Review Discusses Pneumonitis as an Adverse Effect of Checkpoint Inhibitors

Research published by Cancer Management & Research explores the efficacy of treating multiple malignancies with immune checkpoint inhibitors and programmed cell death-1 inhibitors (PD-1). The review specifically analyzes the presence of pneumonitis as an adverse event following treatment of checkpoint inhibitors.

The immune checkpoint inhibitors are intended to target cytotoxic T-lymphocyte antigen 4 (CTLA-4) and PD-1, in order to block negative T-cell regulators and promote antitumor immune activity. Pneumonitis is one of the potential life-threatening immune-relate adverse events (irAEs) that are associated with checkpoint inhibition.

When reviewing the epidemiology of checkpoint inhibitor-related pneumonitis (CIP), the researchers discussed the rare occurrences of CIP. In a clinical trial, there was a less than 5% occurrence in patients treated with a monotherapy and a slightly greater than 5% incidence of those treated with a combination therapy.

Pneumonitis is less common among patients with anti-CTLA-4 treatment than those with anti-PD-1 treatment, according to the review. The risk of the adverse effect disease also may be influenced by the tumor type and greater in patients with non-small cell lung cancer. However, there are no specific or direct patient risk factors that can be determined for those that develop the pneumonitis.

An early diagnosis of CIP contributes to the efficacy of the necessary treatment. Grade 2 pneumonitis can often be treated with steroids, as they do not affect the efficacy of the immunotherapy. Grade 3/4 pneumonitis patients however, should be admitted to a hospital due to the severity of their symptoms and the life-threatening risks. The review also suggests that not who experience moderate to severe pneumonitis stop receiving their checkpoint inhibitor doses.

“The introduction of the immune checkpoint inhibitors has reinvigorated the management of a number of malignancies. Anti-CTLA-4 and anti-PD-1 agents have demonstrated marked efficacy in the treatment of advanced cancers and have shed light on new tumor biologic and immunologic principles,” concluded the review. “Nonetheless, immunotherapy is associated with rare but potentially life-threatening irAEs. The widespread use of these agents demands a greater understanding of the clinical manifestations, diagnosis, and treatment of these side effects.”