Verzenios ® ▼ (abemaciclib)

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How to manage pneumonitis in Verzenios® ▼ (abemaciclib) treated patients?

Based on the grade of interstitial lung disease (ILD)/pneumonitis, abemaciclib dose modifications may be required as outlined below.


Pneumonitis and Abemaciclib


Pneumonitis is a general term that refers to inflammation of the lungs. The term interstitial lung disease (ILD) is an imprecise clinical term that refers to a group of more than 200 chronic lung disorders characterized by inflammation of the lung tissue, which often leads to scarring.1,2 

In clinical practice, the terms ILD and pneumonitis are often used interchangeably.

Interstitial lung disease can be caused by autoimmune diseases, genetic abnormalities (eg, Hermansky–Pudlak syndrome) and long-term exposures to hazardous materials (eg, medications such as bleomycin, occupational exposures such as asbestos, tobacco smoke, or agents in the environment that cause an immune reaction called hypersensitivity pneumonitis).

However, the cause of ILD is mostly unknown and the lung manifestations are described as idiopathic interstitial pneumonia.1

Drug-induced interstitial lung disease (DIILD) occurs when exposure to a drug causes inflammation and eventually fibrosis of the lung interstitium. 

DIILD has been associated with chemotherapeutic agents, antibiotics, antiarrhythmic drugs, and immunosuppressive agents.

Cancer drugs account for approximately 23% to 51% of DIILD cases.3 It becomes challenging to identify potentially causative agents in oncology when drugs are combined with other agents, or given in association with radiotherapy; the risk of developing DIILD may be increased when causative agents are combined.3

Mechanism of Action and Etiology of ILD

The reasons patients develop ILD/pneumonitis when they are taking anticancer medications are not fully understood. There can also be multiple confounding factors, especially in cancer treatment, where multiple drugs are often administered at the same time.

Based on the mechanism of action of abemaciclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor and the etiology of ILD, there is no known mechanistic explanation for an association of abemaciclib and ILD.4

Management Recommendations for ILD/Pneumonitis

Monitor patients for pulmonary symptoms that indicate ILD/pneumonitis and treat them appropriately.5

Permanently discontinue abemaciclib in patients with Grade 3 or 4 ILD/pneumonitis.5

Please find management recommendations for ILD/pneumonitis in Management recommendations for interstitial lung disease (ILD)/pneumonitis.

Management recommendations for interstitial lung disease (ILD)/pneumonitis5


Management recommendations

Grade 1 or 2

No dose adjustment required.

Persistent or recurrent Grade 2 toxicity that does not resolve with maximal supportive measures within 7 days to baseline or Grade 1

Suspend dose until toxicity resolves to baseline or Grade 1.

Resume at next lower dose.

Grade 3 or 4

Discontinue abemaciclib.


Incidence of Pneumonitis in the MONARCH Trials and Postmarketing Reports

Across the MONARCH clinical trials, the incidence of ILD/pneumonitis was

  • 2.3% in MONARCH 1
  • 2.0% in MONARCH 2, and
  • 5.2% in MONARCH 3.4,6

In the abemaciclib + fulvestrant arm (n=441) of MONARCH 2

  • 3 (0.7%) events were Grade ≥3
  • 4 (0.9%) events were reported as a serious adverse event (SAE)
  • there were no reported dose reductions, and
  • 2 (0.4%) discontinuations were reported due to ILD/pneumonitis events.6

In the abemaciclib + nonsteroidal aromatase inhibitor (NSAI) arm (n=327) of MONARCH 3

  • 4 (1.2%) events were Grade ≥3
  • 6 (1.8%) events were reported as an SAE
  • 2 (0.6%) patients required dose reductions due to an ILD/pneumonitis event, and
  • 4 (1.2%) patients discontinued due to an ILD/pneumonitis event.6

In the MONARCH 2 trial, out of 9 patients who received abemaciclib plus fulvestrant and experienced an ILD/pneumonitis event, 8 patient had lung metastases and 6 patients had prior radiotherapy. In the MONARCH 3 trial, out of 17 patients who received abemaciclib plus NSAI and experienced an ILD/pneumonitis event, 6 patients had lung metastases and 9 patients had prior radiotherapy.6

Deaths in the MONARCH Clinical Trials

Death due to ILD/pneumonitis in abemaciclib-treated patients was reported

  • in 1 patient in MONARCH 1
  • in 2 patients (0.5%) in MONARCH 2, and
  • in 1 patient (0.3%) in MONARCH 3.7

Incidence of Pneumonitis in Postmarketing Reports

Interstitial lung disease/pneumonitis was identified as a common (≥1.0% to <10%) adverse drug reaction based on spontaneous data from postmarketing reports.4

A meta-analysis, which included 12 randomized controlled studies, including 7 studies with abemaciclib, found the incidence of all-grade ILD/pneumonitis in patients treated with abemaciclib to be 2.5%.8


1Anthimopoulos M, Christodoulidis S, Ebner L, et al. Lung pattern classification for interstitial lung diseases using a deep convolutional neural network. IEEE Trans Med Imaging. 2016;35(5):1207-1216.

2Bourke SJ. Interstitial lung disease: progress and problems. Postgrad Med J. 2006;82(970):494-499.

3Skeoch S, Weatherley N, Swift AJ, et al. Drug-induced interstitial lung disease: a systematic review. J Clin Med. 2018;7(10).

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

5Verzenios [summary of product characteristics]. Eli Lilly Nederland B.V., The Netherlands.

6Rugo HS, Huober J, Garcia-Saenz JA, et al. Management of abemaciclib-associated adverse events in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer: safety analysis of MONARCH 2 and MONARCH 3. Oncologist. 2021;26(1):e53-e65.

7Verzenio [package insert]. Indianapolis, IN: Eli Lilly and Company; 2021.

8Zhang Y, Ma Z, Sun X, et al. Interstitial lung disease in patients treated with cyclin-dependent kinase 4/6 inhibitors: a systematic review and meta-analysis of randomized controlled trials. The Breast. 2022;62:162-169.

This medicinal product is subject to additional monitoring. This will allow quick identification of new safety information. Healthcare professionals are asked to report any suspected adverse reactions.

Date of Last Review: 10 March 2022

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