Rematch.

Top Line: Immune checkpoint inhibitors (ICI) have proven to be game-changers in several malignancies.

The Study: At the same time, they have changed the face of therapeutic toxicity. Fortunately, the WHO has been collecting drug safety reports for over half a century. Here’s a retrospective look at ICI-related adverse events (AE) spanning 1967 to 2019 (hereinafter the U.S-funded era). The primary question was the rate of ICI-AEs recurrences with re-challenge of said ICI. Now, finding ICI-AEs wasn’t hard. There were over 24K cases, among which just over 6K (25%) were associated with an ICI-rechallenge. Importantly, this only provides data on cases with AEs so this can’t inform the rate of AE among all rechallenges. But, among the rechallenged ICI-AEs with sufficient clinical information, only 29% were the same AE that caused discontinuation of the ICI in the first place. Hepatitis (OR 3.4), pneumonitis (OR 2.3), and colitis (OR 1.8) were most likely to recur with a rechallenge while adrenal events (OR 0.3) were least likely.

TBL: It seems that recurrence of an ICI-related adverse event upon rechallenge with ICI isn’t inevitable or even that likely. | Dolladille, JAMA 2020