immune checkpoint inhibitor

American

[ih-myoon chek-point in-hib-i-ter] / ɪˈmyun ˈtʃɛkˌpɔɪnt ɪnˌhɪb ɪ tər /

Also checkpoint inhibitor

noun

Immunology, Pharmacology.

a drug that targets and blocks certain proteins produced by T cells and other immune system cells in order to minimize the proteins’ restraints on cell activity, thereby freeing those cells to kill cancer cells more effectively.

Etymology

Origin of immune checkpoint inhibitor

First recorded in 1970–75

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Anktiva, in combination with an immune checkpoint inhibitor, received accelerated approval in Saudi Arabia earlier this year for the treatment of metastatic non-small-cell lung cancer.

From Barron's • Mar. 24, 2026

However, current immune checkpoint inhibitor drugs are extremely expensive and can cause significant side-effects.

From Science Daily • Dec. 10, 2025

"Cutaneous melanoma, which affects the skin, is the poster child of immunotherapy. It responds incredibly well to immune checkpoint inhibitor drugs," said Kammula.

From Science Daily • Apr. 16, 2024

Durvalumab, an immune checkpoint inhibitor targeting PD-L1, has previously been approved for treating specific patients with biliary tract cancer, liver cancer, small cell lung cancer and NSCLC.

From Science Daily • Oct. 23, 2023

A study from 2021 found a high TMB could predict whether patients would respond well to a type of immune checkpoint inhibitor known as pembrolizumab.

From Science Magazine • Oct. 4, 2022

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023