Odevixibat: First Approval

Peptide therapeutics: current status and future opportunity with focus on nose-to-brain delivery☆

Peptide drugs are a highly diverse group of therapeutic agents. Over the last decade, more than 40 peptides have been approved for clinical use. They target different structures, ranging from G protein-coupled receptors (GPCRs) to pathogens and are used to treat a variety of indications, including metabolic disorders, genetic diseases, acute illnesses and more. Structurally, peptide therapeutics are a heterogeneous class. This diversity allows them to bridge the gap between small molecules and biologics. However, limited metabolic stability and bioavailability must be addressed. Strategies to improve the half-life include backbone and sequence modification, cyclization and the addition of stabilizing moieties. Great strides have been made in recent years towards achieving sufficient drug uptake for oral application have been achieved within recent years. However, these methods require specialized peptide design or involve permeabilization of the gastrointestinal tract. Consequently, other routes of administration are being explored. One promising approach is the nasal application of peptides. This method can be used for systemic uptake, but also allows for direct nose-to-brain delivery of compounds. While successful nose-to-brain delivery is already used in the clinic, the underlining mechanisms are poorly understood. Strategies for rational optimization are needed to make this method more applicable to a wider range of compounds. Overall, approved peptide therapeutics cover a wide range of applications and have demonstrated a growing and novel potential in recent drug discovery.

Odevixibat therapy in progressive familial intrahepatic cholestasis with MYO5B variants: a retrospective case series

BACKGROUND AND RATIONALE

Progressive familial intrahepatic cholestasis (PFIC) associated with myosin 5B deficiency is a rare liver disease characterised by elevated serum bile acids (sBAs) and severe pruritus. The objective of this study was to evaluate treatment with the ileal bile acid transporter inhibitor odevixibat in affected children.

METHODS

This was a retrospective analysis of five children with a diagnosis of PFIC associated with myosin 5B deficiency and pruritus refractory to treatment with rifampicin and ursodeoxycholic acid, starting odevixibat treatment (37.2-120 µg/kg.day) between 15 months and 10 years of age. Clinical and laboratory data were collected regularly, including liver biochemistry and treatment history. Pruritus and sleep disorders were rated on a four-point Likert scale (absent, mild, moderate or severe).

RESULTS

In the year before starting odevixibat, all patients presented with moderate to severe refractory pruritus. Four patients had sleep disturbances. One patient had a history of microvillus inclusion disease and was parenterally fed during his first year of life. In the year prior to initiating odevixibat, sBA levels were > 150 µmol/L and total bilirubin levels were > 25 µmol/L in all patients. Within six months after starting odevixibat, sBA levels normalised to < 10 µmol/L and total bilirubin fell to < 15 µmol/L. Bilirubin and sBA levels remained mostly normal throughout the treatment period (from 22 to 39 months) in four patients. Pruritus and sleep disturbances improved in the first three months and disappeared completely on treatment in four patients. In two patients, compliance and access to treatment were limited, which may explain the fluctuations in treatment response. In one patient, odevixibat treatment was discontinued following an episode of infectious gastroenteritis leading to a rise in sBA and symptom recurrence which did not respond to treatment reinitiation. Digestive tolerability of odevixibat was good; no new or worsening gastrointestinal symptoms were observed in any child.

CONCLUSION

This case series indicates that treatment with odevixibat is effective in children with myosin 5B-related PFIC and encourages further research into the utility of this medication in rare forms of PFIC.

Hepatic Expression of Fibroblast Growth Factor 19 Significantly Correlates With Serum Bile Acids in Neonatal Cholestasis

BACKGROUND

Bile acids in the ileum act as a feedback regulator of their own synthesis by inducing the release of ileal fibroblast growth factor 19 (FGF19), which inhibits the cholesterol-7-alpha hydroxylase enzyme. In cholestasis, this feedback mechanism is dysregulated. FGF19 is not expressed in the healthy liver. We aimed to assess the hepatic expression of FGF19 in neonatal cholestasis (NC) and its relation to serum bile acids.

METHODS

The study included 41 patients with NC. FGF19 immunohistochemical staining in liver tissue (hepatocytes, endothelial cells, bile ducts, and bile canaliculi) was evaluated as negative, weak, moderate, and strong staining. FGF19 staining in 6 liver samples from explants of children with Crigler-Najjar syndrome type-1 served as controls.

RESULTS

Hepatocyte, endothelial, and canalicular FGF19 expression was significantly higher in cholestasis group compared to controls (P = .039, .006, and .028 respectively). Serum bile acids had significant correlation with hepatocyte FGF19, endothelial, and bile duct FGF19 expressions (P = .002, .003, and .01, respectively) but not with canalicular FGF19 expression. Hepatocyte FGF19 expression significantly associated with cholestasis severity in terms of serum total bilirubin, direct bilirubin, and aspartate transaminase levels (P = .01, .02, and .02, respectively).

CONCLUSION

Hepatic FGF19 expression significantly upregulated in NC and correlated with cholestasis severity.

Real-world experience with odevixibat in children with progressive familial intrahepatic cholestasis

Background & aims

A previously published trial demonstrated that odevixibat is effective in the treatment of cholestatic pruritus of children with progressive familial intrahepatic cholestasis (PFIC). Real-world experience is necessary to confirm the results of registration trials with selective eligibility criteria. We present our 'real-life experience' of the effectiveness and safety of odevixibat in patients with different PFIC subtypes.

Methods

We carried out a multicenter prospective study of patients with PFIC treated with odevixibat (40 or escalated to 120 μg/kg/day). Pruritus was assessed by 'Physician Global Impression of Symptom' at baseline and monthly up to 6 months. Serum bile acids (sBA) responders were patients who achieved a reduction in sBA levels ≥70% from baseline (or a value <70 μmol/L) after 6 months; pruritus responders were patients who reported improvement in their pruritus score.

Results

In total, 24 patients (median age 6.6 years [3.7-12.1], male:female = 11/13) were enrolled; 16 (67%) had classic PFIC types (PFIC-1, 2; PFIC-2, 11; and PFIC-3, 3), whereas eight (33%) had rarer forms (PFIC-4, 5, PFIC-5, 1; PFIC-6, 1; and PFIC-9, 1). All had high sBA levels and 22/24 (92%) had pruritus. Four (17%) had associated comorbidities.After 6 months of treatment, sBA decreased from a median of 317.1 μmol/L (range 82.3-369.0 μmol/L) to 45.6 μmol/L (range 7.2-120 μmol/L; p <0.001); the mean change in pruritus score was -1.7. Overall, 75% of patients were sBA responders, 73% were pruritus responders, and 30% required dose escalation. Reduced pruritus correlated significantly with reduced sBA (p <0.05). A cut-off value of sBA >333.5 μmol/L increased the risk of no response to odevixibat by 17-fold (p <0.001). No serious adverse events were recorded.

Conclusions

Odevixibat is effective and safe in reducing sBA levels and improving pruritus in a real-life scenario in both patients with classic PFIC types and in those with other rarer subtypes. Dose escalation is required in some patients to improve the response to treatment.

Impact and implications

Published data on the use of odevixibat in a real-world scenario are lacking. We explored the effectiveness of odevixibat in a heterogenous cohort of children diagnosed with PFIC (including patients with classic as well as rarer types of PFIC, and with advanced liver disease and associated comorbidities). Our results demonstrate that odevixibat is effective for the treatment of cholestasis and pruritus in children with different PFIC subtypes in a real-life scenario. These results support the use of odevixibat in children with any type of PFICs, including those with different stages of liver disease and comorbidities.

The Potential of Peptide-Based Inhibitors in Disrupting Protein-Protein Interactions for Targeted Cancer Therapy

Protein-protein interactions (PPIs) form an intricate cellular network known as the interactome, which is essential for various cellular processes, such as gene regulation, signal transduction, and metabolic pathways. The dysregulation of this network has been closely linked to various disease states. In cancer, these aberrant PPIs, termed oncogenic PPIs (OncoPPIs), are involved in tumour formation and proliferation. Therefore, the inhibition of OncoPPIs becomes a strategy for targeted cancer therapy. Small molecule inhibitors have been the dominant strategy for PPI inhibition owing to their small size and ability to cross cell membranes. However, peptide-based inhibitors have emerged as compelling alternatives, offering distinct advantages over small molecule inhibitors. Peptides, with their larger size and flexible backbones, can effectively engage with the broad interfaces of PPIs. Their high specificity, lower toxicity, and ease of modification make them promising candidates for targeted cancer therapy. Over the past decade, significant advancements have been made in developing peptide-based inhibitors. This review discusses the critical aspects of targeting PPIs, emphasizes the significance of OncoPPIs in cancer therapy, and explores the advantages of using peptide-based inhibitors as therapeutic agents. It also highlights recent progress in peptide design aimed at overcoming the limitations of peptide therapeutics, offering a comprehensive overview of the current landscape and potential of peptide-based inhibitors in cancer treatment.

Exploring bile acid transporters as key players in cancer development and treatment: Evidence from preclinical and clinical studies

Bile acid transporters (BATs) are integral membrane proteins belonging to various families, such as solute carriers, organic anion transporters, and ATP-binding cassette families. These transporters play a crucial role in bile acid transportation within the portal and systemic circulations, with expression observed in tissues, including the liver, kidney, and small intestine. Bile acids serve as signaling molecules facilitating the absorption and reabsorption of fats and lipids. Dysregulation of bile acid concentration has been implicated in tumorigenesis, yet the role of BATs in this process remains underexplored. Emerging evidence suggests that BATs may modulate various stages of cancer progression, including initiation, development, proliferation, metastasis, and tumor microenvironment regulation. Targeting BATs using siRNAs, miRNAs, and small compound inhibitors in preclinical models and their polymorphisms are well-studied for transporters like BSEP, MDR1, MRP2, OATP1A2, etc., and have shed light on their involvement in tumorigenesis, particularly in cancers such as those affecting the liver and gastrointestinal tract. While BATs' role in diseases like Alagille syndrome, biliary atresia, and cirrhosis have been extensively studied, their implications in cancer warrant further investigation. This review highlights the expression and function of BATs in cancer development and emphasizes the potential of targeting these transporters as a novel therapeutic strategy for various malignancies.

Emerging drugs for the treatment of progressive familial intrahepatic cholestasis: a focus on phase II and III trials

INTRODUCTION

Progressive familial intrahepatic cholestasis (PFIC) is a group of disorders characterized by inappropriate bile formation, causing hepatic accumulation of bile acids and, subsequently, liver injury. Until recently, no approved treatments were available for these patients.

AREAS COVERED

Recent clinical trials for PFIC treatment have focused on intestine-restricted ileal bile acid transporter (IBAT) inhibitors. These compounds aim to reduce the pool size of bile acids by interrupting their enterohepatic circulation. Other emerging treatments in the pipeline include systemic IBAT inhibitors, synthetic bile acid derivatives, compounds targeting bile acid synthesis via the FXR/FGF axis, and chaperones/potentiators that aim to enhance the residual activity of the mutated transporters.

EXPERT OPINION

Substantial progress has been made in drug development for PFIC patients during the last couple of years. Although data concerning long-term efficacy are as yet only scarcely available, new therapies have demonstrated robust efficacy in a considerable fraction of patients at least on the shorter term. However, a substantial fraction of PFIC patients do not respond to these novel therapies and thus still requires surgical treatment, including liver transplantation before adulthood. Hence, there is still an unmet medical need for long-term effective medical, preferably non-surgical, treatment for all PFIC patients.

Odevixibat as an adjunctive treatment for refractory pruritus in rare variants of cholestatic liver disease

Objectives

Odevixibat, a reversible ileal bile acid transport inhibitor, has been shown to reduce serum bile acids (sBA) and pruritus mostly in children with progressive familial intrahepatic cholestasis (PFIC) 1 and 2 in clinical trials and case reports. There are currently no published case reports or series describing its use in rare variants of cholestatic liver disease.

Methods

We describe three children with progressive cholestatic liver disease who developed refractory pruritus, who had a genotypic diagnosis of AKR1D1, ABCB4 variant, and PKHD1 and PKHD2 variants; all being variants of unknown significance as per the American College of Medical Genetics and Genomics guidelines.

Results

On Odevixibat there was a significant improvement in sBA (absolute change from baseline: -196 and -393 μmol/L) and pruritus in two children with heterozygous AKR1D1 and ABCB4 mutations. The child with ABCB4 variants was found to have features of sclerosing cholangitis along with a diagnosis of Crohn's disease, which represents the first reported usage of Odevixibat in such a case with good response. There was some reported improvement in the third child with PKHD1 and PKHD2 variants; however, we hypothesize that no sustained improvement could be due to severe and progressive nature of the disease. There were no side effects reported and it was well tolerated in all.

Conclusion

We suggest that Odevixibat may be used as an adjunctive drug in refractory pruritus and could be started early in the course of disease if clinically and phenotypically indicated.

Transporter Proteins as Therapeutic Drug Targets-With a Focus on SGLT2 Inhibitors

Membrane transporters interact not only with endogenous substrates but are also engaged in the transport of xenobiotics, including drugs. While the coordinated function of uptake (solute carrier family-SLC and SLCO) and efflux (ATP-binding cassette family-ABC, multidrug and toxic compound extrusion family-MATE) transporter system allows vectorial drug transport, efflux carriers alone achieve barrier functions. The modulation of transport functions was proved to be effective in the treatment strategies of various pathological states. Sodium-glucose cotransporter-2 (SGLT2) inhibitors are the drugs most widely applied in clinical practice, especially in the treatment of diabetes mellitus and heart failure. Sodium taurocholate co-transporting polypeptide (NTCP) serves as virus particles (HBV/HDV) carrier, and inhibition of its function is applied in the treatment of hepatitis B and hepatitis D by myrcludex B. Inherited cholestatic diseases, such as Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC) can be treated by odevixibat and maralixibat, which inhibit activity of apical sodium-dependent bile salt transporter (ASBT). Probenecid can be considered to increase uric acid excretion in the urine mainly via the inhibition of urate transporter 1 (URAT1), and due to pharmacokinetic interactions involving organic anion transporters 1 and 3 (OAT1 and OAT3), it modifies renal excretion of penicillins or ciprofloxacin as well as nephrotoxicity of cidofovir. This review discusses clinically approved drugs that affect membrane/drug transporter function.

Sodium/bile acid co-transporter inhibitors currently in preclinical or early clinical development for the treatment of primary biliary cholangitis

INTRODUCTION

Pruritus is common and often undertreated in patients with primary biliary cholangitis (PBC). Existing treatments largely have an aging and low-quality evidence base, and studies included only small numbers of patients. More recent data that has added to our understanding of pruritus treatments has often come from clinical trials where itching was a secondary outcome measure in a trial designed primarily to assess disease-modifying agents. This area represents an unmet clinical need in the management of PBC.

AREAS COVERED

In this manuscript, we first summarize the proposed mechanisms for PBC-related pruritus and the current treatment paradigm. We then present an appraisal of the existing pre-clinical and clinical evidence for the use of ileal bile acid transporter inhibitors (IBATis) for this indication in PBC patients.

EXPERT OPINION

Evidence for the efficacy of IBATis is promising but limited by the currently available volume of data. Furthermore, larger clinical trials with long-term data on efficacy, safety and tolerability are needed to confirm the role of using IBATis in clinical practice and their place on the itch treatment ladder. Additional focus should also be given to exploring the disease-modifying potential of IBATis in PBC.

Impact of Drug-Mediated Inhibition of Intestinal Transporters on Nutrient and Endogenous Substrate Disposition…an Afterthought?

A large percentage (~60%) of prescription drugs and new molecular entities are designed for oral delivery, which requires passage through a semi-impervious membrane bilayer in the gastrointestinal wall. Passage through this bilayer can be dependent on membrane transporters that regulate the absorption of nutrients or endogenous substrates. Several investigations have provided links between nutrient, endogenous substrate, or drug absorption and the activity of certain membrane transporters. This knowledge has been key in the development of new therapeutics that can alleviate various symptoms of select diseases, such as cholestasis and diabetes. Despite this progress, recent studies revealed potential clinical dangers of unintended altered nutrient or endogenous substrate disposition due to the drug-mediated disruption of intestinal transport activity. This review outlines reports of glucose, folate, thiamine, lactate, and bile acid (re)absorption changes and consequent adverse events as examples. Finally, the need to comprehensively expand research on intestinal transporter-mediated drug interactions to avoid the unwanted disruption of homeostasis and diminish therapeutic adverse events is highlighted.

Odevixibat: A Novel Bile Salt Inhibitor Treatment for Pruritus in Progressive Familial Intrahepatic Cholestasis

Chronic pruritus is defined as an itch lasting greater than six weeks. It can manifest from a wide variety of etiologies, as many different substances can act as pruritogens, such as steroids, histamine, progesterone, endogenous opioids, and serotonin. In the setting of cholestatic liver disease, increased bile acids play a major role in chronic pruritus. The itching in cholestatic liver disease is worsened in intensity at night and localized frequently to the palms, soles, knees, and other pressure sites. It can be hard to manage, affecting the quality of sleep and causing irritability, poor attention, and, in some cases, depression. One such disease that results from chronic pruritus is progressive familial intrahepatic cholestasis (PFIC), a group of uncommon hereditary disorders that affects the formation of bile and its outflow from the liver. Previously, the drug ursodeoxycholic acid was used to help manage pruritus or surgical procedures, e.g., partial external biliary diversion or partial internal biliary diversion, to help control complications of the disease. This literature review will discuss three clinical studies covering the effectiveness of odevixibat in treating pruritus in patients with PFIC. Odevixibat (Bylvay) is an oral drug that has been FDA-approved to treat pruritus in patients three months of age and older with PFIC. Odevixibat prevents the reabsorption of bile salts in the intestines, resulting in decreased levels of bile salts via their excretion in stool. Several studies have determined that the drug is well tolerated and provides a nonsurgical, pharmacological treatment alternative for those with PFIC.

Opinion paper on the diagnosis and treatment of progressive familial intrahepatic cholestasis

Background & Aims

Progressive familial intrahepatic cholestasis (PFIC) relates to a group of rare, debilitating, liver disorders which typically present in early childhood, but have also been reported in adults. Without early detection and effective treatment, PFIC can result in end-stage liver disease. The aim of the paper was to put forward recommendations that promote standardisation of the management of PFIC in clinical practice.

Methods

A committee of six specialists came together to discuss the challenges faced by physicians in the management of PFIC. The committee agreed on two key areas where expert guidance is required to optimise care: (1) how to diagnose and treat patients with a clinical presentation of PFIC in the absence of clear genetic test results/whilst awaiting results, and (2) how to monitor disease progression and response to treatment. A systematic literature review was undertaken to contextualise and inform the recommendations.

Results

An algorithm was developed for the diagnosis and treatment of children with suspected PFIC. The algorithm recommends the use of licensed inhibitors of ileal bile acid transporters as the first-line treatment for patients with PFIC and suggests that genetic testing be used to confirm genotype whilst treatment is initiated in patients in whom PFIC is suspected. The authors recommend referring patients to an experienced centre, and ensuring that monitoring includes measurements of pruritus, serum bile acid levels, growth, and quality of life following diagnosis and during treatment.

Conclusions

The algorithm presented within this paper offers guidance to optimise the management of paediatric PFIC. The authors hope that these recommendations will help to standardise the management of PFIC in the absence of clear clinical guidelines.

Impact and implications

This opinion paper outlines a consistent approach to the contemporaneous diagnosis, monitoring, referral and management of children with progressive familial intrahepatic cholestasis. This should assist physicians given the recent developments in genetic diagnosis and the availability of effective drug therapy. This manuscript will also help to raise awareness of current developments and educate health planners on the place for new drug therapies in progressive familial intrahepatic cholestasis.

Loss of SLC27A5 Activates Hepatic Stellate Cells and Promotes Liver Fibrosis via Unconjugated Cholic Acid

Although the dysregulation of bile acid (BA) composition has been associated with fibrosis progression, its precise roles in liver fibrosis is poorly understood. This study demonstrates that solute carrier family 27 member 5 (SLC27A5), an enzyme involved in BAs metabolism, is substantially downregulated in the liver tissues of patients with cirrhosis and fibrosis mouse models. The downregulation of SLC27A5 depends on RUNX family transcription factor 2 (RUNX2), which serves as a transcriptional repressor. The findings reveal that experimental SLC27A5 knockout (Slc27a5-/- ) mice display spontaneous liver fibrosis after 24 months. The loss of SLC27A5 aggravates liver fibrosis induced by carbon tetrachloride (CCI4 ) and thioacetamide (TAA). Mechanistically, SLC27A5 deficiency results in the accumulation of unconjugated BA, particularly cholic acid (CA), in the liver. This accumulation leads to the activation of hepatic stellate cells (HSCs) by upregulated expression of early growth response protein 3 (EGR3). The re-expression of hepatic SLC27A5 by an adeno-associated virus or the reduction of CA levels in the liver using A4250, an apical sodium-dependent bile acid transporter (ASBT) inhibitor, ameliorates liver fibrosis in Slc27a5-/- mice. In conclusion, SLC27A5 deficiency in mice drives hepatic fibrosis through CA-induced activation of HSCs, highlighting its significant implications for liver fibrosis treatment.

Combined inhibition of bile salt synthesis and intestinal uptake reduces cholestatic liver damage and colonic bile salts in mice

BACKGROUND & AIMS

Intestine-restricted inhibitors of the apical sodium-dependent bile acid transporter (ASBT, or ileal bile acid transporter) are approved as treatment for several inheritable forms of cholestasis but are also associated with abdominal complaints and diarrhoea. Furthermore, blocking ASBT as a single therapeutic approach may be less effective in moderate to severe cholestasis. We hypothesised that interventions that lower hepatic bile salt synthesis in addition to intestinal bile salt uptake inhibition provide added therapeutic benefit in the treatment of cholestatic disorders. Here, we test combination therapies of intestinal ASBT inhibition together with obeticholic acid (OCA), cilofexor, and the non-tumorigenic fibroblast growth factor 15 (Fgf15)/fibroblast growth factor 19 (FGF19) analogue aldafermin in a mouse model of cholestasis.

METHODS

Wild-type male C57Bl6J/OlaHsd mice were fed a 0.05% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet and received daily oral gavage with 10 mg/kg OCA, 30 mg/kg cilofexor, 10 mg/kg ASBT inhibitor (Linerixibat; ASBTi), or a combination. Alternatively, wild-type male C57Bl6J/OlaHsd mice were injected with adeno-associated virus vector serotype 8 (AAV8) to express aldafermin, to repress bile salt synthesis, or to control AAV8. During a 3-week 0.05% DDC diet, mice received daily oral gavage with 10 mg/kg ASBTi or placebo control.

RESULTS

Combination therapy of OCA, cilofexor, or aldafermin with ASBTi effectively reduced faecal bile salt excretion. Compared with ASBTi monotherapy, aldafermin + ASBTi further lowered plasma bile salt levels. Cilofexor + ASBTi and aldafermin + ASBTi treatment reduced plasma alanine transaminase and aspartate transaminase levels and fibrotic liver immunohistochemistry stainings. The reduction in inflammation and fibrogenesis in mice treated with cilofexor + ASBTi or aldafermin + ASBTi was confirmed by gene expression analysis.

CONCLUSIONS

Combining pharmacological intestinal bile salt uptake inhibition with repression of bile salt synthesis may form an effective treatment strategy to reduce liver injury while dampening the ASBTi-induced colonic bile salt load.

IMPACT AND IMPLICATIONS

Combined treatment of intestinal ASBT inhibition with repression of bile salt synthesis by farnesoid X receptor agonism (using either obeticholic acid or cilofexor) or by expression of aldafermin ameliorates liver damage in cholestatic mice. In addition, compared with ASBT inhibitor monotherapy, combination treatments lower colonic bile salt load.

Diagnosis and management of Alagille and progressive familial intrahepatic cholestasis

Alagille syndrome and progressive familial intrahepatic cholestasis are conditions that can affect multiple organs. Advancements in molecular testing have aided in the diagnosis of both. The impairment of normal bile flow and secretion leads to the various hepatic manifestations of these diseases. Medical management of Alagille syndrome and progressive familial intrahepatic cholestasis remains mostly targeted on supportive care focusing on quality of life, cholestasis, and fat-soluble vitamin deficiency. The most difficult therapeutic issue is typically related to pruritus, which can be managed by various medications such as ursodeoxycholic acid, rifampin, cholestyramine, and antihistamines. Surgical operations were previously used to disrupt enterohepatic recirculation, but recent medical advancements in the use of ileal bile acid transport inhibitors have shown great efficacy for the treatment of pruritus in both Alagille syndrome and progressive familial intrahepatic cholestasis.

Fresh Baked: An Overview of Newly FDA-Approved Drugs for Dermatological Usage

With our better understanding of the pathogenesis of various diseases, more and more drugs and biological products are being tried and tested every day. Roughly, around 40-50 novel drugs get approved by the Food and Drug Administration (FDA) for use in the general population, making it difficult for a physician to keep track of the constant changes in therapy. This article aimed to provide a compilation of all the FDA-approved new drugs for dermatological conditions and new dermatological indications of known drugs in the recent past, especially for dermatology residents and practising dermatologists. A comprehensive analysis, based on the list of new molecular entities approved by the FDA from 2020 to 2023, as well as a thorough English language literature search from 2020 to July 2023 across multiple databases (PubMed, MEDLINE, Springer Nature, Google Scholar and Cochrane) for various keywords (alone and in combination) such as "FDA approved" OR "recent advances in therapy" OR "recent drugs" OR "novel treatment" OR "dermatology," was performed. All data extracted were incorporated into the present compilation. A total of 33 drugs, including newly approved and newly approved indications of previously known drugs, were found. Relevant information about them has been discussed in a tabulated manner. This article provides an at a glance summarised profile of the newly FDA-approved drugs, as available in the existing literature. However, with the astonishing rate of new drugs hitting the market, more and more clinical trials are required to ensure the rational use of these agents.

Treatment with an ileal bile acid transporter inhibitor in patients with TJP2 deficiency

There are no published data on the use of odevixibat, a selective ileal bile acid transporter (IBAT) inhibitor, in children with tight junction protein 2 (TJP2) deficiency (also named as PFIC-4). We describe a case series of five children treated with odevixibat. After treatment, serum bile acids (sBA) decreased compared to baseline [mean value: 244 (±125), vs 38 (±34) µmol/L; p = 0.007]; reduction in sBA was >70% from baseline (or <70 µmol/L) in all. Improvements in pruritus were reported in all patients. The drug was well tolerated. IBAT inhibitors should be considered a valuable treatment option in patients with TJP2 deficiency.

The molecular insights of bile acid homeostasis in host diseases

Bile acids (BAs) function as detergents promoting nutrient absorption and as hormones regulating nutrient metabolism. Most BAs are key regulatory factors of physiological activities, which are involved in the regulation of glucose, lipid, and drug metabolisms. Hepatic and intestinal diseases have close connections with the systemic cycling disorders of BAs. The abnormal in BA absorption came up with overmuch BAs could be involved in the pathophysiology of liver and bowel and metabolic disorders such as fatty liver diseases and inflammatory bowel diseases. The primary BAs (PBAs), which are synthesized in the liver, can be transformed into the secondary BAs (SBAs) by gut microbiota. The transformation processes are tightly associated with the gut microbiome and the host endogenous metabolism. The BA biosynthesis gene cluster bile-acid-inducible operon is essential for modulating BA pool, gut microbiome composition, and the onset of intestinal inflammation. This forms a bidirectional interaction between the host and its gut symbiotic ecosystem. The subtle changes in the composition and abundance of BAs perturb the host physiological and metabolic activity. Therefore, maintaining the homeostasis of BAs pool contributes to the balance of the body's physiological and metabolic system. Our review aims to dissect the molecular mechanisms underlying the BAs homeostasis, assess the key factors sustaining the homeostasis and the role of BA acting on host diseases. By linking the BAs metabolic disorders and their associated diseases, we illustrate the effects of BAs homeostasis on health and potential clinical interventions can be taken under the latest research findings.

Synthetic Approaches to the New Drugs Approved During 2021

Each year, new drugs are introduced to the market, representing structures that have affinity for biological targets implicated in human diseases and conditions. These new chemical entities (NCEs), particularly small molecules and antibody-drug conjugates, provide insight into molecular recognition and serve as potential leads for the design of future medicines. This annual review is part of a continuing series highlighting the most likely process-scale synthetic approaches to 35 NCEs that were first approved anywhere in the world during 2021.

Progressive Familial Intrahepatic Cholestasis: A Descriptive Study in a Tertiary Care Center

Background

Progressive familial intrahepatic cholestasis (PFIC) is a rare genetic disorder that results from defective mechanisms of bile secretion. We aim to describe different types of PFIC and their clinical features, treatment modalities, and outcomes in Saudi Arabia. Patients and Methods. This is a retrospective study of all patients diagnosed with PFIC at King Faisal Specialist Hospital and Research Center in Riyadh from January 1, 2002, to December 31, 2021. All relevant information was collected from patient charts and transferred into the REDcap® database for statistical analysis.

Results

A total of 79 patients were identified with PFIC, and PFIC type 3 was the most common (59.5%), followed by PFIC type 2 (34.2%), PFIC type 1 (5.1%), and PFIC type 4 (1.3%). Males and females were affected in 54.4% and 45.6%, respectively. Mutations in ATP8B1, ABCB11, and ABCB4 genes were observed in PFIC type 1, PFIC type 2, and PFIC type 3, and loss of function in a variant of TJP2 was detected in PFIC type 4, respectively. A total of 51 (64.6%) patients underwent liver transplantation: three patients (3/4) with PFIC type 1 (75%), twenty patients (20/27) with PFIC type 2 (74.1%), twenty-seven patients (27/47) with PFIC type 3 (57.4%), and one patient with PFIC type 4 (100%). The mean duration of disease before transplantation was 53.9 ± 67 months with a median of 30 months. Following liver transplantation, symptomatic control was achieved in 47 patients (92.2%). Recurrence after transplantation occurred in 4 patients (7.8%) within an average of 22.5 months and a median of 17 months.

Conclusion

PFIC is considered a rare disorder in Saudi Arabia; however, early recognition of the disease is important for appropriate management and early referral for liver transplantation evaluation. The overall rate of liver transplantation in our cohort was 64.6% with an excellent five-year survival rate.

Current Therapies for Cholestatic Diseases

Cholestasis is a condition characterized by decrease in bile flow due to progressive pathological states that lead to chronic cholestatic liver diseases which affect the biliary tree at the intrahepatic level and extrahepatic level. They induce complications such as cirrhosis, liver failure, malignancies, bone disease and nutritional deficiencies that merit close follow-up and specific interventions. Furthermore, as those conditions progress to liver cirrhosis, there will be an increase in mortality but also an important impact in quality of life and economic burden due to comorbidities related with liver failure. Therefore, it is important that clinicians understand the treatment options for cholestatic liver diseases. With a general view of therapeutic options and their molecular targets, this review addresses the pathophysiology of cholangiopathies. The objective is to provide clinicians with an overview of the safety and efficacy of the treatment of cholangiopathies based on the current evidence.

Primary biliary cholangitis: Epidemiology, prognosis, and treatment

Primary biliary cholangitis (PBC) is a chronic cholestatic autoimmune liver disease characterized by a destructive, small duct, and lymphocytic cholangitis, and marked by the presence of antimitochondrial antibodies. The incidence and prevalence of PBC vary widely in different regions and time periods, and although disproportionally more common among White non-Hispanic females, contemporary data show a higher prevalence in males and racial minorities than previously described. Outcomes largely depend on early recognition of the disease and prompt institution of treatment, which, in turn, are directly influenced by provider bias and socioeconomic factors. Ursodeoxycholic acid remains the initial treatment of choice for PBC, with obeticholic acid and fibrates (off-label therapy) reserved as add-on therapy for the management of inadequate responders or those with ursodeoxycholic acid intolerance. Novel and repurposed drugs are currently at different stages of clinical development not only for the treatment of PBC but also for its symptomatic management. Here, we summarize the most up-to-date data regarding the epidemiology, prognosis, and treatment of PBC, providing clinically useful information for its holistic management.

Trust Your Gut: Strategies and Tactics for Intestinally Restricted Drugs

Non-absorbable small-molecule drugs targeted to the gut represent an alternative approach to safe, non-systemic therapeutics. Such drugs remain confined to the gastrointestinal tract upon oral dosing by virtue of their limited passive permeability, increasing the local concentration at the site of action while minimizing exposure elsewhere in the body. Herein we review the latest advances in the field of gut-restricted therapeutics, highlighting the different strategies and tactics that medicinal chemists have employed in pursuit of drugs with minimal intestinal absorption.

Case Report: Add-on treatment with odevixibat in a new subtype of progressive familial intrahepatic cholestasis broadens the therapeutic horizon of genetic cholestasis

Odevixibat, an ileal bile acid transporter (IBAT) inhibitor, is effective for the treatment of pruritus in children diagnosed with progressive familial intrahepatic cholestasis (PFIC) type 1 and 2. There are no studies showing the efficacy of Odevixibat in children with different subtypes of PFIC. We describe the case of a 6-year-old girl with chronic cholestatic jaundice. In the last 12 months laboratory data showed high serum levels of bilirubin (total bilirubin x 2.5 ULN; direct bilirubin x 1.7 ULN) and bile acids (sBA x 70 ULN), elevated transaminases (x 3-4 ULN), and preserved synthetic liver function. Genetic testing showed homozygous mutation in ZFYVE19 gene, which is not included among the classic causative genes of PFIC and determined a new non-syndromic phenotype recently classified as PFIC9 (OMIM # 619849). Due to the persistent intensity of itching [score of 5 (very severe) at the Caregiver Global Impression of Severity (CaGIS)] and sleep disturbances not responsive to rifampicin and ursodeoxycholic acid (UDCA), Odevixibat treatment was started. After treatment with odevixibat we observed: (i) reduction in sBA from 458 to 71 μmol/L (absolute change from baseline: -387 μmol/L), (ii) reduction in CaGIS from 5 to 1, and (iii) resolution of sleep disturbances. The BMI z-score progressively increased from -0.98 to +0.56 after 3 months of treatment. No adverse drug events were recorded. Treatment with IBAT inhibitor was effective and safe in our patient suggesting that Odevixibat may be potentially considered for the treatment of cholestatic pruritus also in children with rare subtypes of PFIC. Further studies on a larger scale could lead to the increasing of patients eligible for this treatment.

Internal Ileal Diversion as Treatment for Progressive Familial Intrahepatic Cholestasis Type 1-Associated Graft Inflammation and Steatosis after Liver Transplantation

BACKGROUND

Progressive Familial Intrahepatic cholestasis type I (PFIC1) is a rare congenital hepatopathy causing cholestasis with progressive liver disease. Surgical interruption of the enterohepatic circulation, e.g., surgical biliary diversion (SBD) can slow down development of liver cirrhosis. Eventually, end stage liver disease necessitates liver transplantation (LT). PFIC1 patients might develop diarrhea, graft steatosis and inflammation after LT. SBD after LT was shown to be effective in the alleviation of liver steatosis and graft injury.

CASE REPORT

Three PFIC1 patients received LT at the ages of two, two and a half and five years. Shortly after LT diarrhea and graft steatosis was recognized, SBD to the terminal ileum was opted to prevent risk for ascending cholangitis. After SBD, inflammation and steatosis was found to be reduced to resolved, as seen by liver biochemistry and ultrasounds. Diarrhea was reported unchanged.

CONCLUSION

We present three PFIC1 cases for whom SBD to the terminal ileum successfully helped to resolve graft inflammation and steatosis.

Surgical and Medical Aspects of the Initial Treatment of Biliary Atresia: Position Paper

Biliary atresia, a fibro-obliterative disease of the newborn, is usually initially treated by Kasai portoenterostomy, although there are many variations in technique and different options for post-operative adjuvant medical therapy. A questionnaire on such topics (e.g., open vs. laparoscopic; the need for liver mobilisation; use of post-operative steroids; use of post-operative anti-viral therapy, etc.) was circulated to delegates (n = 43) of an international webinar (Biliary Atresia and Related Diseases-BARD) held in June 2021. Respondents were mostly European, but included some from North America, and represented 18 different countries overall. The results of this survey are presented here, together with a commentary and review from an expert panel convened for the meeting on current trends in practice.

Odevixibat: a promising new treatment for progressive familial intrahepatic cholestasis

INTRODUCTION

Progressive familial intrahepatic cholestasis (PFIC) refers to a group of heterogeneous, mostly autosomal recessive disorders resulting from the inability to properly form and excrete bile from hepatocytes. The resulting shared phenotype is one of hepatocellular cholestasis. Clinical management targeting refractory itch and surgical interventions to interrupt the enterohepatic circulation are often pursued with variable efficacy. Recent development of the family of IBAT inhibitor therapeutics has introduced a novel tool in the armamentarium for the treatment of PFIC.

AREAS COVERED

Data from Phase 3 and 3 clinical trials were reviewed. The primary endpoints in most studies included effect on pruritus, serum bile acid levels, and quality of life metrics, with the duration of the study ranging between 24 and 72 weeks. Most common adverse events included diarrhea, vomiting, and elevation in transaminases.

EXPERT OPINION

IBAT inhibition with therapeutics such as odevibixat have shown that it is well-tolerated and efficacious in mitigating itch and reducing serum bile acid levels. While the few early published trials with odevixibat have shown good efficacy, what remains to be seen is long-term, sustainable improvement and if or how these medications will supplement or replace the current medical and surgical therapies available for managing PFIC disorders.

Evaluation and Management of Pruritus in Primary Biliary Cholangitis

Chronic pruritus is a classic symptom in patients with primary biliary cholangitis. It affects up to two-thirds of patients in the course of the disease. Efficient therapy consists of topical treatment combined with systemic options such as anion exchangers, rifampicin, bezafibrate, μ-opioid receptor antagonists, selective-serotonin receptor uptake inhibitors, and gabapentinoids. Future therapeutic approaches may contain the selective blockade of the enterohepatic cycle by inhibiting the ileal bile acid transporter, the agonism at κ-opioid receptors, and antagonism of the mas-related G protein-coupled receptor X4. As nondrug treatment, ultraviolet B therapy, albumin dialysis, and biliary drainage are available at specialized centers.

Case Report: Novel JAG1 gene mutations in two infants with alagille syndrome characterized by cholestasis

Background

Infants with Alagille syndrome (ALGS) need to be promptly differentiated from biliary atresia (BA) at an early stage. ALGS is an autosomal, dominant, multisystem disorder with variable phenotypic penetrance caused by heterozygous mutations in JAG1 or NOTCH2, which encode the Notch signaling pathway.

Case presentation

We report two cases, both with cholestatic jaundice as the main manifestation, in which BA was excluded and finally diagnosed as ALGS based on characteristic facial features, serological tests, imaging, laparoscopic cholangiography, pathology and genetic findings. Both cases are novel mutant genes on chromosome 20 that have not been reported in the literature. The mutation in patient 1 was a novel heterozygous nonsense mutation (NM_000214 exon20, c.2419G > T, p.E807Ter), which was a spontaneous mutation. Followed up to 1 year and 6 months, the symptoms resolved with ursodeoxycholic acid and cholestyramine, and the jaundice has now subsided. Patient 2 was a novel heterozygous frameshift mutation (NM_000214 exon19, c.2367-2368dupTC, p.P790Lfs*31), which was inherited from his mother. This patient was followed up to 9 months and is currently awaiting liver transplantation.

Conclusion

Both cholestatic infants reported combined to exclude BA, avoid Kasai portoenterostomy (KPE), and definitively diagnose ALGS. Broadening the spectrum of JAG1 gene mutations.

Update on the Pharmacological Treatment of Primary Biliary Cholangitis

Ursodeoxycholic acid (UDCA) is the first-line therapy used for the treatment of PBC. In recent years, new pharmacological agents have been proposed for PBC therapy to cure UDCA-non-responders. Obeticholic acid (OCA) is registered in many countries for PBC, and fibrates also seem to be effective in ameliorating biochemistry alteration and symptoms typical of PBC. Moreover, a variety of new agents, acting with different mechanisms of action, are under clinical evaluation for PBC treatment, including PPAR agonists, anti-NOX agents, immunomodulators, and mesenchymal stem cell transplantation. Since an insufficient amount of data is currently available about the effect of these novel approaches on robust clinical endpoints, such as transplant-free survival, their clinical approval needs to be supported by the consistent improvement of these parameters. The intensive research in this field will hopefully lead to a novel treatment landscape for PBC in the near future, with innovative therapies based on the combination of multiple agents acting on different pathogenetic mechanisms.

The Latest FDA-Approved Pharmaceuticals Containing Fragments of Tailor-Made Amino Acids and Fluorine

Nowadays, the selective introduction of fluorine into bioactive compounds is a mature strategy in the design of drugs allowing to increase efficiency, biological half-life and bio-absorption. On the other hand, amino acids (AAs) represent one of the most ubiquitious classes of naturally occurring organic compounds, which are found in over 40% of newly marked small-molecule pharmaceutical drugs and medical formulations. The primary goal of this work is to underscore two major trends in the design of modern pharmaceuticals. The first is dealing with the unique structural characteristics provided by the structure of amino acids featuring an abundance of functionality and the presence of a stereogenic center, all of which bodes well for the successful development of targeted bioactivity. The second is related to fine-tuning the desired activity and pharmacokinetics by selective introduction of fluorine. Historically, both trends were developed separately as innovative and prolific approaches in modern drug design. However, in recent decades, these approaches are clearly converging leading to an ever-increasing number of newly approved pharmaceuticals containing both structural features of amino acids and fluorine.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2021

The second year of the COVID-19 pandemic had no adverse effect on the number of new drug approvals by the US Food and Drug Administration (FDA). Quite the contrary, with a total of 50 new drugs, 2021 belongs to the most successful FDA years. We assign these new drugs to one of three levels of innovation: (1) first drug against a condition ("first-in-indication"), (2) first drug using a novel molecular mechanism ("first-in-class"), and (3) "next-in-class", i.e., a drug using an already exploited molecular mechanism. We identify 21 first-in-class, 28 next-in-class, and only one first-in-indication drugs. By treatment area, the largest group is once again cancer drugs, many of which target specific genetic alterations. Every second drug approved in 2021 targets an orphan disease, half of them being cancers. Small molecules continue to dominate new drug approvals, followed by antibodies and non-antibody biopharmaceuticals. In 2021, the FDA continued to approve drugs without strong evidence of clinical effects, best exemplified by the aducanumab controversy.

Targeting bile acid signaling for the treatment of liver diseases: From bench to bed

Liver diseases and related complications have become one of the leading causes of morbidity and mortality worldwide, yet effective medicine or approved treatment approach is still limited. Thus, novel therapy is urgently required to prevent or at least slow down the growing burden of liver transplantation or even death caused by malignant liver diseases. As the irreplaceable modulator of hepatic and intestinal signaling cascades, bile acids (BAs) play complex physiological as well as pathological roles in regulating energy and immune homeostasis in various liver diseases, including but not limited to metabolic diseases and cholangiopathies, making them highly attractive therapeutic targets. In the current review, recent progress in the research of enterohepatic circulation of BAs and potential therapeutic targets of BAs signaling, especially the development of currently available treatments, including agonizts of FXR and TGR5, analogs of FGF19, inhibitors of ASBT, and the regulation of gut microbiome through fecal microbiota transplantation were extensively summarized. Their protective effects, molecular mechanisms, and outcomes of clinical trials were highlighted. The structural features of these candidates and perspectives for their future development were further discussed. In conclusion, we believe that pharmacological therapies targeting BAs signaling represent promising and efficient strategies for the treatment of complex and multifactorial liver disorders.

Cholestatic Itch: Our Current Understanding of Pathophysiology and Treatments

Hepatic pruritus is common in liver conditions, including cholestasis and nonalcoholic fatty liver disease. The pruritus can be severe enough to diminish sleep and decrease quality of life. The pathophysiology likely involves many molecules and receptors, including bile acids, bilirubin, lysophosphatidic acid (LPA), endogenous opioids, and serotonin. Recent advances suggest a significant role of Mas-related G protein-coupled receptor X4 (MRGPRX4) and autotaxin/LPA as key players in cholestatic pruritus. Further research is needed to develop increasingly targeted therapies with greater efficacy, especially given that many patients report itch refractory to various treatments. Cholestyramine was the only US FDA-approved drug for cholestatic pruritus until recent approval of ileal bile acid transporter (IBAT) inhibitors for use in the pediatric cholestatic conditions, progressive familial intrahepatic cholestasis and Alagille syndrome. Both medications decrease the bile acid pool. IBAT inhibitors are under investigation for broader use, and targeting LPA receptors and MRGPR4 are additional attractive options.

Genetics in Familial Intrahepatic Cholestasis: Clinical Patterns and Development of Liver and Biliary Cancers: A Review of the Literature

The family of inherited intrahepatic cholestasis includes autosomal recessive cholestatic rare diseases of childhood involved in bile acids secretion or bile transport defects. Specific genetic pathways potentially cause many otherwise unexplained cholestasis or hepatobiliary tumours in a healthy liver. Lately, next-generation sequencing and whole-exome sequencing have improved the diagnostic procedures of familial intrahepatic cholestasis (FIC), as well as the discovery of several genes responsible for FIC. Moreover, mutations in these genes, even in the heterozygous status, may be responsible for cryptogenic cholestasis in both young and adults. Mutations in FIC genes can influence serum and hepatic levels of bile acids. Experimental studies on the NR1H4 gene have shown that high bile acids concentrations cause excessive production of inflammatory cytokines, resistance to apoptosis, and increased cell regeneration, all risk conditions for developing hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). NR1H4 gene encodes farnesoid X-activated receptor having a pivotal role in bile salts synthesis. Moreover, HCC and CCA can emerge in patients with several FIC genes such as ABCB11, ABCB4 and TJP2. Herein, we reviewed the available data on FIC-related hepatobiliary cancers, reporting on genetics to the pathophysiology, the risk factors and the clinical presentation.

Gene Therapy for Acquired and Genetic Cholestasis

Cholestatic diseases can be caused by the dysfunction of transporters involved in hepatobiliary circulation. Although pharmacological treatments constitute the current standard of care for these diseases, none are curative, with liver transplantation being the only long-term solution for severe cholestasis, albeit with many disadvantages. Liver-directed gene therapy has shown promising results in clinical trials for genetic diseases, and it could constitute a potential new therapeutic approach for cholestatic diseases. Many preclinical gene therapy studies have shown positive results in animal models of both acquired and genetic cholestasis. The delivery of genes that reduce apoptosis or fibrosis or improve bile flow has shown therapeutic effects in rodents in which cholestasis was induced by drugs or bile duct ligation. Most studies targeting inherited cholestasis, such as progressive familial intrahepatic cholestasis (PFIC), have focused on supplementing a correct version of a mutated gene to the liver using viral or non-viral vectors in order to achieve expression of the therapeutic protein. These strategies have generated promising results in treating PFIC3 in mouse models of the disease. However, important challenges remain in translating this therapy to the clinic, as well as in developing gene therapy strategies for other types of acquired and genetic cholestasis.

Ileal Bile Acid Transporter Inhibition Reduces Post-Transplant Diarrhea and Growth Failure in FIC1 Disease—A Case Report

Familial intrahepatic cholestasis 1 (FIC1) disease is a genetic disorder characterized by hepatic and gastrointestinal disease due to ATP8B1 deficiency, often requiring liver transplantation (LT). Extrahepatic symptoms, such as diarrhea, malabsorption, and failure to thrive, do not improve and instead may be aggravated after LT. We describe a patient with FIC1 disease who underwent LT at 2 years, 8 months of age. After LT, the child developed severe refractory diarrhea and failed to thrive. The response to bile acid resins was unsatisfactory, and the parents declined our recommendation for partial external biliary diversion (PEBD). Quality of life was extremely impaired, especially due to severe diarrhea, making school attendance impossible. Attempting to reduce the total bile acids, we initiated off-label use of the ileal bile acid transporter (IBAT) inhibitor Elobixibat (Goofice^™), later converted to Odevixibat (Bylvay^™). After six months of treatment, the patient showed less stool output, increased weight and height, and improved physical energy levels. The child could now pursue higher undergraduate education. In our patient with FIC1 disease, the use of IBAT inhibitors was effective in treating chronic diarrhea and failure to thrive. This approach is novel; further investigations are needed to clarify the exact mode of action in this condition.

The importance of sulfur-containing motifs in drug design and discovery

INTRODUCTION

Sulfur-containing functional groups are privileged motifs that occur in various pharmacologically effective substances and several natural products. Various functionalities are found with a sulfur atom at diverse oxidation states, as illustrated by thioether, sulfoxide, sulfone, sulfonamide, sulfamate, and sulfamide functions. They are valuable scaffolds in the field of medicinal chemistry and are part of a large array of approved drugs and clinical candidates.

AREA COVERED

Herein, the authors review the current research on the development of organosulfur-based drug discovery. This article also covers details of their roles in the new lead compounds reported in the literature over the past five years 2017-2021.

EXPERT OPINION

Given its prominent role in medicinal chemistry and its importance in drug discovery, sulfur has attracted continuing interest and has been used in the design of various valuable compounds that demonstrate a variety of biological and pharmacological feature activities. Overall, sulfur's role in medicinal chemistry continues to grow. However, many sulfur functionalities remain underused in small-molecule drug discovery and deserve special attention in the armamentarium for treating diverse diseases. Research efforts are also still required for the development of a synthetic methodology for direct access to these functions and late-stage functionalization.

2021 FDA TIDES (Peptides and Oligonucleotides) Harvest

From the medical, pharmaceutical, and social perspectives, 2021 has been a year dominated by the COVID-19 pandemic. However, despite this global health crisis, the pharmaceutical industry has continued its endeavors, and 2021 could be considered an excellent year in terms of the drugs accepted by the US Food and Drug Administration (FDA). Thus, during this year, the FDA has approved 50 novel drugs, of which 36 are new chemical entities and 14 biologics. It has also authorized 10 TIDES (8 peptides, 2 oligonucleotides), in addition to 2 antibody-drug conjugates (ADCs) whose structures contain peptides. Thus, TIDES have accounted for about 24% of the approvals in the various drug categories. Importantly, this percentage has surpassed the figure in 2020 (10%), thus reflecting the remarkable success of TIDES. In this review, the approved TIDE-based drugs are analyzed on the basis of their chemical structure, medical target, mode of action, administration route, and adverse effects.

Biliary diversion in progressive familial intrahepatic cholestasis: a systematic review and meta-analysis

BACKGROUND

Biliary diversion (BD) is indicated in progressive familial intrahepatic cholestasis (PFIC) with refractory pruritus. Three types-partial external biliary drainage (PEBD), partial internal biliary drainage (PIBD), and ileal exclusion (IE) are described, with no consensus about the relative efficacy of these procedures.

METHODS

PubMed, Scopus, and Google Scholar were searched for publications on PFIC and BD. Improvement in pruritus, serum bile acid (BA), and need for liver transplantation (LT) were compared between the various BD procedures.

RESULTS

25 studies [424 children (PEBD-301, PIBD-93, IE-30)] were included. Pruritus resolved in 59.5% [PIBD:72% (95%CI 43-96%), PEBD:57% (95%CI 43-71%) and IE:48% (95%CI 14-82%)] cases. Significant overlap in confidence intervals indicated no significant differences. Absolute decrease in BA (AUROC-0.72) and bilirubin (AUROC-0.69) discriminated responders and non-responders. Eventually, 27% required LT: PIBD 10.7%, PEBD32%, IE 27%. The post-operative BA (AUROC-0.9) and bilirubin (AUROC-0.85) determined need for LT. Complications were commoner in PEBD than PIBD (38% vs 21.8%: p=0.02).

CONCLUSION

59.5% children have pruritus relief after BD and 27% need LT. PIBD has lower complications and LT requirement than PEBD. However, this requires cautious interpretation as the 2 groups differed in PFIC type and follow-up duration.