Treatment of symptomatic uterine adenomyosis with linzagolix, an oral gonadotrophin-releasing hormone antagonist: a pilot study.

RESEARCH QUESTION: Does a once-daily regimen of linzagolix, a new oral gonadotrophin-releasing hormone (GnRH) antagonist, given at a fully suppressive dose (200 mg) for 12 weeks, followed by a partially suppressive dose (100 mg) for a further 12 weeks, reduce adenomyotic uterine size and associated symptoms? DESIGN: Eight women (aged 37-45 years) with adenomyosis confirmed by magnetic resonance imaging (MRI) were enrolled in a single-centre, open-label pilot study. The primary efficacy end-point was the change in uterine volume on MRI at 24 weeks. Secondary efficacy end-points included serum oestradiol, overall pelvic pain, dysmenorrhoea, non-menstrual pelvic pain, dyspareunia, dyschezia and quality of life (QoL). Bone mineral density (BMD) was assessed at baseline and 24 weeks. RESULTS: At baseline, uterine volume (mean ± SD) was 333 ± 250 cm3. After 24 weeks, it was 204 ± 126 cm3, a reduction of 32% from baseline (P = 0.0057). After 12 weeks, it was 159 ± 95 cm3, a reduction of 55% (P < 0.0001). Median serum oestradiol was suppressed below 20 pg/ml during the 12 weeks on 200 mg linzagolix, and maintained below 60 pg/ml on 100 mg linzagolix. Improvements in overall pelvic pain, dysmenorrhoea, non-menstrual pelvic pain, dyspareunia, dyschezia and QoL were observed. Mean percentage change in BMD loss at 24 weeks was -2.4%, -1.3% and -4.1% for the spine, femoral neck and total hip, respectively. The most common adverse events were hot flushes. CONCLUSIONS: A once-daily regimen of 200 mg linzagolix for 12 weeks and then 100 mg for another 12 weeks decreased adenomyotic uterine volume and improved associated symptoms.

Uterine Adenomyosis Treated by Linzagolix, an Oral Gonadotropin-Releasing Hormone Receptor Antagonist: A Pilot Study with a New 'Hit Hard First and then Maintain' Regimen of Administration.

(1) Background: The aim of the present pilot study was to study the effect of a new oral gonadotropin-releasing hormone antagonist on adenomyosis. (2) Methods: Eight premenopausal women, aged between 37 and 45 years, presenting with heavy menstrual bleeding, pelvic pain, and dysmenorrhea due to diffuse and disseminated uterine adenomyosis, confirmed by magnetic resonance imaging (MRI), received 200 mg linzagolix once daily for a period of 12 weeks, after which they were switched to 100 mg linzagolix once daily for another 12 weeks. The primary efficacy endpoint was the change in volume of the adenomyotic uterus from baseline to 24 weeks, evaluated by MRI. Secondary efficacy endpoints included the change in uterine volume from baseline to 12 and 36 weeks by MRI, and also weeks 12, 24, and 36 assessed by transvaginal ultrasound (TVUS). Other endpoints were overall pelvic pain, dysmenorrhea, non-menstrual pelvic pain, dyspareunia, amenorrhea, quality of life measures, bone mineral density (BMD), junctional zone thickness, and serum estradiol values. (3) Results: Median serum estradiol was suppressed below 20 pg/mL during the 12 weeks on linzagolix 200 mg, and maintained below 60 pg/mL during the second 12 weeks on linzagolix 100 mg. At baseline, the mean ± SD uterine volume was 333 ± 250 cm3. After 24 weeks of treatment, it was 204 ± 126 cm3, a reduction of 32% (p = 0.0057). After 12 weeks, the mean uterine volume was 159 ± 95 cm3, a reduction of 55% from baseline (p = 0.0001). A similar pattern was observed when uterine volume was assessed by TVUS. Improvements in overall pelvic pain, dysmenorrhea, non-menstrual pelvic pain, dyspareunia, and dyschezia, as well as quality of life measured using the EHP-30 were also observed. Mean percentage BMD loss at 24 weeks was, respectively, -2.4%, -1.3%, and -4.1% for the spine, femoral neck, and total hip. The most common adverse events were hot flushes, which occurred in 6/8 women during the first 12 weeks, and 1/8 women between 12 and 24 weeks. (4) Conclusions: Linzagolix at a dose of 200 mg/day reduced uterine volume, and improved clinically relevant symptoms. Treatment with 100 mg thereafter retains the therapeutic benefits of the starting dose while minimizing side effects. This 'hit hard first and then maintain' approach may be the optimal way to treat women with symptomatic adenomyosis.

Characterization of the metal ion binding properties of the hepatitis C virus RNA polymerase.

The hepatitis C virus nonstructural 5B protein (NS5B) protein has been shown to require either magnesium or manganese for its RNA-dependent RNA polymerase activity. As a first step toward elucidating the nature and the role(s) of the metal ions in the reaction chemistry, we have utilized endogenous tryptophan fluorescence to quantitate the interactions of magnesium and manganese ions with this protein. The association of either Mg(2+) or Mn(2+) ions with the enzyme resulted in a decrease in the intensity of the tryptophan emission spectrum. This decrease was used to determine the apparent dissociation constants for both ions. The apparent K(d) values for the binding of Mg(2+) and Mn(2+) ions to the free enzyme were 3.1 and 0.3 mm, respectively. Dual ligand titration experiments demonstrated that both ions bind to a single common site, for which they compete. The kinetics of real time metal ion binding to the NS5B protein were also investigated. Based on the results of our fluorescence and near-UV circular dichroism experiments, we show that NS5B undergoes conformational changes upon the binding of metal ions. However, this process does not significantly stimulate the binding to the RNA or NTP substrates. We envisage that the ion-induced conformational change is a prerequisite for catalytic activity by both correctly positioning the side chains of the residues located in the active site of the enzyme and also contributing to the stabilization of the intermediate transition state.