While clinical trials were promising, they don’t always reflect how a treatment performs in real-world settings. Moreover, patients come from diverse backgrounds and may have health-related issues that prohibit them from clinical trial participation. To understand lenvatinib’s real-world impact, Professor Francis Worden of the University of Michigan and colleagues reviewed medical records from 308 patients treated with lenvatinib between 2015 and 2020 throughout the entire United States.

Overall, the study results were encouraging: the median PFS was 49 months, meaning patients may live with their disease for extended periods of time. Overall survival was also notable: more than 78% of patients were alive two years after starting treatment, and 57% were still living at six years.

As expected with many real-world experiences, outcomes surpass those observed from previous clinical trial results. Notably, Prof. Worden and colleagues learned that clinicians were treating patients with the appropriate starting dosage allowing for excellent responses to treatment. Moreover, the reported overall response rate (patients whose tumors decreased in size by 30% or more) was 79%, meaning that the vast majority had tumor shrinkage, which likely led to improvements in symptoms. 

As all with tyrosine kinase inhibitors, lenvatinib can cause side effects such as high blood pressure, fatigue, and weight loss. However, most patients were able to manage these issues without stopping treatment. Maintaining patients on effective doses and managing side effects were key.

Importantly, this study included patients from varied underserved backgrounds, many of whom are often excluded from clinical trials, making the findings more applicable to everyday practice. It also confirmed that patients with limited resources are still treated effectively, despite perceptions that such patients may have limited medical access.

While retrospective studies have limitations, this research underscores how real-world data can validate and expand upon clinical trial results. Lenvatinib has emerged as the most important drug for patients with radioiodine-resistant thyroid cancer, offering not just more time, but also improving symptomatic disease burden that may enhance quality of life.