Bayer lifts lid on pivotal data ahead of filings to challenge Astellas for menopause market

Bayer’s master plan for its OASIS program is coming together, with the German drugmaker posting phase 3 data that suggest it could challenge Astellas for a recently unlocked menopause market. 

The phase 3 data come from the OASIS 1 and 2 studies. Bayer reported the success of the trials in January, and followed up with news of a hit on a third study in March, but kept the data to itself. With Astellas’ Veozah authorized in the treatment of hot flashes associated with menopause, the details will matter if Bayer wins approval for elinzanetant and starts trying to claim a piece of the market. 

Bayer used the 2024 American College of Obstetricians and Gynecologists annual meeting to reveal the data behind the hits on the co-primary endpoints. Both studies looked at the effect of elinzanetant on the severity and frequency of hot flashes after four weeks and 12 weeks of oral daily doses. 

In OASIS 1, Bayer reported mean reductions versus placebo in the frequency of hot flashes of 3.29 at Week 4 and 3.22 at Week 12. The Week 4 and Week 12 reductions in frequency in OASIS 2 were 3.04 and 3.24, respectively.

Astellas won approval on the strength of phase 3 trials that linked Veozah to placebo-adjusted reductions (PDF) in hot flash frequency of 2.1 and 2.6 at week 4 and 2.6 and 2.5 at week 12. Comparing data across different clinical trials can give misleading impressions but the available evidence suggests Bayer could be competitive.

Across OASIS 1 and 2, Bayer reported mean reductions versus placebo for severity of 0.33 and 0.22 at Week 4 and 0.40 and 0.28 at Week 12. Astellas reported placebo-adjusted reductions in severity of 0.2 and 0.3 at both Week 4 and Week 12.  

Sleep is an area in which elinzanetant may have an edge over Astellas’ neurokinin-3 (NK-3) antagonist Veozah. Elinzanetant acts on both NK-3 and NK-1, a related receptor that research suggests may have effects on insomnia and mood unrelated to menopause. Bayer reported statistically significant improvements in sleep disturbances and menopause-related quality of life. Astellas has also posted positive sleep data.

With three phase 3 successes under its belt, Bayer is preparing to file for approval of elinzanetant. Bayer CEO Bill Anderson said “preparations to obtain first market authorizations are running at full steam” on an earnings call this week. The molecule, which Bayer acquired in its KaNDy Therapeutics buyout, is part of a thin late-phase pipeline that needs to offset anticipated generic erosion of Eylea and Xarelto sales.