Drug safety evaluation of ulipristal acetate in the treatment of uterine fibroids

Experimental and new investigational drugs for the treatment of uterine fibroids

INTRODUCTION

Uterine fibroids, the most prevalent benign tumors among reproductive-age women, pose treatment challenges that range from surgical interventions to medical therapies for symptom control. Progestins and estroprogestins effectively manage uterine bleeding by suppressing dysfunctional endometrium over fibroids. While GnRH agonists represent a crucial milestone in symptom treatment, their prolonged use results in menopausal-like symptoms and irreversible bone mineral density loss. Advancements in understanding fibroid pathophysiology have prompted the exploration of new compounds to overcome current therapy limitations.

AREAS COVERED

This manuscript offers an updated overview of investigational drugs for symptomatic uterine fibroids.

EXPERT OPINION

Despite ulipristal acetate's well-established efficacy as a selective progesterone receptor modulator (SPRM) in fibroid treatment, its prescription has declined due to the rare but severe risk of liver damage. Oral GnRH antagonists, like elagolix, relugolix, and linzagolix, with their novel pharmacodynamic properties, are gaining traction in fibroid management, inducing a dose-dependent reduction in circulating sex hormone levels. Ongoing research on natural compounds, such as vitamin D and epigallocatechin gallate (EGCG), presents emerging options for treating uterine fibroids. This evolving landscape reflects the ongoing efforts to improve therapeutic outcomes for individuals with symptomatic uterine fibroids.

Use of Ulipristal Acetate and Risk of Liver Disease: A Nationwide Cohort Study

CONTEXT

Large-scale clinical trials on the hepatotoxicity of ulipristal acetate (UPA) are lacking.

OBJECTIVE

This work aimed to determine the incidence of liver disease with UPA vs gonadotropin-releasing hormone (GnRH) agonists.

METHODS

A retrospective cohort study was conducted in South Korea of women with uterine fibroids from the Korean Health Insurance Data 2010 to 2018. Women with uterine fibroids were divided into 2 treatment groups: the UPA (5 mg/day) and GnRH agonist groups. Main outcome measures included the presence or absence of severe liver disease, mild liver disease, and liver transplantation.

RESULTS

Among the patients with uterine fibroids,17 207 patients were treated with GnRH agonists and 20 926 patients with UPA. After 1:1 propensity score matching for each group, there were 11 445 individuals. Neither group had a liver transplantation case. In the conditional logistic regression analysis, the incidence of total liver diseases (relative risk [RR] 1.111; 95% CI, 1.015-1.216) and mild liver diseases (RR 1.094; 95% CI, 1-1.196) was higher in the UPA group than in the GnRH agonist group, but that of severe liver diseases (RR 0.07; 95% CI, 0.001-4.412) and toxic liver disease (RR 1.256; 95% CI, 0.845-1.867) did not differ between the groups.

CONCLUSION

The incidence of severe liver disease, hepatic failure, and toxic liver disease was not different between the UPA and GnRH agonist groups. However, the incidence of mild liver disease was higher in the UPA group than in the GnRH agonist group. The incidence of hepatic damage with UPA was very low.

Vilaprisan, a New Selective Progesterone Receptor Modulator in Uterine Fibroid Pharmacotherapy-Will it Really be a Breakthrough?

BACKGROUND

Vilaprisan (VPR) is a new orally available selective progesterone receptor modulator (SPRM), with anti-proliferative activity against uterine fibroids (UFs). It definitively causes suppression of ovulation and inhibition of proliferation of endometrial, myometrial and UF cells.

PURPOSE

This review aims to summarize current knowledge on VPR from all studies, including clinical trials, conducted to date and to contextualize the potential role of VPR in future medical regimens for the treatment of UFs.

METHODS

We performed a literature search in PubMed US National Library of Medicine and Google Scholar databases. Both databases were extensively searched for all original and review articles/book chapters as well as congress abstracts published in English until July 2019. The use of VPR for UF therapy was identified by using the keywords: "uterine fibroids" and "vilaprisan".

RESULTS

In phase I and II clinical trials, VPR was shown to be effective in ameliorating UF-related clinical symptoms, especially abnormal or excessive uterine bleeding and in shrinking UFs. The tolerability of VPR is roughly similar to that of ulipristal acetate (UPA) and it tends to be more favorable than that of GnRH-agonists.

CONCLUSION

Presently, all trials examining the utility of VPR for the treatment of UF are halted; likely, due to the recently reported cases of hepato-toxicity with UPA, in addition to non reassuring toxicology results from preclinical long-term testing on rodents, carried out in parallel with late stage testing on humans. An accurate summary of robust data related to the safety of VPR is urgently needed to draw definitive conclusions on the future clinical development of this drug for UF therapy.

Sonographic and hysteroscopic endometrial examination in women treated with ulipristal acetate: Exploratory findings at a tertiary referral center

OBJECTIVE

Ulipristal acetate (UPA) is a progesterone receptor modulator (PRM) agent that has shown benefits in women with symptomatic uterine fibroids. However, its effects on the endometrium are complex and not fully understood. We describe exploratory findings on macroscopic observation of the endometrium at transvaginal sonography (TVS) and hysteroscopy. The aim of the study is to characterize endometrial patterns commonly observed after UPA treatment.

STUDY DESIGN

We performed a prospective longitudinal study at a tertiary referral center with 100 women with symptomatic uterine fibroids who received a 12-week treatment with UPA (5 mg/day). Patients underwent TVS before and after the treatment, and also a hysteroscopy examination was performed. Main outcome was to compare sonographic and hysteroscopic findings to histology after UPA treatment.

RESULTS

Twenty one out of 100 (21%) women showed PAEC confirmed by histology after UPA treatment. Ultrasound findings were normal in most women after UPA treatment, but 18/100 (18%) showed an endometrial pattern suggestive of PRM effects (non-uniform, homogeneous endometrium with regular cystic areas). Endometrial thickness ≥16 mm was detected in 6/100 patients (6%), and all of them also presented sonographic PRM pattern. No patient presented malignancy according to histology in this subgroup, and 100% of them had PAEC pattern at histology. Among total patient population showing PAEC at histology, only 33% of these were identified by hysteroscopy, while 57% were identified by TVS with the PRM suggestive pattern. Of note, visibility of endometrium was improved at TVS after UPA.

CONCLUSION

Identification of increased endometrial thickness together with the categorized endometrial PRM pattern at TVS may be correlated to benign lesions and may not be a cause of concern. This study is exploratory and further research is necessary to support these conclusions. Nevertheless, TVS seems to be feasible to plan adequate follow-up protocols by avoiding unnecessary interventional procedures such as hysteroscopy.

Influence of Ulipristal Acetate Therapy on Uterine Fibroid-Related Symptoms and on Uterine and Fibroid Volumes and Vascularity Indices Assessed by Ultrasound

OBJECTIVES

To investigate the modifications of uterine and fibroid volume, to study Doppler changes in uterine arteries and fibroid-supplying vessels, and to assess possible symptomatic relief after 3 months of treatment with ulipristal acetate.

METHODS

Forty-two premenopausal women with symptomatic fibroids were included in the study. They were evaluated clinically for the symptoms reported and underwent ultrasound examinations before starting treatment and after 3 months of therapy with ulipristal acetate. Transvaginal scanning was performed by the same sonographer, who measured the uterine volume and uterine artery pulsatility index and resistive index. Considering that some patients had more than 1 fibroid, the vascularization (supplying vessel pulsatility and resistive indices), locations, and sizes of a total of 73 fibroids were also recorded.

RESULTS

After 3 months of ulipristal acetate, patients had a significant improvement of all symptoms (P < .05). The percentage of uterine volume reduction was 14% (P = .03), with fibroid volume reduction of 32.8% (P = .01). Uterine artery vascular indices decreased after treatment, but their reduction did not reach significant results, whereas all fibroid vascular indices decreased significantly after 3 months of ulipristal acetate (P < .05). When the fibroids were divided according to their localization, all had significant volume reduction after therapy, but type 5 had the highest decrease (42%) compared to other fibroid types (P = .03).

CONCLUSIONS

Fibroid treatment with ulipristal acetate resulted in a significant improvement of fibroid-related symptoms; moreover, it proved to be effective in decreasing both uterine and fibroid volumes and fibroid vascularization. Type 5 fibroids seem to have the most major response to treatment.

Long-term intermittent pharmacological therapy of uterine fibroids - a possibility to avoid hysterectomy and its negative consequences

Uterine fibroids are found in almost 20-40% of women of reproductive age. For each woman an individualised treatment method should be applied because the hysterectomy procedure is not a good option in every case. The uterus is an organ necessary not only in reproduction. Its removal may result in: pelvic floor dysfunction and stress urinary incontinence, negative impair on life quality, depressive disorders, increased risk of cardiovascular and neurodegenerative diseases, and higher incidence of neoplastic disease. According to the last scientific reports, selective progesterone receptor modulators are the effective therapeutic option in uterine fibroids in women of reproductive age because progesterone is an important factor in their pathogenesis. Ulipristal acetate (UPA) is a progesterone receptor antagonist. It inhibits cell proliferation and angiogenesis in uterine fibroids and also reduces collagen deposits in extracellular matrix. Significant data concerning ulipristal acetate efficacy have been provided by scientific research, especially from the consecutive PEARL studies. Oral ulipristal acetate effectively and safely controls bleeding and pain in patients with symptomatic fibroids. It reduces fibroid volume and restores quality of life. The results of UPA long-term intermittent treatment are largely maintained during the off-treatment periods.