Bayer extends elinzanetant trials to include breast cancer

Bayer has added another clinical trial to its extensive phase 3 programme for oral neurokinin antagonist elinzanetant, hoping to show that it can treat vasomotor symptoms (VMS) in breast cancer patients.

Elinzanetant is already being tested in the OASIS trials for VMS associated with menopause – an indication in which Bayer is in a head-to-head race with Astellas and its fezolinetant drug candidate – and breast cancer could represent a sizeable additional patient population for the drug.

Bayer's new study is OASIS 4, which will be carried out in breast cancer patients and women with high risk of breast cancer with vasomotor symptoms caused by endocrine therapy.

It will enrol around 400 patients at about 95 centres in 15 countries and will look at a 120 mg once daily dose of elinzanetant, the same as is being tested in Bayer's menopausal VMS studies, which are due to read out later this year or in early 2023.

While a smaller patient group than menopausal women, carving out a niche in breast cancer could give Bayer an advantage over Astellas, which is currently in the lead with fezolinetant as it is due to hear from the FDA on a filing for the drug in menopausal VMS next February.

There are around 2.3 million new cases of breast cancer diagnosed globally every year, and 70% of them are so-called hormone receptor-positive – meaning they can be treated with endocrine therapies that put them at risk of VMS.

There is an acute medical need for an effective non-hormonal treatment for VMS caused by endocrine therapy in breast cancer patients and women at high risk for developing breast cancer as at the moment no treatment options are available, according to Bayer.

"For women treated with endocrine therapy for breast cancer – potentially for numerous years – vasomotor symptoms can intensively affect their quality of life and treatment continuation, which in turn might impact the effectiveness of their cancer therapy and hence their survival," said Dr Christian Rommel, Bayer's R&D chief.

"By adding OASIS 4 to our phase 3 programme with elinzanetant, we aim to help patients experiencing vasomotor symptoms caused by their endocrine therapy, to increase their quality of life," he added.

There is an acute medical need for an effective non-hormonal treatment for VMS caused by endocrine therapy in breast cancer patients and women at high risk for developing breast cancer as, at the moment, no treatment options are available.

Bayer acquired elinzanetant as part of its takeover of UK biotech KaNDy Therapeutics in 2020, while Astellas acquired fezolinetant as part of its 2017 takeover of Ogeda.