Researchers established that 21.1% of patients experienced a complete response (the disappearance of all signs of cancer from treatment) and 53.7% had a partial response (a decrease in tumor size or extent of the disease in the body from treatment), resulting in an overall response rate (the percentage of patients with either a partial or complete response to treatment) of 74.8%. The estimated PFS rates at 24 months for those experiencing complete response was 95.5% and 57.3% had partial response. At 24 months the estimated OS rate was not reached for those who experienced complete response and 84.4% for those with partial response. Of note, when OS is not reached in a study, it means that at least half of patients were still alive at the time the data were analyzed. In addition, 21.4% of patients had stable disease (neither grows nor shrinks), 3.3% experienced disease progression and 0.6% were not recorded.
The median duration of treatment was 16.8 months and the median follow-up period was 17.9 months. Lenvima was administered once daily at a starting dose of 24 mg for 60.2% of patients, 20 mg for 24%, 18 mg for 12.2% and 14 mg for 3.6%.
“The main goal of this data collection was to assess the clinical effectiveness [of Lenvima] in real-world data from the patient population of radioiodine-refractory cases from different European countries, the UK and Canada,” Locati said.
SELECT Trial Results
In the phase 3, randomized, double-blind, multicenter SELECT trial, median PFS was longer in the Lenvima group at 18.3 months versus 3.6 months in the placebo group.
The response rate was 64.8% in the Lenvima group (including four complete and 165 partial responses) versus 1.5% in the placebo group. The median OS was not reached in either group.
Common treatment-related adverse effects in the Lenvima group included high blood pressure (67.8%), diarrhea (59.4%) and fatigue (59%). Lenvima led to discontinuation in 14.2% of patients versus 2.3% in the placebo group and six out of 20 deaths in the Lenvima group during the treatment period were drug related.
Patient Demographics
The retrospective patient chart review included 337 patients with RAI-R DTC who started first-line (initial treatment) Lenvima monotherapy on March 26, 2015, in Europe, or August 9, 2016, in Canada, until January 31, 2022. Lenvima was approved in Europe in 2015 and in Canada in 2016.
Regarding patient disease characteristics, 60.2% of patients had stage 3 or 4 disease with the following thyroid cancer types: follicular (51%), papillary (45.7%) and Hurthle cell (3.3%). In total, 98.8% of patients reported with metastases (the spreading of cancer) in various locations: 50.4% in the lymph nodes, 48.1% in the lung, 47.5% in the bone and 21.2% in the liver.
The majority (67.1%) of patients had an ECOG performance status score of 0 (meaning completing daily tasks entirely independently) or 1 (patients were able to complete most daily tasks independently) and 21.1% with 2 (patients were limited in activities) or greater. This was a key difference from the SELECT trial which did not include those with a performance status of 2 or greater, Locati noted. Other differences from the SELECT trial included specific criteria for RAI-refractory status, disease progression evidence and prior treatment with tyrosine kinase inhibitors, the researchers noted.
The study included patients from Canada (16.9%), France (16.3%), Germany (16.6%), Italy (17.8%), Spain (17.5%) and the United Kingdom (14.8%). Data was provided by 91 clinicians who are either medical or clinical oncologists (71.4%) or endocrine oncologists (22%).
“We recognize some limitations of this study: the lack of complete safety data, short follow-up period and real-world variation in clinical outcomes,” Locati concluded.
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