Semaglutide unexpectedly resolved withdrawal-like symptoms from the cancer drug larotrectinib | Research

The takeaway

A patient experiencing twice-daily withdrawal-like symptoms (myalgias, arthralgias, light sensitivity) from long-term larotrectinib therapy had complete resolution after starting semaglutide, suggesting GLP-1 agonists may modulate TRK-related pain pathways.

Complete resolution
Seven years of twice-daily withdrawal symptoms from cancer drug larotrectinib completely resolved after starting semaglutide

What the researchers found

Long-standing twice-daily withdrawal symptoms from larotrectinib (myalgias, arthralgias, photosensitivity occurring 30-45 min before doses) completely resolved after semaglutide initiation in a patient with >7 years of TRK inhibitor therapy.

Why it matters

About one-third of patients on TRK inhibitors experience withdrawal-like symptoms that significantly impact quality of life. If GLP-1 agonists can reliably resolve these symptoms, it would improve tolerability of an important cancer therapy.

The numbers in context

Patient: 35-year-old male with metastatic ETV6-NTRK3 parotid gland cancer. Larotrectinib for 7+ years with complete response. Daily myalgias and arthralgias 30-45 min before next dose. Complete resolution after starting semaglutide.

How the study worked

Single case report documenting clinical timeline of larotrectinib withdrawal symptoms and resolution with semaglutide.

Who was studied

One adult male with NTRK fusion cancer on long-term larotrectinib

What this study cannot tell us

Single case report. No controlled comparison. Cannot establish causation—symptoms may have resolved coincidentally. Mechanism is speculative. Reproducibility unknown.

How to read the evidence

Single case report—lowest evidence level. Intriguing observation requiring prospective validation.

When this study was published

Published in 2025; reports a novel and unexpected drug interaction.

The bigger picture

This unexpected finding highlights that GLP-1 receptors may interact with neurotrophic signaling pathways in ways not previously appreciated. As both TRK inhibitors and GLP-1 agonists become more widely used, understanding their interaction could open new therapeutic applications.

Questions still open

Would semaglutide help other TRK inhibitor patients with withdrawal symptoms?
What is the mechanism by which GLP-1 activation reduces TRK-related pain?
Could other GLP-1 agonists achieve the same effect?

Common questions

What are TRK inhibitor withdrawal symptoms?

About one-third of patients taking TRK inhibitors (like larotrectinib) for cancer experience withdrawal-like symptoms including muscle pain, joint pain, and light sensitivity when doses are missed, delayed, or wearing off. These occur because TRK pathways are involved in pain signaling.

How might semaglutide help with these symptoms?

The exact mechanism is unclear, but GLP-1 receptors are found in the nervous system and may interact with the neurotrophic pathways that TRK inhibitors target. By modulating these pathways, semaglutide might reduce the pain signals that cause withdrawal-like symptoms between doses.

Read the original research

Larotrectinib-associated withdrawal symptoms resolved following initiation of GLP-1 receptor agonist: a case report.

Cancer chemotherapy and pharmacology, 95(1), 102

View on PubMed ↗Publisher’s paper ↗

Citation

Patel, Reema; Deeken, John F. (2025). Larotrectinib-associated withdrawal symptoms resolved following initiation of GLP-1 receptor agonist: a case report.. Cancer chemotherapy and pharmacology, 95(1), 102. https://doi.org/10.1007/s00280-025-04829-x