# Lenvatinib-Induced Acalculous Cholecystitis—An Often-Unrecognized Toxicity: A Case Series and Literature Review

## TL;DR

This paper reports that Lenvatinib, a cancer drug, can cause gallbladder inflammation without gallstones, a side effect that may be under-recognized.

## Contribution

The study highlights that Lenvatinib-induced acalculous cholecystitis is more common than previously thought.

## Key findings

- Six patients on Lenvatinib showed signs of acalculous cholecystitis, either clinically or radiologically.
- A literature review suggests this toxicity is more frequent than indicated in initial drug studies.
- Oncologists should be aware of this under-recognized side effect and its management.

## Abstract

Lenvatinib is an oral oncology drug which is used for the treatment of several different cancer types such as kidney, uterine, liver, and thyroid cancer. We present a study of twenty-two (22) patients receiving Lenvatinib in our oncology center, in which three (3) patients developed both clinical and radiological features of cholecystitis (inflammation of the gallbladder) without the presence of gallstones, which is called acalculous cholecystitis. Another three (3) patients had radiological features of acalculous cholecystitis but without abdominal pain or other clinical symptoms of cholecystitis, which has also been described in the past. We finally undertook a review of similar Lenvatinib-induced acalculous cholecystitis studies published in the literature, and our findings suggest that this toxicity is not as rare as suggested by the Lenvatinib licensing studies, and that oncologists using Lenvatinib need to be made aware of this potential side effect and its management.

Lenvatinib is an oral multi-kinase inhibitor which is used for the treatment of renal cell carcinoma, non-iodine avid differentiated thyroid cancer, hepatocellular carcinoma, and endometrial cancer. We present a series of three (3) patients who, whilst on treatment with Lenvatinib, developed symptoms and radiological findings of acalculous cholecystitis. A radiological review of another nineteen (19) Lenvatinib-treated patients in our center was undertaken, with another three (3) patients exhibiting radiological features of acalculous cholecystitis with gallbladder wall thickening and pericholecystic fluid collection but without abdominal pain or clinical symptoms of cholecystitis. A literature review is also presented of all previous publications of Lenvatinib-induced acalculous cholecystitis, including the results of two pharmacovigilance studies. This review provides evidence that Lenvatinib-induced acalculous cholecystitis is not as rare as initially thought from the Lenvatinib licensing studies; hence, this is an adverse event that merits more attention. Oncologists using Lenvatinib should be aware of this potential toxicity and be familiar with its management.