Bayer's Elinzanetant Shows Promise in Reducing Hot Flashes for Breast Cancer Patients

Bayer's elinzanetant has demonstrated positive results in a Phase III trial, offering a potential non-hormonal treatment for vasomotor symptoms (VMS) in women undergoing endocrine therapy for breast cancer or at high risk of developing the disease. The OASIS 4 study met its primary endpoints, showing statistically significant reductions in the frequency of moderate to severe hot flashes compared to placebo.

The double-blind, randomized, placebo-controlled multicenter study, involved 474 patients across 16 countries (excluding the US). Participants received either a 120 mg oral dose of elinzanetant or a placebo. The study evaluated the efficacy and safety of elinzanetant over 52 weeks, with an optional extension of up to 2 years.

Key Findings from OASIS 4

The OASIS 4 trial achieved all primary and secondary endpoints. Key results included:

• Reduction in VMS Frequency: Significant reductions in the frequency of moderate to severe VMS from baseline to weeks 4 and 12 compared to placebo.
• Reduction in VMS Severity: Decreased severity of VMS at weeks 4 and 12.
• Improved Sleep and Quality of Life: Improvements in sleep disturbances and menopause-related quality of life at week 12.
• Rapid Onset: Reduction in VMS frequency observed as early as week 1, sustained over the 52-week study period.

The safety profile of elinzanetant was consistent with previous studies in postmenopausal women with VMS.

The Need for Non-Hormonal Options

Up to 80% of women experience VMS during menopause, with one-third reporting severe symptoms that can last for a decade or more. For women undergoing adjuvant endocrine therapy for hormone receptor-positive breast cancer, VMS is a common side effect that can significantly impact quality of life and treatment adherence. Currently, there are limited approved non-hormonal treatment options available for this patient population.

Dr. Fatima Cardoso, principal investigator of OASIS 4, noted, "For women undergoing endocrine therapy against breast cancer, menopausal symptoms like VMS and sleep disturbances are very common and can significantly affect quality of life, potentially impacting treatment adherence. The positive results from OASIS 4 bring us one step closer to a much-needed non-hormonal option for managing VMS in breast cancer patients and women at risk of breast cancer."

Elinzanetant's Mechanism of Action

Elinzanetant is a dual neurokinin-1 and 3 (NK-1,3) receptor antagonist. It works by modulating the activity of KNDy neurons in the hypothalamus, which become hyperactive due to reduced estrogen levels during menopause or endocrine therapy. This hyperactivation disrupts thermoregulation, leading to VMS.

Regulatory Status and Future Plans

Bayer has submitted marketing authorization applications for elinzanetant in the US, EU, and other global markets. The FDA has accepted the New Drug Application (NDA) for elinzanetant, with a target action date of July 26, 2025. If approved, elinzanetant would compete with Astellas' Veozah (fezolinetant), another NK3 receptor antagonist already on the market.

Dr. Christian Rommel, Head of Research and Development at Bayer's Pharmaceuticals Division, stated, "Elinzanetant has consistently demonstrated positive results across all four phase 3 clinical trials... Importantly, OASIS 4 is the first pivotal international study to assess the safety and efficacy of a non-hormonal treatment approach for women with or at high risk of breast cancer who are suffering from VMS caused by adjuvant endocrine therapy."

Detailed results from the OASIS 4 trial will be presented at upcoming scientific congresses.