Lanreotide Depot: An Antineoplastic Treatment of Carcinoid or Neuroendocrine Tumors

Cyclic peptides: A powerful instrument for advancing biomedical nanotechnologies and drug development

Cyclic peptides have emerged as an essential tool in the advancement of biomedical nanotechnologies, offering unique structural and functional advantages over linear peptides. This review article aims to highlight the roles of cyclic peptides in the development of biomedical fields, with a particular focus on their application in drug discovery and delivery. Cyclic peptides exhibit exceptional stability, bioavailability, and binding specificity, making them ideal candidates for therapeutic and diagnostic applications. We explore the synthesis and design strategies that enable the precise control of cyclic peptide structures, leading to enhanced performance in targeting specific cellular pathways. The article also highlights recent breakthroughs in the use of cyclic peptides for creating innovative drug delivery systems, including nanoparticle conjugates and peptide-drug conjugates, which have shown promise in improving the efficacy and safety profiles of existing traditional treatments. The integration of cyclic peptides into nanotechnological frameworks holds significant promise for addressing unmet medical needs, providing a foundation for future advancements in personalized medicine and targeted drug delivery.

β-Cyclodextrin Derivatives Bind Aromatic Side Chains of the Cyclic Peptide Lanreotide

Cyclodextrin complexation has a potential to modulate the physicochemical properties of peptide drugs. The ability of peptides to form an inclusion complex can be influenced by factors such as size, amino acid sequence of peptide and the size and charge of the cyclodextrin cavity. In this study, the inclusion complexes of cyclic peptide drug lanreotide acetate with two common β-cyclodextrin derivatives, Sulfobutyl ether β-CD (SBEβ-CD) and hydroxypropyl β-CD (HPβ-CD) were investigated. NMR spectroscopy was used to examine the interaction between β-cyclodextrin derivatives and specific residues of lanreotide. It was observed that the hydrophobic side chain of aromatic residues in the lanreotide sequence can be fit into the cavity of both β-cyclodextrin derivatives. Additionally, NMR revealed a lower diffusion coefficient and higher hydrodynamic radius of complex, indicative of binding to the cavities. Each aromatic residue was individually studied by substituting alanine in lanreotide to measure its association binding with both β-cyclodextrin derivatives. The alanine-substitute study indicated a stronger binding of SBEβ-CD to Lanreotide compared to HPβ-CD. Docking studies suggested that the 1:1 inclusion complex is more favorable than higher order complexes due to the steric hindrance and size considerations. The docking analysis indicated the stable conformation of all three aromatic side chains with both β-cyclodextrin derivatives, SBEβ-CDand HPβ-CD.

On-resin synthesis of Lanreotide epimers and studies of their structure-activity relationships

Peptide drugs often accompany epimeric impurities (isomers). Therefore, efficient chemical synthesis of epimers is critical to identify them correctly and investigate their biological activities. Here, we report the rapid synthesis and structure-activity relationship (SAR) studies of eight possible epimers of a somatostatin synthetic analog (SSA), lanreotide (LAN). SPPS and the subsequent on-resin rapid disulfide closure method offered >90% conversion yield for all epimers (P1-P8). Further, we developed an analytical method to separate these epimers, which enabled the profiling of five epimeric impurities in the API, purchased for Somatuline generic formulations. In SAR studies, most LAN epimers revealed compromised antiproliferative activity, while the P7 epimer retained antiproliferative activity similar to LAN API, as supported by in silico SAR studies in detail. Additionally, P7 showed serum stability nearly identical to LAN, suggesting that drug epimers could be a potential API. Current studies will further encourage the development of novel SSA scaffolds.

Sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent-based capsule phase microextraction device combined with HPLC/post-column derivatization for the determination of lanreotide, a human somatostatin analogue in urine

In this research, a sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent-based capsule phase microextraction (CPME) device was developed in combination with liquid chromatography-post column derivatization for the first ever reported determination of a somatostatin analogue - lanreotide in human urine. The sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent was encapsulated in the lumen of a polypropylene capillary tube and characterized by FT-IR spectroscopy and SEM with energy dispersive X-ray spectroscopy (EDS). The main steps of the CPME workflow were optimized to obtain high extraction efficiency for the target analyte. After the separation of the analyte on a C8 stationary phase, the peptide was derivatized online with o-phthalaldehyde before the fluorescence detection. The main experimental parameters of CPME and the post-column procedures were systematically investigated and optimized. The method was validated in terms of selectivity, linearity, accuracy, precision, limits of detection (LOD), and limits of quantification (LOQ). The relative bias ranged between 88.8 and 115.6 % for the peptide, while the RSD values for repeatability and intermediate precision were less than 14.3 %. The achieved limit of detection (LOD) was 0.2 μΜ while the limit of quantitation (LOQ) was established as 0.9 μΜ. Finally, the sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent-based microextraction capsules were found to be reusable for at least 20 extractions. The developed method presented adequate overall performance, and it could be applied in the analysis of selected peptide in human urine samples.

Case Report: Carcinoid heart disease with severe tricuspid regurgitation and concomitant patent foramen ovale causing severe hypoxia

This case report demonstrates a unique case of managing complex concomitant structural cardiac issues using transcatheter techniques in a frail patient. The primary regurgitant lesion in this case caused significant right to left shunting with severely debilitating hypoxaemia for the patient, requiring high volumes of ambulatory oxygen to compensate. We would like to highlight the role of multi-modality cardiac imaging demonstrated in this case, as well as the limited surgical data and poor outcomes in advanced disease with higher peri-operative complications. Finally, it should be noted that percutaneous correction of structural lesions may provide palliative relief but carries an uncertain risk of recurrence.

A phase II trial of lanreotide for the prevention of postoperative pancreatic fistula

BACKGROUND

Clinically relevant postoperative pancreatic fistula (CR-POPF) is a significant contributor to morbidity after pancreatectomy. Somatostatin analogues have shown variable efficacy in the prevention of CR-POPF. Lanreotide is a somatostatin analogue ideally suited for perioperative use due to its long half-life and favorable side effect profile.

METHODS

We conducted a phase II single-arm trial of a single dose of preoperative lanreotide (120 mg) in patients undergoing either pancreaticoduodenectomy (PD) or distal pancreatectomy (DP). The primary outcome was development of CR-POPF or intra-abdominal abscess. Secondary outcomes included biochemical leak and overall morbidity.

RESULTS

A total of 98 patients completed the study. Sixty-two underwent PD (63.3%) and 36 underwent DP (36.7%). The primary outcome was observed in eight (8%) patients in the overall cohort, one from the DP group and seven from the PD group. Biochemical leak was detected in 12 (12.2%) patients in the overall cohort. Twenty-seven (27.5%) patients developed complications, of which 14 (14.2%) were major complications. Drug-related adverse events were limited to mild skin reactions in two (2%) patients.

CONCLUSION

Patients who received preoperative lanreotide developed CR-POPF at rates significantly lower than historical controls or published literature. This provides strong justification for a randomized controlled trial.

The industrial design, translation, and development strategies for long-acting peptide delivery

INTRODUCTION

Peptides are widely recognized as therapeutic agents in the treatment of a wide range of diseases, such as cancer, diabetes etc. However, their use has been limited by their short half-life, due to significant metabolism by exo- and endo-peptidases as well as their inherent poor physical and chemical stability. Research with the aim of improving their half-life in the body, and thus improving patient compliance (by decreasing the frequency of injections) has gained significant attention.

AREAS COVERED

This review outlines the current landscape and industrial approaches to achieve extended peptide exposure and reduce dosing frequency. Emphasis is placed on identifying challenges in drug product manufacturing and desirable critical quality attributes that are essential for activity and safety, providing insights into chemistry and design aspects impacting peptide release, and summarizing important considerations for CMC developability assessments of sustained release peptide drugs.

EXPERT OPINION

Bring the patient and disease perspective early into development. Substantial advances have been made in the field of sustained delivery of peptides despite their complexity. The article will also highlight considerations for early-stage product design and development, providing an industrial perspective on risk mitigation in developing sustained release peptide drug products.

Bioanalysis of lanreotide in dog plasma using liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study of beagle dogs after single subcutaneous injection

Lanreotide is similar to a naturally occurring hormone, somatostatin; thus, it may be used to treat acromegaly or metastatic gastroenteropancreatic neuroendocrine tumours. Here, a bioanalytical method coupling ultra-performance liquid chromatography with tandem mass spectrometry to quantify lanreotide and an internal standard (IS) was developed and validated in dog plasma. The plasma samples were extracted using typical protein precipitation processes. The analyte and internal standard were separated on Phenomenex Kinetex® C18 with 0.1% formic acid and acetonitrile in the mobile phase at a flow rate of 0.4 mL/min. The fragmentation of precursor ions to product ions was optimized at m/z 548.8 → 170.0 for lanreotide [M + 2H]²⁺ and 472.2 → 436.2 for IS [M + H]⁺. The peak retention times of lanreotide and IS were 1.09 min and 1.22 min, respectively. The calibration curve samples in dog plasma ranged from 0.3 to 1000 ng/mL and showed good linearity, with a correlation coefficient of r²=0.9996. The lower limit of quantitation was 0.3 ng/mL. The intra- and inter-day precision (relative standard deviation) values for each quality control level were < 9.7 % and < 9.3 %, respectively; intra- and inter-day accuracy were < 109.3% and < 110.4%, respectively. Lanreotide in dog plasma was stable in various conditions. The maximum plasma concentration of lanreotide in male beagle dogs after subcutaneous injection of Somatuline® (lanreotide) Autogel 120 mg was 88.1 ng/mL. The half-life (T_1/2) of lanreotide in beagle dogs was long, approximately 198.6 h; the area under the plasma-concentration curve from 0 to 840 h (day 35) was 6,995 ng⋅h/mL. This novel quantification method using UPLC-MS/MS was successfully applied to the pharmacokinetic analysis of lanreotide in dog plasma. The results will assist future studies of drug formulation and repurposing.

Self-Assembling Peptides: From Design to Biomedical Applications

Self-assembling peptides could be considered a novel class of agents able to harvest an array of micro/nanostructures that are highly attractive in the biomedical field. By modifying their amino acid composition, it is possible to mime several biological functions; when assembled in micro/nanostructures, they can be used for a variety of purposes such as tissue regeneration and engineering or drug delivery to improve drug release and/or stability and to reduce side effects. Other significant advantages of self-assembled peptides involve their biocompatibility and their ability to efficiently target molecular recognition sites. Due to their intrinsic characteristics, self-assembled peptide micro/nanostructures are capable to load both hydrophobic and hydrophilic drugs, and they are suitable to achieve a triggered drug delivery at disease sites by inserting in their structure's stimuli-responsive moieties. The focus of this review was to summarize the most recent and significant studies on self-assembled peptides with an emphasis on their application in the biomedical field.

Preoperative and long-term efficacy and safety of lanreotide autogel in patients with thyrotropin-secreting pituitary adenoma: a multicenter, single-arm, phase 3 study in Japan

Somatostatin analogs are recommended for pharmacotherapy of TSH-secreting pituitary adenoma (TSHoma). A multicenter clinical trial was conducted to evaluate the efficacy and safety of lanreotide autogel treatment for TSHoma. A total of 13 Japanese patients with TSHoma were enrolled from February to December 2018 and treated with lanreotide autogel 90 mg every 4 weeks, with dose adjustments to 60 mg or 120 mg. Analysis was performed on data from patients receiving preoperative treatment (n = 6) up to 24 weeks and from those receiving primary or postoperative treatment (n = 7) up to 52 weeks. The primary efficacy endpoints were serum concentrations of TSH, free triiodothyronine (FT3), and free thyroxine (FT4). The secondary efficacy endpoints were pituitary tumor size and clinical symptoms. The serum concentrations of TSH, FT3, and FT4 decreased with treatment, and euthyroid status was maintained until final assessment. FT4 at final assessment was within reference ranges in 10/13 patients. The median (interquartile range) percent change in pituitary tumor size from baseline at final assessment was -23.8% (-38.1, -19.8). The clinical symptoms were also improved. The patients receiving preoperative treatment did not develop perioperative thyroid storm. Regarding safety, adverse events were observed in 12/13 patients, but none discontinued treatment. The common adverse events were gastrointestinal disorders (12/13 patients) and administration site reactions (5/13 patients). Lanreotide autogel may be effective for controlling thyroid function and reducing the pituitary tumor size, and is tolerable in patients with TSHoma (Japic Clinical Trials Information; JapicCTI-173772).

Sustained Release Systems for Delivery of Therapeutic Peptide/Protein

Peptide/protein therapeutics have been significantly applied in the clinical treatment of various diseases such as cancer, diabetes, etc. owing to their high biocompatibility, specificity, and therapeutic efficacy. However, due to their immunogenicity, instability stemming from its complex tertiary and quaternary structure, vulnerability to enzyme degradation, and rapid renal clearance, the clinical application of protein/peptide therapeutics is significantly confined. Though nanotechnology has been demonstrated to prevent enzyme degradation of the protein therapeutics and thus enhance the half-life, issues such as initial burst release and uncontrollable release kinetics are still unsolved. Moreover, the traditional administration method results in poor patient compliance, limiting the clinical application of protein/peptide therapeutics. Exploiting the sustained-release formulations for more controllable delivery of protein/peptide therapeutics to decrease the frequency of injection and enhance patient compliance is thus greatly meaningful. In this review, we comprehensively summarize the substantial advancements of protein/peptide sustained-release systems in the past decades. In addition, the advantages and disadvantages of all these sustained-release systems in clinical application together with their future challenges are also discussed in this review.

Challenges and opportunities in the delivery of cancer therapeutics: update on recent progress

Global cancer prevalence has continuously increased in the last decades despite substantial progress achieved for patient care. Cancer is no longer recognized as a singular disease but as a plurality of different ones, leading to the important choice of the drug administration route and promoting the development of novel drug-delivery systems (DDS). Due to their structural diversity, therapeutic cancer drugs present specific challenges in physicochemical properties that can adversely affect their efficacy and toxicity profile. These challenges are addressed by innovative DDS to improve bioavailability, pharmacokinetics and biodistribution profiles. Here, we define the drug delivery challenges related to oral, intravenous, subcutaneous or alternative routes of administration, and review innovative DDS, marketed or in development, that answer those challenges.

Just how prevalent are peptide therapeutic products? A critical review

How prevalent are peptide therapeutic products? How innovative are the formulations used to deliver peptides? This review provides a critical analysis of therapeutic peptide products and the formulations approved by the United States Food and Drug administration (FDA), the European Medicines Agency (EMA), and the Japanese Pharmaceuticals and Medical Devices Agency (PMDA). This review also provides an in-depth analysis of dosage forms and administration routes for delivering peptide therapeutics, including injectables, oral dosage forms, and other routes of administration. We discuss the function of excipients in parenteral formulations in detail, since most peptide therapeutics are parenterally administered. We provide case studies of alternate delivery routes and dosage forms. Based on our analysis, therapeutic peptides administered as injectables remain the most commonly used dosage forms, particularly in the form of subcutaneous, intravenous, or intramuscular injections. In addition, therapeutic peptides are formulated to achieve prolonged release, often through the use of polymer carriers. The limited number of oral therapeutic peptide products and their poor absorption and subsequent low bioavailability indicate a need for new technologies to broaden the formulation design space. Therapeutic peptide products may also be delivered through other administration routes, including intranasal, implant, and sublingual routes. Therefore, an in-depth understanding of how therapeutic peptides are now formulated and administered is essential to improve peptide delivery, improve patient compliance, and reduce the healthcare burden for these crucial therapeutic agents.

The Chemical Methods of Disulfide Bond Formation and Their Applications to Drug Conjugates

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The disulfide bond possesses unique chemical and biophysical properties which distinguish it as one of the key structural elements of bioactive proteins and peptides, important drugs and other materials. The chemo-selective synthesis of these structures and the exploration of their function have been of longstanding interest to the chemistry community. The past decades have witnessed significant progress in both areas. This review will summarize the historically established and recently developed chemical methods in disulfide bond formation. The discussion will also be extended to the use of the disulfide linkers in small molecules, and peptide- and protein-drug conjugates. It is hoped that the combined overview of the fundamental chemistries and applications to drug discovery will inspire creative thinking and stimulate future novel uses of these versatile chemistries.

Selective internal radiation therapy: an effective treatment for hormonal syndromes in pancreatic neuroendocrine tumors

The hormone secretion in pancreatic neuroendocrine tumors (pNET) causes an important interference in patients' quality of life. We present two cases of pNET metastatic to the liver (a pancreatic endocrine carcinoma with a severe hormonal syndrome and an insulinoma with severe crisis of hypoglycemia and coma) refractory to conventional treatments, which were finally solved with selective internal radiation therapy (SIRT), a nonstandard level 1 therapy. We show two examples of an excellent control of symptoms together with a long survival after treatment with SIRT. The evidence supporting the use of this therapy is level 2. Our case reports strongly support the use of SIRT for the severe clinical syndrome in pNET metastatic to the liver and refractory to somatostatin analogs.

A Comprehensive Map of FDA-Approved Pharmaceutical Products

With the increasing research and development (R&D) difficulty of new molecular entities (NMEs), novel drug delivery systems (DDSs) are attracting widespread attention. This review investigated the current distribution of Food and Drug Administration (FDA)-approved pharmaceutical products and evaluated the technical barrier for the entry of generic drugs and highlighted the success and failure of advanced drug delivery systems. According to the ratio of generic to new drugs and the four-quadrant classification scheme for evaluating the commercialization potential of DDSs, the results showed that the traditional dosage forms (e.g., conventional tablets, capsules and injections) with a lower technology barrier were easier to reproduce, while advanced drug delivery systems (e.g., inhalations and nanomedicines) with highly technical barriers had less competition and greater market potential. Our study provides a comprehensive insight into FDA-approved products and deep analysis of the technical barriers for advanced drug delivery systems. In the future, the R&D of new molecular entities may combine advanced delivery technologies to make drug candidates into more therapeutically effective formulations.

Challenges in oral peptide delivery: lessons learnt from the clinic and future prospects

Therapeutic peptides have become very successful drugs due to their specificity, potency and low toxicity, but they show challenges for their delivery, due to their short half-life and rapid plasma clearance. For these reasons, peptides are usually administered using injectable sustained-release formulations. Oral peptide route is highly compelling from a patient and commercial point of view. However, poor peptide stability and low permeability across the intestinal epithelium still make it very challenging to effectively deliver peptides by the oral route. In this paper, biopharmaceutical and formulation features of oral peptides, as well as key clinical outcomes, are reviewed and discussed in the perspective of designing next generation of oral peptide formulations for a true paradigm shift.

Structural Characterization of PEGylated Hexaphenylalanine Nanostructures Exhibiting Green Photoluminescence Emission

Peptides containing aromatic residues are known to exhibit spontaneous phenomena of supramolecular organization into ordered nanostructures (NSs). In this work we studied the structural behavior and optoelectronic properties of new biocompatible materials obtained by the self-assembly of a series of hexaphenylalanines (F6) modified at the N terminus by a PEG chain of different lengths. PEG₁₂ -F6, PEG₁₈ -F6, and PEG₂₄ -F6 peptides were synthesized by coupling sequentially two, three, or four units of amino-carboxy-PEG₆ blocks, each one containing six oxyethylene repetitions. Changes in the length and composition of the PEG chain were found to modulate the structural organization of the phenylalanine-based nanostructures. An increase in the self-aggregation tendency was observed with longer PEG chains, whereas, independently of the PEG length, the peptide NSs display cross-β-like secondary structures with an antiparallel β-strand arrangement. WAXS/GIWAXS diffraction patterns indicate a progressive decrease in fiber order along the series. All the PEG-F6 derivatives present blue photoluminescent (PL) emission at 460 nm, with the adduct with the longest PEG chain (PEG₂₄ -F6) showing an additional green emission at 530 nm.