A New Sustained-release, 3-Month Leuprolide Acetate Formulation Achieves and Maintains Castrate Concentrations of Testosterone in Patients With Prostate Cancer

Investigations of Long-Acting Formulations in Children, Adolescents, and Pregnant Women: A Systematic Review

Background/Objectives: Long-acting and extended-release drug delivery strategies have greatly improved treatment for a variety of medical conditions. Special populations, specifically infants, children, young people, and pregnant and postpartum women, could greatly benefit from access to these strategies but are often excluded from clinical trials. We conducted a systematic review of all clinical studies involving the use of a long-acting intramuscular injection or implant in infants, children, young people, and pregnant and postpartum people. Methods: Pubmed, Embase, and Cochrane Library trials were searched. Studies published from 1980 through 2018 were included. After abstract review and duplication removal, full-text articles were obtained for further review, reviewed by two independent reviewers, and disagreements were resolved by a third reviewer. Results: a total of 101 studies of long-acting therapeutics were completed in these populations, and most (80%) of these had a sample size of <100 individuals. Therapeutics for only a small pool of indications were examined in these studies, with 72% of the studies investigating hormonal contraception or other types of hormonal treatments. Only 9.3% of the studies in children and 16.7% of the studies in pregnant people collected any pharmacokinetic (PK) data. Conclusions: Long-acting formulations may behave differently (both pharmacokinetically and pharmacodynamically) in childhood, adolescence, and pregnancy as compared to non-pregnant adulthood. Therefore, it is imperative to increase and improve upon the studies investigating long-acting formulations in order to close the knowledge gap and improve care and treatment in these special populations.

Effectiveness, pharmacokinetics, and safety of triptorelin acetate microspheres in patients with locally advanced and metastatic prostate cancer

Background

A newly generic microspheres, sustained-release formulation of triptorelin acetate 3.75 mg has been developed.

Objectives

To evaluate the efficacy, pharmacokinetics, and safety of triptorelin 1-month formulation in Chinese patients with prostate cancer.

Design

An open-label, multicenter clinical trial with one arm testing a 1-month sustained-release triptorelin formulation in prostate cancer patients.

Methods

Patients with prostate cancer received three consecutive 28-day injections of triptorelin acetate. The primary endpoint was the proportion of successful patients over the total number of evaluable patients. Treatment success was defined as testosterone suppression below the clinical castration level (i.e., <0.5 ng/mL) at day 28 and maintenance of clinical castration until study completion (day 84). The frequency of patients with testosterone concentrations <0.2 ng/mL was also studied.

Results

The study included 125 patients. All 125 patients received at least one dose of the study drug and 122 completed the study. The successful patient proportion among the evaluable patients was 97.6% (122/125; 95% CI, 92.7-99.2). 95.1% (116/122) achieved testosterone concentrations <0.2 ng/mL. The pharmacokinetic profile of triptorelin during the first 3 months of treatment, evaluated in a subset of the study population (n = 11), showed sustained release of triptorelin from the formulation. Values for AUC0-τ calculated from day 0 to 28, and day 56 to 84 were 134.42 (28.76), and 154.72 (21.86) h*ng/mL, respectively. The most common treatment-related adverse events were increased alanine aminotransferase (18.4%), increased aspartate aminotransferase (16.0%), and hot flashes (9.6%). Prolonged QT interval on electrocardiogram, erectile dysfunction, and decreased libido each occurred in ⩽4% of the patients. The frequently reported local adverse reaction was pain at the injection site, experienced by 2.4% (3/125) of the patients.

Conclusion

3.75-mg Triptorelin acetate microspheres for injection were effective in achieving and maintaining testosterone suppression and were well tolerated in patients with prostate cancer.

Trial registration

chictr.org.cn (ChiCTR2000033188).

In-situ forming PLGA implants: Towards less toxic solvents

In-situ forming poly(lactic-co-glycolic acid) (PLGA) implants offer a great potential for controlled drug delivery for a variety of applications, e.g. periodontitis treatment. The polymer is dissolved in a water-miscible solvent. The drug is dissolved or dispersed in this solution. Upon contact with aqueous body fluids, the solvent diffuses into the surrounding tissue and water penetrates into the formulation. Consequently, PLGA precipitates, trapping the drug. Often, N-methyl-2-pyrrolidine (NMP) is used as a water-miscible solvent. However, parenteral administration of NMP raises toxicity concerns. The aim of this study was to identify less toxic alternative solvent systems for in-situ forming PLGA implants. Various blends of polyethylene glycol 400 (PEG 400), triethyl citrate (TEC) and ethanol were used to prepare liquid formulations containing PLGA, ibuprofen (as an anti-inflammatory drug) and/or chlorhexidine dihydrochloride (as an antiseptic agent). Implant formation and drug release kinetics were monitored upon exposure to phosphate buffer pH 6.8 at 37 °C. Furthermore, the syringeability of the liquids, antimicrobial activity of the implants, and dynamic changes in the latter's wet mass and pH of the release medium were studied. Importantly, 85:10:5 and 60:30:10 PEG 400:TEC:ethanol blends provided good syringeability and allowed for rapid implant formation. The latter controlled ibuprofen and chlorhexidine release over several weeks and assured efficient antimicrobial activity. Interestingly, fundamental differences were observed concerning the underlying release mechanisms of the two drugs: Ibuprofen was dissolved in the solvent mixtures and partially leached out together with the solvents during implant formation, resulting in relatively pronounced burst effects. In contrast, chlorhexidine dihydrochloride was dispersed in the liquids in the form of tiny particles, which were effectively trapped by precipitating PLGA during implant formation, leading to initial lag-phases for drug release.

Clinical Efficacy, Pharmacokinetics, and Safety of the Available Medical Options in the Treatment of Endometriosis-Related Pelvic Pain: A Scoping Review

BACKGROUND

In this scoping review, we sought to identify published studies evaluating the drugs currently used in the treatment of endometriosis-related pelvic pain, with reflection on their chemical properties, pharmacokinetics, safety profile, and clinical efficacy.

METHODS

A literature search was conducted with the use of the PubMed and EMBASE electronic databases, focusing on identifying articles published in English between January 1990 and 2023.

RESULTS

Based on the included studies, current therapy options for the treatment of endometriosis-related pain identified and reviewed in this article were: (1) non-steroidal anti-inflammatory drugs; (2) combined oral contraceptive (COCs); (3) progestins; (4) gonadotropin-releasing hormone agonists and antagonists; (5) aromatase inhibitors (AIs); (6) selective estrogen and progesterone receptor modulators; and (7) levonorgestrel-intrauterine device.

CONCLUSIONS

Based on the published evidence, clinicians should consider NSAIDs, COCs, and progestins as the first-line medical therapies. Compared with second-line options, such as GnRH agonists/antagonists or AIs, the abovementioned first-line options are well tolerated, efficacious, and exhibit lower overall price. Future research priorities should be to identify novel target therapies and to evaluate the effects of available drugs through different routes of administration.

Long-acting injectable PLGA/PLA depots for leuprolide acetate: successful translation from bench to clinic

The excellent properties of polyesters combined with their ease of synthesis and modification enabled their wide use in the pharmaceutical industry. This has been translated into the approval of several injectable depots for clinical use. Long-acting depots for leuprolide acetate were among the first and most successful examples including Lupron Depot^® and ELIGARD^®. Studying these products is of great interest for researchers in both industry and academia. This will undoubtedly pave the road for the development of new as well as generic long-acting depots for a variety of drugs.

Accelerating Digitalization in Healthcare with the InSilicoTrials Cloud-Based Platform: Four Use Cases

The use of in silico trials is expected to play an increasingly important role in the development and regulatory evaluation of new medical products. Among the advantages that in silico approaches offer, is that they permit testing of drug candidates and new medical devices using virtual patients or computational emulations of preclinical experiments, allowing to refine, reduce or even replace time-consuming and costly benchtop/in vitro/ex vivo experiments as well as the involvement of animals and humans in in vivo studies. To facilitate and widen the adoption of in silico trials, InSilicoTrials Technologies has developed a cloud-based platform, hosting healthcare simulation tools for different bench, preclinical and clinical evaluations, and for diverse disease areas. This paper discusses four use cases of in silico trials performed using the InSilicoTrials.com platform. The first application illustrates how in silico approaches can improve the early preclinical assessment of drug-induced cardiotoxicity risks. The second use case is a virtual reproduction of a bench test for the safety assessment of transcatheter heart valve substitutes. The third and fourth use cases are examples of virtual patients generation to evaluate treatment effects in multiple sclerosis and prostate cancer patients, respectively.

Advanced delivery of leuprorelin acetate for the treatment of prostatic cancer

INTRODUCTION

Androgen-deprivation therapy (ADT) is the main therapy for patients with advanced and metastatic prostate cancer (PCa) and, in combination with radiotherapy, for patients with localized high-risk PCa. Due to its favorable tolerability among different treatments available for ADT, leuprorelin acetate is well established as the leading luteinizing hormone-releasing hormone (LHRH) analog. The development of second-generation leuprorelin acetate (LA) depot formulation (Eligard®, Recordati S.p.A) allowed a consistent and controlled release of leuprorelin between injections and a more efficient reduction of testosterone levels with respect to conventional LHRH agonists.

AREAS COVERED

This work provides a summary of the biological and clinical rationale for using LA to manage PCa and presents the current evidence about the therapeutic activity of the LA gel depot formulation, used as an advanced leuprorelin acetate delivery method.

EXPERT OPINION

Results of the registration studies and post-marketing clinical trials demonstrate that the LA gel depot provides long-term efficacy in the clinical practice and a good degree of tolerability. Overall, collected data suggest that the LA gel depot can represent the ADT reference therapy in advanced PCa.

Preferences of Persons with or at Risk for Hepatitis C for Long-Acting Treatments

BACKGROUND

Whereas safe, curative treatments for hepatitis C virus (HCV) have been available since 2015, there are still 58 million infected persons worldwide, and global elimination may require new paradigms. We sought to understand the acceptability of long-acting HCV treatment approaches.

METHODS

A cross-sectional, 43-question survey was administered to 1457 individuals with HCV or at risk of HCV at 28 sites in 9 countries to assess comparative interest in a variety of long-acting strategies in comparison to oral pills.

RESULTS

Among HCV-positive participants, 37.7% most preferred an injection, 5.6% an implant, and 6% a gastric residence device, as compared to 50.8% who stated they would most prefer taking 1 to 3 pills per day. When compared directly to taking pills, differences were observed in the relative preference for an injection based on age (p<0.001), location (p<0.001), and prior receipt of HCV treatment (p=0.005), but not sex. When an implant was compared to pills, greater preference was represented by women (p=0.01) and adults of younger ages (p=0.012 per 5 years). Among participants without HCV, 49.5% felt that injections are stronger than pills, and 34.7% preferred taking injections to pills. Among those at-risk participants who had received injectable medications in the past, 123 out of 137 (89.8%) expressed willingness to receive one in the future.

CONCLUSIONS

These data point to high acceptability of long-acting treatments, which for a substantial minority, might even be preferred to pills for the treatment of HCV infection. Long-acting treatments for HCV infection might contribute to global efforts to eliminate hepatitis C.

Pharmacokinetic and pharmacodynamic evaluation of the new prolonged-release leuprorelin acetate microspheres for injection compared with Enantone® in healthy Chinese male volunteers

PURPOSE

To compare the pharmacokinetics, pharmacodynamics and safety of the new prolonged-release leuprorelin acetate microspheres for injection (3.75 mg) with the reference product Enantone® (3.75 mg).

METHOD

48 healthy male volunteers were enrolled and randomly received a single 3.75 mg dose of the test drug or Enantone®.

RESULTS

There were no significant differences in C_max, AUC_0-t and AUC_0-48 between the test group and reference group (P > 0.05). The 90% confidence intervals of the two groups were 87.49%~112.74%, 97.15%~154.25%, and 80.85%~109.01%, respectively. Twenty-eight days after administration, both groups reached 100.0% castration level; there was no difference in the time from administration to reaching castration level between the two groups (P > 0.05); However, the difference between the two groups in the duration of castration level was statistically significant (P < 0.05). There were no major or serious adverse events, and the severity was mild to moderate.

CONCLUSION

The pharmacokinetic characteristics of leuprorelin in two groups were consistent. The two groups exhibited similar inhibitory effects on testosterone and more subjects in the test group maintained a longer castration time than those in the reference group.

Current Status and Future Perspectives of Androgen Receptor Inhibition Therapy for Prostate Cancer: A Comprehensive Review

The androgen receptor (AR) is one of the main components in the development and progression of prostate cancer (PCa), and treatment strategies are mostly directed toward manipulation of the AR pathway. In the metastatic setting, androgen deprivation therapy (ADT) is the foundation of treatment in patients with hormone-sensitive prostate cancer (HSPC). However, treatment response is short-lived, and the majority of patients ultimately progress to castration-resistant prostate cancer (CRPC). Surmountable data from clinical trials have shown that the maintenance of AR signaling in the castration environment is accountable for disease progression. Study results indicate multiple factors and survival pathways involved in PCa. Based on these findings, the alternative molecular pathways involved in PCa progression can be manipulated to improve current regimens and develop novel treatment modalities in the management of CRPC. In this review, the interaction between AR signaling and other molecular pathways involved in tumor pathogenesis and its clinical implications in metastasis and advanced disease will be discussed, along with a thorough overview of current and ongoing novel treatments for AR signaling inhibition.

The Androgen Receptor in Prostate Cancer: Effect of Structure, Ligands and Spliced Variants on Therapy

The androgen receptor (AR) plays a predominant role in prostate cancer (PCa) pathology. It consists of an N-terminal domain (NTD), a DNA-binding domain (DBD), a hinge region (HR), and a ligand-binding domain (LBD) that binds androgens, including testosterone (T) and dihydrotestosterone (DHT). Ligand binding at the LBD promotes AR dimerization and translocation to the nucleus where the DBD binds target DNA. In PCa, AR signaling is perturbed by excessive androgen synthesis, AR amplification, mutation, or the formation of AR alternatively spliced variants (AR-V) that lack the LBD. Current therapies for advanced PCa include androgen synthesis inhibitors that suppress T and/or DHT synthesis, and AR inhibitors that prevent ligand binding at the LBD. However, AR mutations and AR-Vs render LBD-specific therapeutics ineffective. The DBD and NTD are novel targets for inhibition as both perform necessary roles in AR transcriptional activity and are less susceptible to AR alternative splicing compared to the LBD. DBD and NTD inhibition can potentially extend patient survival, improve quality of life, and overcome predominant mechanisms of resistance to current therapies. This review discusses various small molecule and other inhibitors developed against the DBD and NTD—and the current state of the available compounds in clinical development.