Larotrectinib Displays Tolerability in Thyroid Cancer and Other Solid Tumors

Theodore W. Laetsch, MD, an attending physician at the Cancer Center at Children’s Hospital of Philadelphia, discusses the safety profile of larotrectinib (Vitrakvi) in thyroid cancer and other solid tumors.

According to Laetsch, larotrectinib, a tyrosine kinases (TRK) inhibitor, is associated with certain neurological toxicity such as fatigue and dizziness. This is common among this class of agents related to TRK inhibition. If therapy is discontinued, pain at the time of withdrawal could last for several days, according to Laetsch.

In pediatric patients, mild elevations in liver function tests could occur. Additionally, mild cytopenias, most commonly neutropenia, are also associated with the agent.

0:08 | Larotrectinib is a TRK inhibitor. And so, some of the adverse events that we see are part of this class of agents and related to TRK inhibition, and those include some neurologic adverse events like fatigue and dizziness. We also will occasionally see patients when we discontinue this therapy, will have some pain at the time of withdrawal that can last for several days, again, but to be due to inhibition of the TRK receptor. Some patients will have dizziness. We see some potentially off target effects, meaning not clearly related to inhibition of the TRK receptor. In children, the most common of these are mild elevations in liver function tests and mild cytopenias, neutropenia most commonly.