BACKGROUND: LEN is approved for RR-DTC at a starting dose of LEN 24 mg/d (LEN24). In the phase 2 Study 211, a starting dose of LEN 18 mg/d (LEN18) did not show noninferiority vs LEN24 for objective response rate at week (wk) 24; safety as of wk 24 was similar in both arms. We report the impact of LEN treatment on HRQoL, a secondary objective of Study 211.
METHODS: Pts with RR-DTC were randomly assigned to a starting dose of LEN18 (n = 77) or LEN24 (n = 75). HRQoL was assessed at baseline, every 8 wks until wk 24, then every 16 wks, and at the off-treatment visit, using EQ5D and FACT-G instruments. Mean change from baseline scores and times to first and definitive deterioration were evaluated. Minimally important difference (MID) thresholds herein were 0.08 points for the health utilities index (HUI), and 7 points for the visual analog scale (VAS) and FACT-G. Analyses for any individual HRQoL outcome included all pts with valid data for that outcome. All statistics are nominal and descriptive.
RESULTS: Baseline EQ5D, FACT-G scores, and overall changes from baseline (mean follow-up: 33 wks) were comparable across treatment arms (Table). No significant differences in median time to first deterioration (wks) were seen with LEN18 vs LEN24 across instruments (EQ5D-VAS, 21.9 vs 16.3, HR 0.92 [95% CI 0.61–1.39]; EQ5D-HUI, 28.1 vs 16.0, HR 0.66 [95% CI 0.43–1.02]; FACT-G 7 points MID, 24.0 vs 16.1, HR 0.80 [95% CI 0.53–1.22]). Similar results were seen for median time to definitive deterioration (wks) (EQ5D-VAS, 72.1 vs 88.7, HR 1.58 [95% CI 0.92–2.70]; EQ5D-HUI, 73.9 vs 71.4, HR 0.89 [95% CI 0.53–1.49]; FACT-G 7 points MID, 72.4 vs 88.1, HR 0.78 [95% CI 0.46–1.30]).
CONCLUSIONS: In RR-DTC, HRQoL for pts in the LEN18 arm was not statistically different from pts in the LEN24 arm. These data combined with prior efficacy data support use of the LEN24 starting dose in pts with RR-DTC.
