Impact of bodyweight (BW)-based starting doses on safety and efficacy of lenvatinib (LEN) in patients (pts) with hepatocellular carcinoma (HCC).

e16119 Background: In Study 202, pts received LEN 12 mg/d for treatment of unresectable (u)HCC, irrespective of BW. Correlations between early dose adjustments and BW in Study 202 led to BW-adjusted dosing in the phase 3 REFLECT study of LEN in uHCC. In REFLECT, pts <60 kg received LEN 8 mg/d and pts ≥60 kg received LEN 12 mg/d. While improvements in safety were expected by reducing the LEN starting dose to 8 mg/d in pts <60 kg, any differences in safety and efficacy of BW-adjusted dosing vs standard dosing among pts with lower BW have yet to be determined. Herein, we compare safety and efficacy of LEN based on pts’ BW (<60 kg vs ≥60 kg) in Study 202 (LEN 12 mg/d irrespective of BW) and in Japanese pts in REFLECT (dose adjusted by BW). Methods: This ad hoc analysis included all pts from Study 202 (n=46; all Asian, 43 Japanese) and Japanese pts from REFLECT (n=81). Safety and efficacy were assessed in Study 202 and REFLECT according to pt BW (<60 kg vs ≥60 kg). Tumors were assessed using mRECIST, by independent radiologic review. Results: In Study 202, pts in the <60 kg group had a median treatment duration of 5.8 mos and received 57% of the LEN planned starting dose (PSD); pts in the ≥60 kg group had a median treatment duration of 9.4 mos and received 78.6% of the LEN PSD. Among Japanese pts in REFLECT, median treatment duration was 5.7 mos in both treatment groups; pts in the LEN 8 mg group received 79.1% of the PSD and pts in the LEN 12 mg group received 70.7% of the PSD. In Study 202, treatment-related adverse events (TRAEs) led to dose reduction in 80.8% of pts in the <60 kg group and 55% of pts in the ≥60 kg group. In REFLECT, TRAEs led to dose reductions in 52.5% of pts in the LEN 8 mg group and 70.7% of pts in the LEN 12 mg group. Serious TRAEs occurred at incidences of 46.2% and 10.0% in Study 202 in the <60 kg and ≥60 kg groups, and 15.0% and 22.0% in REFLECT in the LEN 8 mg and LEN 12 mg groups, respectively. Efficacy results are in the Table. Conclusions: Despite the small sample size, this comparison of Study 202 pts and Japanese pts from REFLECT indicates that BW-adjusted LEN dosing in pts with uHCC yielded comparable efficacy between pts <60 kg who received LEN 8 mg and pts ≥60 kg who received LEN 12 mg. The safety profile was favorable in pts <60 kg who received LEN 8 mg in REFLECT vs those who received LEN 12 mg in Study 202. Fewer serious TRAEs and dose reductions due to TRAEs were observed in pts with lower BW who received the LEN 8 mg starting dose in REFLECT. These data suggest that by reducing the starting dose from LEN 12 mg to 8 mg in pts with uHCC and lower BW (<60 kg), safety is improved without compromising efficacy. Clinical trial information: NCT00946153; NCT01761266. [Table: see text]