Myovant Reports Phase 3 Data of Relugolix in Uterine Fibroids

May 14, 2019

Impact Level: Moderate

• The LIBERTY 1 study met its primary efficacy endpoint with 73.4% of women receiving once daily oral relugolix combination therapy achieving the responder criteria compared with 18.9% of women receiving placebo (p < 0.0001). Response was defined as a menstrual blood loss volume of less than 80 mL and a 50 percent or greater reduction from baseline in menstrual blood loss volume during the last 35 days of the 24-week treatment period.

• Six key secondary endpoints were achieved, including an 84.3% reduction in menstrual blood loss from baseline (p=< 0.0001), reduction in pain (p=< 0.0001), and improvement in quality of life (p=< 0.0001).
• Safety and tolerability was acceptable. Bone mineral density maintained at levels comparable to placebo.  The overall incidence of AEs was similar in the treatment and placebo groups. In the treatment group, 5% of women discontinued treatment early due to adverse events compared with 4% in the placebo group. Hot flush was the most frequent AE in the treatment group compared to placebo (10% vs 8%)
• The company is waiting for the replicate LIBERTY 2 study results (expected in Q3) before finding out if regulators will allow an expedited review. An NDA filing is expected in 4Q 2019.
• The company indicated in the Q&A that it is considering including a single pill that includes add back therapy with the filing. This would differentiate them from Abbvie’s Orlissa, which is currently approved to treat endometriosis pain and is in phase 3 study in uterine fibroids.

inThought Analysis

Myovant released the LIBERTY 1 data in line with timing expectations but LIBERTY 2 data has been pushed out from 2Q expectation to 3Q. However, the launch timing expectation remains 4Q 2020.

The data looked positive for relugolix as the primary and most secondary endpoints were met, but the data did not stand out from the data presented on AbbVie’s Orlissa at ACOG 2019. Menstrual blood loss (MLB) looked similar with both of these drugs. Relugolix did report on a secondary endpoint of percent change in uterine fibroid volume but this did not meet statistical significance (p=0.09). This may provide earlier competitor, ObsEva’s linzagolix, the opportunity to stand out.  We may see data on linzagolix as soon as Q4 2019. Notably, Orlissa did not release data on changes in uterine fibroid volume.

Overall, these new, oral GnRH antagonists are much easier to use than Lupron.  You don’t get the flare effect, they have a rapid onset of action and data from ACOG indicated that you don’t have to have add-back therapy as you don’t have to lower estrogen levels to zero.

Source: Myovant press release and conference call, May 14 2019