Trulicity ® (dulaglutide)

This information is intended for UK registered healthcare professionals only as a scientific exchange in response to your search for information. Please refer to the link for full prescribing information: Trulicity Summary of Product Characteristics (SmPC)

Trulicity® (dulaglutide): Medullary Thyroid Carcinoma and C-Cell Hyperplasia

One case of MTC was reported in Trulicity (dulaglutide) clinical trials. This patient had a markedly elevated serum calcitonin level at baseline.

Preclinical Studies

In a 6-month carcinogenicity study in transgenic mice, there was no tumorigenic response. In a  2‑year carcinogenicity study in rats, at ≥ 7 times the human clinical exposure following 1.5 mg dulaglutide per week, dulaglutide caused statistically significant, dose‑related increases in the incidence of thyroid C‑cell tumours (adenomas and carcinomas combined). The clinical relevance of these findings is currently unknown.1

Glucagon-like peptide-1 receptor agonists have induced thyroid C-cell adenomas and carcinomas in mice and rats at clinically relevant exposures. Dulagutide causes a dose-related and treatment-duration-dependent increase in the incidence of thyroid C-cell tumors, such as adenomas and carcinomas, in rats after lifetime exposure.2

This finding was not replicated in a 6-month carcinogenicity study in rasH2 transgenic mice, nor in a 12-month study in monkeys.2,3

Non‑clinical data reveal no special hazards for humans based on conventional studies of safety pharmacology or repeat‑dose toxicity.1

Clinical Studies

There was no increased reporting of potential C-cell hyperplasia in dulaglutide-treated patients compared with placebo- or active-comparator-treated patients.4

There has been 1 report of MTC in a patient who received dulaglutide 2 mg for approximately 6 months in a study that was ongoing before the implementation of exclusion criteria and serial calcitonin monitoring. This cancer was assessed and determined to be preexisting.5,6

However, for rare diseases, like many cancers with long latency periods, the database is too small and duration of exposure too short to definitively conclude that there is no increased risk of malignancy. Eli Lilly and Company will continue to carefully assess for malignancies in ongoing studies and will continue to assess risk through postmarketing cases and exposure.4


MTC = Medullary Thyroid Carcinoma


1. Trulicity [summary of product characteristics]. Eli Lilly Nederland B.V., The Netherlands.

2. Byrd RA, Sorden SD, Ryan T, et al. Chronic toxicity and carcinogenicity studies of the long-acting GLP-1 receptor agonist dulaglutide in rodents. Endocrinology. 2015;156(7):2417-2428.

3. Vahle JL, Byrd RA, Blackbourne JL, et al. Effects of dulaglutide on thyroid C cells and serum calcitonin in male monkeys. Endocrinology. 2015;156(7):2409-2416.

4. Data on file, Eli Lilly and Company and/or one of its subsidiaries.

5. Skrivanek Z, Gaydos BL, Chien JY, et al. Dose-finding results in an adaptive, seamless, randomized trial of once-weekly dulaglutide combined with metformin in type 2 diabetes patients (AWARD-5). Diabetes Obes Metab. 2014;16(8):748-756.

6. Sherman SI, Kloos RT, Tuttle RM, et al. No calcitonin change in a person taking dulaglutide diagnosed with pre-existing medullary thyroid cancer [published online July 29, 2017]. Diabet Med.

Date of Last Review: October 03, 2017

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