Real-world treatment patterns and clinical outcomes in patients with radioiodine-refractory differentiated thyroid cancer (RAI-R DTC) treated with first line lenvatinib monotherapy in the United States

Abstract

Purpose Lenvatinib was approved for the treatment of patients with radioiodine-refractory differentiated thyroid cancer (RAI-R DTC) in the United States (US) in 2015. The main objective of the current study was to assess real-world clinical effectiveness in RAI-R DTC patients treated with first line lenvatinib monotherapy in the US. Methods A retrospective chart review was conducted in RAI-R DTC patients who initiated lenvatinib monotherapy as first line treatment between February 2015 and September 2020. Anonymized data were abstracted by prescribing physicians from individual patient’s electronic health records. Clinical outcomes included provider-reported real-world best overall response (rwBOR), real-world progression-free survival (rwPFS), and overall survival (OS). Time-to-event endpoints were assessed using Kaplan–Meier methods. Results Our study included 308 RAI-R DTC patients treated with first line lenvatinib. At lenvatinib initiation, patients’ median age was 60 years, 51.6% were female, and 26.0% of patients had an ECOG performance score of ≥2. Over the follow-up period, 32.5% of patients discontinued first line lenvatinib permanently, with others remaining on treatment. The median duration of lenvatinib therapy was 17.5 months overall. Provider-reported rwBOR (complete or partial response) to lenvatinib was 72.4%. Median rwPFS was 49.0 months. Estimated rwPFS rates at 24 and 48 months were 68.5% and 55.0%, respectively. Estimated OS rates at 24 and 72 months were 78.4% and 57.0%, respectively; median OS was not reached. Conclusion The current study reinforces the clinical effectiveness of first line lenvatinib as standard of care in patients with RAI-R DTC in real-world clinical practice in the US.

Current Advances in Radioactive Iodine Refractory Differentiated Thyroid Cancer

“…The risk of RAIR-DTC can raise in elderly patients with aggressive histological DTC subtype and with presence of metastatic disease at the time of diagnosis. In these patients, cancer heterogeneity increases with RAI uptake inhomogeneity into target lesions so RAI therapy can be less effective [3,20]. The prevalence of RAIR-DTC approximately amounts of 15% of DTC patients, particularly those with distant metastases at diagnosis and older age.…”

“…While differentiated thyroid cancer (DTC) patients have an outstanding overall long-term survival rate, certain subsets of DTC patients have a very high likelihood of disease recurrence [1][2][3]. To evaluate the likelihood of recurrent or chronic illness in DTC patients, the American Thyroid Association (ATA) initial risk classification system has been proposed.…”