SUMMARY OF THE STUDY
The SELECT study included 392 patients with thyroid cancer not responding to radioactive iodine therapy and progressing within the previous 13 months. Patients were randomly assigned 2:1 to receive 24 mg of oral lenvatinib daily (261 patients) or no drug (placebo, 131 patients) until the cancer started to progress, the patients developed an unacceptable toxicity to the treatment, or the patients withdrew from the study. The data collected prior to November 15, 2013 was used for the initial analysis. After this, the patients in the placebo group who had progressive cancer could choose to receive lenvatinib treatment.
Additional data collected over the next three years until September 1, 2016 was used for the current study. A total of 157 patients (60%) had a complete or partial response to the levantinib treatment. The patients who responded to lenvatinib had stable disease for an average of 30 months. The duration of the response to treatment appeared to be shorter in patients with large cancer and for patients with spread of the cancer to the liver or brain. The duration of the response to treatment was similar for patients who had received one prior cancer therapy and those who had never received therapy prior to the study. A total of 80% of lenvatinib-treated patients experienced serious treatment-related adverse events, most of them occurring early in the course of treatment.
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This updated analysis confirmed that lenvatinib can delay the progression of thyroid cancer in patients not responding to radioactive iodine therapy and further showed that the patients who responded to lenvatinib could have a prolonged, durable effect, lasting for approximately 30 months. More than half of patients may respond to this treatment. Since most patients experienced side effects from the levantinib, early recognition and adequate treatment of the side effects is especially important to allow treatment continuation.
— Alina Gavrila, MD, MMSC