Bayer's Phase III Study Yields Positive Breast Cancer Results

Elinzanetant successfully met the primary endpoints of the study demonstrating statistically significant reductions in the frequency of moderate to severe vasomotor symptoms (VMS, also known as hot flashes) from baseline to week 4 and 12 compared to placebo. The study also achieved all secondary endpoints demonstrating reductions in severity of VMS at week 4 and 12, VMS frequency reduction at week 1 as well as maintaining the effects over the study period. Elinzanetant also showed improvements of sleep disturbances and menopause-related quality of life at week 12 compared to placebo. The safety profile over 52 weeks observed in the OASIS 4 study is generally consistent with previously conducted studies and published data on elinzanetant in postmenopausal women with VMS.

“Elinzanetant has consistently demonstrated positive results across all four Phase III clinical trials that assessed the efficacy and safety for the treatment moderate to severe vasomotor symptoms associated with menopause or caused by adjuvant endocrine therapy,” said Dr. Christian Rommel, Head of Research and Development and Member of the Executive Committee of Bayer’s Pharmaceuticals Division. “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, reaffirming our commitment at Bayer to advancing innovative treatments for the different needs of women and their health.”

Breast cancer is the most frequent cancer in women globally with 2.3 million new cases in 2020, with nearly 70% of tumors being hormone-receptor positive. Adjuvant endocrine therapy is well established in guidelines worldwide and routinely prescribed to all women with hormone-positive breast cancer. Treatment with adjuvant endocrine therapy (such as tamoxifen or aromatase inhibitors) for up to 10 years substantially reduces the breast cancer mortality rate throughout the 2 decades after diagnosis. Adjuvant endocrine therapy can also be used as primary prevention, in women at high risk of developing breast cancer. VMS (also referred to as hot flashes) is a common adverse reaction of the adjuvant endocrine therapy, which may affect quality of life and treatment compliance, with potential impact on recurrence and long term outcomes. There is unmet medical need for an effective non-hormonal treatment for VMS caused by adjuvant endocrine therapy as currently no approved treatment options are available.

“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,” said Dr. Fatima Cardoso, Principal Investigator of OASIS 4, from Lisbon, Portugal. “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 is the first dual neurokinin-1 and 3 (NK-1,3) receptor antagonist, in late-stage clinical development for the non-hormonal treatment of moderate to severe VMS associated with menopause or caused by adjuvant endocrine therapy for breast cancer, administered orally once daily. OASIS 4 (NCT05030584) is the first pivotal international Phase III study to assess the safety and efficacy of a non-hormonal treatment of moderate to severe VMS caused by adjuvant endocrine therapy. It is the fourth Phase III study in the OASIS clinical development program with positive topline results, with details planned to be presented at upcoming scientific congresses. Data from OASIS 1 and 2 were published in the Journal of the American Medical Association (JAMA) in August 2024. Detailed results of the Phase III study OASIS 3 providing additional efficacy and safety data over 52 weeks were presented at The Menopause Society (TMS) annual meeting in September 2024. Based on the positive results from the Phase III clinical development program, submissions for marketing authorizations for elinzanetant are ongoing in the US, EU and other markets around the world.

About the Elinzanetant clinical development program
The Phase III clinical development program of elinzanetant, OASIS, currently comprises four Phase III studies: OASIS 1, 2, 3 and 4. OASIS 1 and 2 investigated the efficacy and safety of elinzanetant administered orally once daily in women with moderate to severe VMS associated with menopause over 26 weeks and randomized 396 and 400 postmenopausal women between 40 and 65 years across 184 sites in 15 countries. Patients in the elinzanetant arm received a 120 mg dose of elinzanetant once daily for 26 weeks and patients in the control arm received a matching placebo once daily for 12 weeks, followed by elinzanetant 120 mg dose for 14 weeks. OASIS 3 investigated the efficacy and safety of elinzanetant for the treatment of vasomotor symptoms associated with menopause over 52 weeks and randomized 628 postmenopausal women between 40 and 65 years across 83 sites in 9 countries. OASIS 4 is a double-blind, randomized, placebo-controlled multicenter study to investigate efficacy and safety of elinzanetant for the treatment of vasomotor symptoms caused by adjuvant endocrine therapy, over 52 weeks and optionally for an additional 2 years in women with, or at high risk for developing hormone-receptor positive breast cancer. 474 patients at 90 centers in 16 countries (excluding the US) were randomized.