Selective progesterone receptor modulators: current applications and perspectives

Functionalized liposomes for targeted breast cancer drug delivery

Despite the exceptional progress in breast cancer pathogenesis, prognosis, diagnosis, and treatment strategies, it remains a prominent cause of female mortality worldwide. Additionally, although chemotherapies are effective, they are associated with critical limitations, most notably their lack of specificity resulting in systemic toxicity and the eventual development of multi-drug resistance (MDR) cancer cells. Liposomes have proven to be an invaluable drug delivery system but of the multitudes of liposomal systems developed every year only a few have been approved for clinical use, none of which employ active targeting. In this review, we summarize the most recent strategies in development for actively targeted liposomal drug delivery systems for surface, transmembrane and internal cell receptors, enzymes, direct cell targeting and dual-targeting of breast cancer and breast cancer-associated cells, e.g., cancer stem cells, cells associated with the tumor microenvironment, etc.

New Pharmacological Approaches to the Management of Premenstrual Dysphoric Disorder

Premenstrual symptoms are experienced by many female individuals during their fertile age. Premenstrual dysphoric disorder (PMDD), a sex-specific mood disorder, affects about 5% of female individuals during the luteal phase of the menstrual cycle. Treatment with selective serotonin reuptake inhibitors represents a valid solution to manage PMDD for many, but not all, patients. Owing to maladaptive neural reactivity to gonadal hormone fluctuations, that is, the putative mechanism postulated to underlie PMDD, drugs suppressing or stabilizing such variations have been tested. Recently, a clinically significant reduction in the severity of the mental symptoms of PMDD was observed upon treatment with a selective progesterone receptor modulator (SPRM), as demonstrated when comparing ulipristal acetate with placebo in a randomised controlled trial. Stable and low progesterone levels, with maintained low-medium oestradiol levels, define the endocrine profile of this treatment. Importantly, the efficacy of SPRM treatment was accompanied by negligible side effects. These promising results represent a headway to understanding the mechanisms behind PMDD symptomatology and opening up new solutions in the management of PMDD. They also call for studies on the long-term efficacy, safety, and viability of SPRMs in female individuals during their fertile age to further support the development of targeted management of female's mental ill-health in relation to the menstrual cycle. The present overview thus seeks to inform about current and new pharmacological approaches to the management of premenstrual dysphoric disorder.

Mechanisms of Drug Resistance and Use of Nanoparticle Delivery to Overcome Resistance in Breast Cancers

Breast cancer is the leading cancer type diagnosed among women in the world. Unfortunately, drug resistance to current breast cancer chemotherapeutics remains the main challenge for a higher survival rate. The recent progress in the nanoparticle platforms and distinct features of nanoparticles that enhance the efficacy of therapeutic agents, such as improved delivery efficacy, increased intracellular cytotoxicity, and reduced side effects, hold great promise to overcome the observed drug resistance. Currently, multifaceted investigations are probing the resistance mechanisms associated with clinical drugs, and identifying new breast cancer-associated molecular targets that may lead to improved therapeutic approaches with the nanoparticle platforms. Nanoparticle platforms including siRNA, antibody-specific targeting and the role of nanoparticles in cellular processes and their effect on breast cancer were discussed in this article.

Next generation strategies for preventing preterm birth

Preterm birth (PTB) is defined as delivery before 37 weeks of gestation. Globally, 15 million infants are born prematurely, putting these children at an increased risk of mortality and lifelong health challenges. Currently in the U.S., there is only one FDA approved therapy for the prevention of preterm birth. Makena is an intramuscular progestin injection given to women who have experienced a premature delivery in the past. Recently, however, Makena failed a confirmatory trial, resulting the Center for Drug Evaluation and Research's (CDER) recommendation for the FDA to withdrawal Makena's approval. This recommendation would leave clinicians with no therapeutic options for preventing PTB. Here, we outline recent interdisciplinary efforts involving physicians, pharmacologists, biologists, chemists, and engineers to understand risk factors associated with PTB, to define mechanisms that contribute to PTB, and to develop next generation therapies for preventing PTB. These advances have the potential to better identify women at risk for PTB, prevent the onset of premature labor, and, ultimately, save infant lives.

Ulipristal Acetate for Treatment of Premenstrual Dysphoric Disorder: A Proof-of-Concept Randomized Controlled Trial

OBJECTIVE

Premenstrual dysphoric disorder (PMDD) is a common mood disorder, characterized by distressing affective, behavioral, and somatic symptoms in the late luteal phase of the menstrual cycle. The authors investigated continuous treatment with a selective progesterone receptor modulator, ulipristal acetate (UPA), as a potential treatment for PMDD.

METHODS

The authors conducted an investigator-initiated, multicenter, double-blind, randomized, parallel-group clinical trial in which women with PMDD (N=95) were treated with either 5 mg/day of UPA or placebo during three 28-day treatment cycles. The primary outcome was the change in premenstrual total score on the Daily Record of Severity of Problems (DRSP) from baseline to end of treatment. DRSP scores were captured by daily ratings using a smartphone application and were analyzed with linear mixed models for repeated measures.

RESULTS

The mean improvement in DRSP score after 3 months was 41% (SD=18) in the UPA group, compared with 22% (SD=27) in the placebo group (mean difference -18%; 95% CI=-29, -8). Treatment effects were also noted for the DRSP depressive symptom subscale (42% [SD=22] compared with 22% [SD=32]) and the DRSP anger/irritability subscale (47% [SD=21] compared with 23% [SD=35]), but not for the DRSP physical symptom subscale. Remission based on DRSP score was attained by 20 women in the UPA group (50.0%) and eight women in the placebo group (21.1%) (a statistically significant difference).

CONCLUSIONS

If these results are replicated, UPA could be a useful treatment for PMDD, particularly for the psychological symptoms associated with the disorder.

Novel RU486 (mifepristone) analogues with increased activity against Venezuelan Equine Encephalitis Virus but reduced progesterone receptor antagonistic activity

There are currently no therapeutics to treat infection with the alphavirus Venezuelan equine encephalitis virus (VEEV), which causes flu-like symptoms leading to neurological symptoms in up to 14% of cases. Large outbreaks of VEEV can result in 10,000 s of human cases and mass equine death. We previously showed that mifepristone (RU486) has anti-VEEV activity (EC50 = 20 μM) and only limited cytotoxicity (CC50 > 100 μM), but a limitation in its use is its abortifacient activity resulting from its ability to antagonize the progesterone receptor (PR). Here we generate a suite of new mifepristone analogues with enhanced antiviral properties, succeeding in achieving >11-fold improvement in anti-VEEV activity with no detectable increase in toxicity. Importantly, we were able to derive a lead compound with an EC50 of 7.2 µM and no detectable PR antagonism activity. Finally, based on our SAR analysis we propose avenues for the further development of these analogues as safe and effective anti-VEEV agents.