Poster Presentation 2025 Joint Meeting of the COSA ASM and IPOS Congress

The efficacy of lemborexant for insomnia comorbid with breast cancer: a prospective observational study (WJOG14921B, LUNAR study) (126125)

Yukinori Ozaki 1 , Mari Hosonaga 1 , Hiroko Masuda 2 , Rurina Watanuki 3 , Kenjiro Aogi 4 , Sasagu Kurozumi 5 , Hidenori Kamio 6 , Manabu Futamura 7 , Tsutomu Iwasa 8 , Kaori Terata 9 , Yoshinori Saeki 10 , Shigehisa Kitano 11 , Kentaro Sakamaki 12 , Kiyomi Nonogaki 1 , Shun Osaka 13 , Fiona Gardiner 14 , Toshimi Takano 1
  1. Department of Breast Medical Oncology, The Cancer Institute Hospital of JFCR, Koto-ku, Japan
  2. Department of Breast Surgery, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital, Bunkyo-ku, Japan
  3. Department of Breast Surgery, National Cancer Center Hospital East, Chiba, Japan
  4. Department of Breast Surgery, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan
  5. Department of Breast Surgery, IUHW Narita Hospital, Narita, Japan
  6. Department of Breast Surgery, Tokyo Metropolitan Cancer and Infectious Disease Center, Komagome Hospital, Tokyo, Japan
  7. Department of Breast Surgery, Gifu University Hospital, Gifu, Japan
  8. Medical Oncology, Kindai University Faculty of Medicine, Osaka, Japan
  9. Breast and Endocrine Surgery, Akita University Hospital, Akita, Japan
  10. Department of Psychooncology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
  11. Department of Advanced Medical Development, The Cancer Institute Hospital of JFCR, Koto-ku, Japan
  12. Faculty of Health Data Science, Juntendo University, Tokyo, Japan
  13. Medical HQs, Eisai Co., Ltd.,, Tokyo, Japan
  14. Eisai Australia Pty Ltd, Melbourne, Victoria, Australia

Objectives/purpose

Patients with breast cancer undergoing endocrine therapy have the highest frequency of insomnia among all cancers. Lemborexant (LEM), a dual-orexin-receptor-antagonist, is approved for the treatment of adults with insomnia. Although LEM has been used in clinical practice for patients with insomnia, including cancer patients, no prospective study has evaluated LEM in patients with breast cancer and insomnia.

 

Sample and setting

This multicentre, prospective, observational study evaluated the efficacy of LEM in patients with breast cancer and insomnia. Two cohorts were evaluated: early breast cancer cohort (eBC) and advanced/metastatic breast cancer cohort (mBC). Enrolled patients met DSM-5 criteria for insomnia disorder, had a baseline Insomnia Severity Index (ISI) score ≥10 points and were receiving or scheduled to receive endocrine therapy.

 

Procedures

LEM starting dose was 5mg and could be titrated up (10mg) and down based on clinical practice. The follow-up period was 3 months. The primary endpoint was mean change in ISI score from baseline to 1 month in eBC (predefined ISI threshold was −6.0 points). Secondary endpoints included changes in Cancer Fatigue Scale, EORTC QLQ C30 and Patient Health Questionnaire-9.

 

Results

From September 2022–July 2024, 59 subjects were enrolled (eBC: n=49; mBC: n=10). In eBC, the median age was 49 years (range, 34–78). Baseline mean ISI total score was 14.35. Mean change in ISI score from baseline to 1 month was −5.08 (P=0.937), showing modest improvement that did not reach the predefined threshold. One case of grade 3 liver dysfunction was reported. All other AEs were mild to moderate and consistent with previous reports. Subgroup analysis by patient background and QoL data will be presented.

 

Conclusion and clinical implications

This is the first prospective study to evaluate the efficacy of LEM for insomnia comorbid with breast cancer. LEM showed modest improvement in ISI score at 1 month.