Side Effect: Inflammation of the Lungs (Pneumonitis)

What is Inflammation of the Lungs (Pneumonitis)?

Inflammation of the lungs, otherwise known as pneumonitis, is a condition characterized by inflammation to the lung tissue.

What does Inflammation of the Lungs (Pneumonitis) look like?

The gold standard for diagnosing inflammation of the lungs is imaging with a computed tomography (CT) scan. Depending on the cause of the lung inflammation, the radiographic features on the CT scan can vary. Patients with inflammation of the lungs may have new or worsening cough, shortness of breath, increased oxygen requirement, chest pain, or fevers.

Who gets Inflammation of the Lungs (Pneumonitis)?

Inflammation of the lungs can occur as an immune-related adverse event (irAE) in patients with cancer who are receiving immune checkpoint inhibitor (ICI) therapy such as:

PD-1 inhibitors:

• Pembrolizumab (Keytruda®)
• Nivolumab (Opdivo®)
• Cemiplimab (Libtayo®)
• Dostarlimab (Jemperli®)
• Retifanlimab (Zynyz®)
• Toripalimab (Loqtorzi®)

PD-L1 inhibitors:

• Atezolizumab (Tecentriq®)
• Durvalumab (Imfinzi®)
• Avelumab (Bavencio®)

CTLA-4 inhibitors:

• Ipilimumab (Yervoy®)
• Tremelimumab (Imjudo®)

PD-1 inhibitor + LAG-3 inhibitor:

• Nivolumab + relatlimab (Opdualag®)

ICIs activate the immune system against cancer cells, but they can also trigger an immune response against healthy tissues, including lung tissue, leading to pneumonitis. ICIs can cause pneumonitis when used alone, but the incidence can be higher when two ICI therapies are combined such as a PD-1 inhibitor and CTLA-4 inhibitor.

Other chemotherapy treatments can also cause pneumonitis, examples include mTOR inhibitors (everolimus (Afinitor®), temsirolimus (Torisel®)), gemcitabine (Gemzar®), osimertinib (Tagrisso®) and trastuzumab deruxtecan (Enhertu®). Inflammation of the lungs can also occur as a result of graft-versus-host disease (GVHD) after an allogeneic stem cell transplant, after radiation to the chest, or infections.

How to prevent Inflammation of the Lungs (Pneumonitis)

Preventing pneumonitis in patients with cancer can be challenging. Patients should be carefully screened before starting treatment to identify any preexisting conditions that could increase the risk of lung inflammation. During treatment, patients should be monitoring closely for any signs or symptoms of lung inflammation. Patients should be educated about the signs and symptoms of lung inflammation and advised to seek medical attention promptly if they experience any of these symptoms.

How to treat Inflammation of the Lungs (Pneumonitis)

Treatment of lung inflammation in patients with cancer typically requires stopping the treatment that is causing the inflammation and using medications to control symptoms and reduce inflammation. Mild cases may be treated outpatient with oral steroids such as prednisone (Deltasone®). More severe cases may require hospitalization and use of intravenous corticosteroids such as methylprednisolone (Solu-Medrol®), or other anti-inflammatory medications such as infliximab (Remicade®), immune globulin (IVIG), or mycophenolate mofetil (Cellcept®). Supplemental oxygen might be required for those that are not breathing in enough oxygen on their own.