Pembrolizumab (trade name: Keytruda) has been approved in Germany since September 2018 for the treatment of squamous cell carcinoma of the head and neck in adults whose cancer has come back (recurrence) or spread to other parts of the body (metastasis). Pembrolizumab is a treatment option if the tumor cells have a particular mutation that leads to a reduced immune system response. It can then be used in two groups of patients:

  • Patients in whom platinum-based chemotherapy is not effective enough. Then pembrolizumab is an option for second-line treatment.
  • Patients who have cancer that can’t be healed because it has led to metastatic tumors or has returned and surgery is not possible. Then pembrolizumab is an option for first-line treatment, either alone or in combination with chemotherapy.

Head and neck cancer includes tumors in the:

  • Mouth
  • Throat
  • Larynx (voice box)
  • Nose and sinuses
  • Neck
  • Thyroid gland

This type of cancer usually develops in the skin or mucous membranes through malignant changes in cells in the outer layer of skin (squamous cell carcinoma).

The symptoms can vary a lot depending on where the cancer is located. In the mouth the cancer typically causes swelling or growths, while cancer of the throat often causes problems with swallowing. If the voice box is affected, you may also experience chronic hoarseness or the feeling that something is stuck in your throat. This kind of cancer is more common in people over the age of 60.

Some head and neck tumors have higher levels of the protein PD-L1. This protein weakens the body's immune response against the tumor cells.

Pembrolizumab blocks the effect of the PD-L1 protein produced by the cancerous tissue, which is believed to inhibit the growth of the cancer.


Pembrolizumab is given directly into the bloodstream through an infusion (an IV drip) every three weeks. Each infusion contains 200 mg pembrolizumab and lasts about 30 minutes.

This treatment is stopped if severe side effects occur or if the cancer continues to progress.

As first-line treatment, pembrolizumab can either be used alone or in combination with chemotherapy.

Other treatments

Various, individually adjusted treatments with medication can be considered for adults who have already had treatment for squamous cell carcinoma of the head and neck. Examples of such second-line treatments include chemotherapy with methotrexate, or radiotherapy. Surgery is also an option.

The first-line treatment options for squamous cell carcinoma of the head and neck that can’t be cured include various combinations of chemotherapy, chemoradiotherapy, radiotherapy and antibodies for cancer immunotherapy.


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 current standard treatments for advanced squamous cell carcinoma of the head and neck with high levels of the protein PD-L1.

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More information

This information summarizes the main results of a review produced by the Institute for Quality and Efficiency in Health Care (IQWiG, Germany). The review was commissioned by the German Federal Joint Committee (G-BA) as part of the “early benefit assessment of medications.” On the basis of the reviews and the hearings received, the G-BA passed a resolution on the added benefit of pembrolizumab (Keytruda) when used alone and in combination with other treatments.