Drug eases vasomotor symptoms from endocrine therapy for breast cancer, study finds
A placebo-controlled manufacturer's trial found that women taking endocrine therapy for breast cancer had significantly fewer vasomotor symptoms with elinzanetant, an investigational drug, at four and 12 weeks.
Elinzanetant, an investigational drug, reduced vasomotor symptoms in women receiving endocrine therapy for hormone receptor-positive breast cancer, according to an industry-conducted study.
In a phase 3 trial, women ages 18 to 70 years with moderate to severe vasomotor symptoms associated with endocrine therapy (defined as tamoxifen or aromatase inhibitors with or without GnRH analogues) for hormone receptor-positive breast cancer were randomly assigned in a 2:1 ratio to receive once-daily elinzanetant, 120 mg for 52 weeks, or once-daily placebo for 12 weeks followed by once-daily elinzanetant, 120 mg for 40 weeks. The primary end points were change in the mean daily frequency of moderate to severe vasomotor symptoms at week 4 and week 12. Bayer funded and conducted the trial, and most of the authors were Bayer employees. The results were published June 2 by the New England Journal of Medicine.
Overall, 316 women were assigned to the elinzanetant group (88.0% White; mean age, 50.8 years) and 158 were assigned to the placebo group (88.6% White; mean age, 51.5 years). Their mean daily frequency of moderate to severe vasomotor symptoms at baseline was 11.4 episodes (95% CI, 10.7 to 12.2) and 11.5 episodes (95% CI, 10.5 to 12.5), respectively. At week 4, the mean change from baseline in mean daily frequency of moderate to severe vasomotor symptoms was −6.5 episodes (95% CI, −7.2 to −5.8) in the elinzanetant group and −3.0 episodes (95% CI, −3.9 to −2.2) in those getting placebo (least-squares mean difference, −3.5 episodes [95% CI, −4.4 to −2.6]; P<0.001). At week 12, the mean change was −7.8 episodes (95% CI, −8.5 to −7.1) and −4.2 episodes (95% CI, −5.2 to −3.2), respectively (least-squares mean difference, −3.4 episodes [95% CI, −4.2 to −2.5]; P<0.001).
On secondary end points, women in the elinzanetant group had a greater mean change in sleep disturbance score from baseline to week 12 versus those in the group receiving placebo (−10.6 points vs. −4.1 points; least-squares mean difference, −6.1 points [95% CI, −7.5 to −4.8 points]; P<0.001), along with a greater mean change in score on an overall measure of quality of life related to menopausal symptoms (−1.3 points vs. −0.5 point; least-squares mean difference, −0.7 point [95% CI, −0.9 to −0.5 point]; P<0.001). In weeks 1 through 12, 69.8% of the elinzanetant group and 62.0% of the placebo group reported at least one adverse event, most commonly headache, fatigue, and somnolence. There were serious adverse events in weeks 1 through 12 in 2.5% of those receiving elinzanetant and 0.6% of those receiving placebo.
Most of the study participants were White, only one participant was taking endocrine therapy to prevent breast cancer, and the patient-reported outcomes were subjective, among other limitations, the authors noted. They concluded that treatment with elinzanetant resulted in significant decreases in the frequency of vasomotor symptoms and sleep disturbances and improvements in health-related quality of life in women with moderate-to-severe vasomotor symptoms taking endocrine therapy for breast cancer.
An accompanying editorial agreed that the results of the trial are promising and inform the potential role of elinzanetant in easing vasomotor symptoms in women who have or have had breast cancer, noting that postmenopausal hormone therapy for vasomotor symptoms is largely contraindicated in this population.
“Future research evaluating potential interactions between age, menopausal status, or type of endocrine therapy and the efficacy of elinzanetant might help inform which patients are more likely to benefit from treatment,” the editorialist wrote. “Meanwhile, the present trial supports elinzanetant as a promising new treatment for persons with breast cancer with bothersome vasomotor symptoms while receiving endocrine therapy.”