Poster Presentation Joint 2016 COSA and ANZBCTG Annual Scientific Meeting

Phase 2 Study of Lenvatinib in Patients With Differentiated, Medullary, and Anaplastic Thyroid Cancer: Final Analysis Results (#263)

Shunji Takahashi 1 , Naomi Kiyota 2 , Tomoko Yamazaki 3 , Naoko Chayahara 2 , K. Nakano 1 , Lina Inagaki 1 , Kazuhisa Toda 4 , Tomohiro Enokida 3 , Hironobu Minami 2 , Yoshinori Imamura 2 , Tatsuya Sasaki 5 , Takuya Suzuki 5 , Katsuki Fujino 5 , Corina Dutcus 6 , Louise Young 7 , Makoto Tahara 3
  1. Department of Medical Oncology, Chemotherapy Center and Cancer Institute Hospital Japanese Foundation for Cancer Research, Tokyo, Japan
  2. Department of Medical Oncology and Hematology, Kobe University Hospital, Kobe, Japan
  3. Department of Head and Neck Medical Oncology, National Cancer Center Hospital East, Kashiwa, Japan
  4. Department of Head and Neck Oncology, Cancer Institute Hospital Japanese Foundation for Cancer Research, Tokyo, Japan
  5. Eisai Co., Ltd, Tokyo, Japan
  6. Eisai Inc., Woodcliff Lake, New Jersey, United States of America
  7. Eisai Australia Pty Ltd, Melbourne, VIC, Australia

Aim

Thyroid cancer is classified into differentiated (DTC), medullary (MTC), and anaplastic (ATC) types. Lenvatinib prolonged progression-free survival (PFS) versus placebo in the phase 3 SELECT trial for 131I-refractory DTC (RR-DTC). Initial results of this phase 2 trial in RR-DTC, MTC, and ATC were previously reported; final results are reported here.

Methods

This single-arm, open-label study was conducted in Japan (updated data cutoff: 9 July 2015). Patients received lenvatinib (24 mg/d, 28-d cycles) until progressive disease or development of unacceptable toxicity. Primary endpoint was safety; secondary endpoints included PFS, overall survival (OS), overall response rate (ORR), and disease control rate (DCR).

Results

Fifty-one patients (25 with RR-DTC [previously 23], 9 with MTC, and 17 with ATC [previously 11]) enrolled. All had ≥1 treatment-emergent adverse event (TEAE). Common TEAEs included hypertension (90%), decreased appetite (78%), palmar-plantar erythrodysesthesia syndrome (77%), fatigue (73%), proteinuria (61%), stomatitis (57%), and diarrhea (55%). Incidences of grade 3/4 TEAEs were similar among subgroups (RR-DTC, 72%; MTC, 100%; ATC, 88%). Only 1 patient discontinued due to a TEAE. There were 4 fatal AEs (none treatment-related). Most patients showed tumor shrinkage. Median duration of treatment was 5.5 months (range, 0.7–33.1) for patients with ATC; 8 received lenvatinib for >6 months. Median PFS (95% CI) was 25.8 (18.4–not evaluable [NE]), 9.2 (1.8–NE) and 7.4 (1.7–12.9) months for RR-DTC, MTC, and ATC, respectively. Median OS (95% CI) was 31.8 (31.8–NE), 12.1 (3.8–NE), and 10.6 (3.8–19.8) months for RR-DTC, MTC, and ATC, respectively. ORR was 68% for RR-DTC, 22% for MTC and 24% for ATC (all partial responses). DCR was 100% for RR-DTC and MTC and 71% for ATC.

Conclusions

Lenvatinib showed tumor shrinkage in most patients, including those with ATC. Toxicities were manageable with dose modifications. Lenvatinib efficacy, especially in ATC, warrants further investigation.