Linzagolix Is Safe and Effective for Heavy Menstrual Bleeding Due to Uterine Fibroids

Ernest Loumaye, MD, PhD

Linzagolix can be beneficial for the treatment of heavy menstrual bleeding due to uterine fibroids, according to new findings from a phase 3 trial.

Ernest Loumaye, MD, PhD, ObsEva co-founder and chief executive officer, and his team of investigators have shared results from the PRIMROSE 2 trial, which evaluated the efficacy and safety of once-daily oral linzagolix on 535 women with heavy menstrual bleeding due to uterine fibroids. The trial included 100 mg and 200 mg doses with and without hormonal add-back therapy.

The drug has the potential to relieve symptoms for the millions of women suffering from heavy menstrual bleeding due to uterine fibroids.

Patients included in the trial were considered responders if they had a menstrual blood loss volume of <80 mL and >50% reduction from baselines in menstrual blood loss volume at 24 weeks.

There was a 93.9% responder rate for 200 mg with add-back therapy (P <.001) and a 56.7% responder rate for 100 mg without add-back therapy (P <.001).

Over 50% of women responded to the 100 mg dose without add-back therapy, which “provides a meaningful option for the significant proportion of women who cannot or do not want to take exogenous hormones,” Loumaye said in a statement.

The placebo group had a responder rate of 29.4%.

Both of the doses achieved clinically relevant rates of amenorrhea (P <.001), reduction in pain (P <.001), and improvement in quality of life (P <.001). Patients also experienced a significant improvement (P <.001) in hemoglobin levels, a reduction in number of days bleeding, and a reduction in uterine volume.

Investigators noted that there was a significant reduction in fibroid volume for the 200 mg dose with add-back therapy (P <.008).

Loumaye and his colleagues noted that while the safety profile was aligned with initial expectations and that linzagolix was well-tolerated, there were still some adverse events. The most frequent adverse events, which occurred in more than 5% of patients, were headache, hot flushes, and anemia.

Multiple dosing options would address a need for a diverse population of women with uterine fibroids who need non-surgical alternatives for heavy menstrual bleeding.

Linzagolix is a full suppression option, a potentially unique partial suppression option, and only needs to be taken once a day without food, Loumaye said in a conference call to investors on Monday.

ObsEva now expects to have the primary endpoints for its PRIMROSE 1 trial in Q2 2020, 12-month results for PRIMROSE 2 in mid-2020, and marketing authorization and new drug regulatory submissions are anticipated in Q4 2020, and Q1 2021.