • Anemia
  • Stomach and bowel (gastrointestinal) diseases
  • Inflammation of the mucous membranes
  • Severe magnesium deficiency

Treatment stopped due to side effects: Early results also suggest that pembrolizumab has an advantage here. About 8 out of 100 people who were given pembrolizumab stopped the treatment due to the side effects, compared to about 33 out of 100 people who had cetuximab and chemotherapy.

Early results also suggest that pembrolizumab has an advantage over the combination of cetuximab and chemotherapy in terms of the following side effects:

  • Diseases of the ear
  • Exhaustion (asthenia)
  • Dizziness
  • Infection of the skin near the nails (paronychia)

What are the disadvantages of pembrolizumab?

According to early results, pembrolizumab has disadvantages in terms of severe respiratory diseases. About 13 out of 100 people who were given pembrolizumab had this severe side effect, compared to about 7 out of 100 people who received cetuximab and chemotherapy.

No difference

General health: The patients in the study were asked how they would assess their own health. There was no difference between the two treatment groups.

The study showed no difference between the two treatment groups regarding immune-mediated side effects. Immune-mediated side effects are diseases in which the immune system attacks your own body.

What remains unanswered?

Cancer symptoms: The manufacturer didn’t provide any usable data on disease-related symptoms such as exhaustion, problems sleeping, trouble swallowing or pain.

Health-related quality of life: There was no usable data on health-related quality of life.