Terlipressin and the Treatment of Hepatorenal Syndrome: How the CONFIRM Trial Moves the Story Forward

Long-Circulating Vasoactive 1,18-Octadecanedioic Acid-Terlipressin Conjugate

Hepatorenal syndrome (HRS) is a life-threatening complication of end-stage liver disease first reported over a century ago, but its management still poses an unmet challenge. A therapeutic agent found to stabilize the condition is a short cyclic peptide, vasopressin analogue, terlipressin (TP). While TP is commonly prescribed for HRS patients in most parts of the world, it was only recently approved for use in the United States. TP exhibits short circulation half-lives and adverse side effects associated with the dose required. Herein, we present a 1,18-octadecanedioic acid (ODDA) conjugate of the cyclic peptide (ODDA-TP), which enables noncovalent binding to serum albumin via native fatty acid binding modes. ODDA-TP is demonstrated to outperform TP alone in studies including in vitro cellular receptor activation, stability in plasma, pharmacokinetics, and performance in vivo in rats. Specifically, ODDA-TP had an elimination half-life 20 times that of TP alone while exhibiting a superior safety profile.

Terlipressin for hepatorenal syndrome

PURPOSE OF REVIEW

The definition and diagnostic criteria of hepatorenal syndrome-acute kidney injury (HRS-AKI) has undergone recent changes. A major vasoconstrictor, terlipressin, has recently been approved as pharmacotherapy for HRS-AKI in the United States. The purpose of this review is to familiarize the readers with these new diagnostic criteria of HRS-AKI, and how best to use terlipressin.

RECENT FINDINGS

Terlipressin is effective either as bolus dosing or continuous infusion and can achieve reversal of HRS-AKI in approximately 40% of patients. Continuous infusion allows lower daily dose with equal efficacy and less side effects but not an approved mode of administration in the United States. Response to terlipressin in the randomized controlled trials was defined as repeat reduction of serum creatinine to less than 1.5 mg/dl. Newer studies will likely require response to treatment to be defined as a repeat serum creatinine to be less than 0.3 mg/dl from baseline. Terlipressin use is associated with ischemic side effects and potential for respiratory failure development.

SUMMARY

Careful patient selection and close monitoring are necessary for its use. Response to terlipressin with HRS-AKI reversal is associated with improved outcomes with better survival and less requirement for renal replacement therapy.

Review article: Recent advances in ascites and acute kidney injury management in cirrhosis

BACKGROUND

Better understanding of disease pathophysiology has led to advances in managing ascites and its associated complications including hepatorenal syndrome-acute kidney Injury (HRS-AKI), especially medicinal and interventional advances.

AIM

To review the latest changes in the management of ascites and HRS-AKI.

METHODS

A literature search was conducted in Pubmed, using the keywords cirrhosis, ascites, renal dysfunction, acute kidney injury, hepatorenal syndrome, beta-blockers, albumin, TIPS and vasoconstrictors, including only publications in English.

RESULTS

The medicinal advances include earlier treatment of clinically significant portal hypertension to delay the onset of ascites and the use of human albumin solution to attenuate systemic inflammation thus improving the haemodynamic changes associated with cirrhosis. Furthermore, new classes of drugs such as sodium glucose co-transporter 2 are being investigated for use in patients with cirrhosis and ascites. For HRS-AKI management, newer pharmacological agents such as vasopressin partial agonists and relaxin are being studied. Interventional advances include the refinement of TIPS technique and patient selection to improve outcomes in patients with refractory ascites. The development of the alfa pump system and the study of outcomes associated with the use of long-term palliative abdominal drain will also serve to improve the quality of life in patients with refractory ascites.

CONCLUSIONS

New treatment strategies emerged from better understanding of the pathophysiology of ascites and HRS-AKI have shown improved prognosis in these patients. The future will see many of these approaches confirmed in large multi-centre clinical trials with the aim to benefit the patients with ascites and HRS-AKI.

Hepatorenal Syndrome Type 1: Diagnosis and Treatment

Hepatorenal syndrome (HRS) is a feared complication in patients with advanced cirrhosis and is associated with significant morbidity and mortality. While recognized as a distinct physiologic condition for well over one hundred years, a lack of objective diagnostic tests has made the diagnosis one of exclusion. Since 1979, multiple sets of diagnostic criteria have been proposed. Though varying in detail, the principal intent of these criteria is to identify patients with severe, functional acute kidney injury that is unresponsive to volume resuscitation and exclude those with structural injury. However, accurate differential diagnosis remains challenging. Recently, multiple urinary biomarkers of kidney injury, including neutrophil gelatinase-associated lipocalin, have been studied as a means of objectively phenotyping etiologies of acute kidney injury in patients with cirrhosis. Along with markers reflecting tubular functional integrity, including the fractional excretion of sodium, injury markers will likely be incorporated into future diagnostic criteria. Making an accurate diagnosis is critical, as therapeutic options exist for HRS but must be given in a timely manner and only to those patients likely to benefit. Terlipressin, an analog of vasopressin, is the first line of therapy for HRS in much of the world and has recently been approved for use in the United States. Significant questions remain regarding the optimal dosing strategy, metrics for titration, and the potential role of point-of-care ultrasound to help guide concurrent albumin administration.

Securing the diagnosis of HRS-AKI: implications for current therapies

INTRODUCTION

Hepatorenal syndrome (HRS)-acute kidney injury (HRS-AKI) is a specific type of kidney injury seen in patients with cirrhosis and ascites and is associated with high mortality and morbidity. It is characterized by rapid deterioration of renal function due to reduced renal blood flow secondary to portal hypertensive splanchnic and systemic vasodilation. Early diagnosis and treatment of HRS-AKI are associated with greater likelihood of improvement in renal function, lower need for dialysis, and better post-transplant outcomes.

AREAS COVERED

This review discusses the diagnostic criteria for HRS-AKI, which has undergone several key changes over the last decade, with an aim to secure an early diagnosis and aid swift treatment initiation. Additionally, this review outlines the current treatment paradigms for HRS-AKI.

EXPERT OPINION

In the last 20 years, there have been several advances in understanding the pathophysiology and natural course of HRS-AKI. These have led to critical changes in its definition and diagnostic algorithm. However, prognosis of HRS-AKI remains dismal with no significant improvement in HRS-AKI reversal or HRS-related mortality over this time. We discuss several gaps in the current understanding and management of HRS-AKI that will benefit from further research.

Incidence and outcomes of acute kidney injury including hepatorenal syndrome in hospitalized patients with cirrhosis in the US

BACKGROUND & AIMS

Acute kidney injury (AKI) in cirrhosis is common and associated with high morbidity, but the incidence rates of different etiologies of AKI are not well described in the US. We compared incidence rates, practice patterns, and outcomes across etiologies of AKI in cirrhosis.

METHODS

We performed a retrospective cohort study of 11 hospital networks, including consecutive adult patients admitted with AKI and cirrhosis in 2019. The etiology of AKI was adjudicated based on pre-specified clinical definitions (prerenal/hypovolemic AKI, hepatorenal syndrome [HRS-AKI], acute tubular necrosis [ATN], other).

RESULTS

A total of 2,063 patients were included (median age 62 [IQR 54-69] years, 38.3% female, median MELD-Na score 26 [19-31]). The most common etiology was prerenal AKI (44.3%), followed by ATN (30.4%) and HRS-AKI (12.1%); 6.0% had other AKI, and 7.2% could not be classified. In our cohort, 8.1% of patients received a liver transplant and 36.5% died by 90 days. The lowest rate of death was observed in patients with prerenal AKI (22.2%; p <0.001), while death rates were higher but not significantly different from each other in those with HRS-AKI and ATN (49.0% vs. 52.7%; p = 0.42). Using prerenal AKI as a reference, the adjusted subdistribution hazard ratio (sHR) for 90-day mortality was higher for HRS-AKI (sHR 2.78; 95% CI 2.18-3.54; p <0.001) and ATN (sHR 2.83; 95% CI 2.36-3.41; p <0.001). In adjusted analysis, higher AKI stage and lack of complete response to treatment were associated with an increased risk of 90-day mortality (p <0.001 for all).

CONCLUSION

AKI is a severe complication of cirrhosis. HRS-AKI is uncommon and is associated with similar outcomes to ATN. The etiology of AKI, AKI stage/severity, and non-response to treatment were associated with mortality. Further optimization of vasoconstrictors for HRS-AKI and supportive therapies for ATN are needed.

IMPACT AND IMPLICATIONS

Acute kidney injury (AKI) in cirrhosis carries high morbidity, and management is determined by the etiology of injury. However, a large and well-adjudicated multicenter database from US centers that uses updated AKI definitions is lacking. Our findings demonstrate that acute tubular necrosis and hepatorenal syndrome have similar outcomes (∼50% mortality at 90 days), though hepatorenal syndrome is uncommon (12% of all AKI cases). These findings represent practice patterns at US transplant/tertiary centers and can be used as a baseline, presenting the situation prior to the adoption of terlipressin in the US.

INFUSE: Rationale and design of a multi-center, open label, collaborative study to treat HRS-AKI with continuous terlipressin infusion

Background

Hepatorenal syndrome-acute kidney injury (HRS-AKI) carries significant morbidity and mortality among those with end-stage liver disease. Bolus terlipressin for treatment of HRS-AKI received FDA approval in September 2022. US implementation of terlipressin, however, is hindered by the paucity of local data on the optimal patient population and administration mode, as well as the effect on transplant priority. The INFUSE study is designed to evaluate the use of continuous terlipressin infusion among transplant candidates with advanced liver disease and HRS-AKI.

Methods

Fifty prospective patients with HRS-AKI will receive a single bolus of terlipressin 0.5 mg followed by continuous infusions of terlipressin from 2 to 8 mg/day for up to 14 days. The cohort will be enriched with those listed, in evaluation, or eligible for liver transplantation, while those with ACLF grade 3, MELD ≥35, and serum creatinine >5.0 mg/dL will be excluded. Fifty patients who received midodrine plus octreotide or norepinephrine for HRS-AKI will serve as a retrospective comparator cohort.

Conclusion

The INFUSE study aims to assess the safety and efficacy of continuous terlipressin infusion among largely transplant-eligible patients with HRS-AKI, and to provide US-based data on transplant outcomes. This novel study design simultaneously mitigates terlipressin adverse events while providing renal benefits to patients, thus addressing the unmet medical need of those with HRS-AKI who have limited treatment options and are awaiting liver transplantation in the US.

New drug approvals for 2022: Synthesis and clinical applications

The U.S. Food and Drug Administration has approved a total of 37 new drugs in 2022, which are composed of 20 chemical entities and 17 biologics. In particular, 20 chemical entities, including 17 small molecule drugs, 1 radiotherapy, and 2 diagnostic agents, provide privileged scaffolds, breakthrough clinical benefits, and a new mechanism of action for the discovery of more potent clinical candidates. The structure-based drug development with clear targets and fragment-based drug development with privileged scaffolds have always been the important modules in the field of drug discovery, which could easily bypass the patent protection and bring about improved biological activity. Therefore, we summarized the relevant valuable information about clinical application, mechanism of action, and chemical synthesis of 17 newly approved small molecule drugs in 2022. We hope this timely and comprehensive review could bring about creative and elegant inspiration on the synthetic methodologies and mechanism of action for the discovery of new drugs with novel chemical scaffolds and extended clinical indications.

Beyond conventional physical examination in hepatology: POCUS

Point-of-care ultrasound (POCUS) refers to the use of ultrasound imaging through pocket-sized sonographic devices at the patient's bedside, to make a diagnosis or direct a procedure and immediately answer a clinical question. Its goal is to broaden the physical examination, not to replace conventional ultrasound studies. POCUS has evolved as a complement to physical examination and has been adopted by different medical specialties, including hepatology. A narrative synthesis of the evidence on the applications of POCUS in hepatology was carried out, describing its usefulness in the diagnosis of cirrhosis of the liver, metabolic dysfunction-associated steatotic liver disease (MASLD), decompensated cirrhosis, and portal hypertension. The review also encompasses more recent applications in the hemodynamic evaluation of the critically ill patient with cirrhosis of the liver, patients with other liver diseases, as well as in the ultrasound guidance of procedures. POCUS could make up part of the daily clinical practice of gastroenterologists and hepatologists, simplifying the initial evaluation of patients and optimizing clinical management. Its accessibility, ease of use, and low adverse event profile make POCUS a useful tool for the properly trained physician in the adequate clinical setting. The aim of this review was to describe the available evidence on the usefulness of POCUS in the daily clinical practice of gastroenterologists and hepatologists.

Effect of different infusion approaches on safety and efficacy of terlipressin: Current controversies

Terlipressin, a synthetic analog of vasopressin, has been widely used to treat acute variceal bleeding, hepatorenal syndrome, and other complications of cirrhosis. However, among different infusion approaches of terlipressin, its safety and efficacy are also heterogeneous. Previous studies have demonstrated that continuous infusion of terlipressin is more effective with a lower incidence of adverse events than intermittent intravenous infusion. This paper aims to review the relevant literature and summarize the data regarding the safety and effectiveness of different infusion approaches of terlipressin to guide clinical practice.

Terlipressin in the management of liver disease

INTRODUCTION

Terlipressin is a synthetic vasopressin analog which has been recently approved in the United States by the Food and Drug Administration for the treatment of hepatorenal syndrome. Terlipressin stimulates vasopressin receptors located on the smooth muscle vasculature of the splanchnic circulation and renal tubules which results in splanchnic vasoconstriction with improved renal perfusion and antidiuretic activity, respectively.

AREAS COVERED

In this review, we discuss available data regarding the FDA approved use of terlipressin, safety, and tolerability, as well as highlight alternative uses in chronic liver disease currently still under investigation.

EXPERT OPINION

Terlipressin is more efficacious compared to other vasoactive agents including midodrine octreotide and norepinephrine in reversal of hepatorenal syndrome and improves short-term survival. Other potential applications of terlipressin's vasoconstrictor actions reported in the literature include management of variceal hemorrhage and other complications of portal hypertension.

Hepatorenal Syndrome: Pathophysiology, Diagnosis, and Treatment

Hepatorenal syndrome (HRS) is a primarily functional form of acute kidney injury (AKI) that develops in patients with decompensated cirrhosis. The pathophysiologic cascade that leads to HRS begins with pooling of blood in the splanchnic system, resulting in a decrease in effective circulating arterial volume. The definitive treatment of HRS is liver transplantation. When this is not possible, HRS is treated with a combination of vasoconstrictor agents and intravenous albumin. Although the combination of midodrine and octreotide is used in the United States, the recently approved terlipressin, an analog of vasopressin, is likely to become the first-line standard of care.

A Systematic Review of the Emerging Treatment for Hepatorenal Syndrome With a Principal Focus on Terlipressin: A Recent FDA-Approved Drug

BACKGROUND

 Hepatorenal syndrome (HRS), a consequence of liver cirrhosis, is the development of renal failure, which carries a grave prognosis. Reversing acute renal failure with various vasoconstrictor therapies at an appropriate time favors a good prognosis, especially when a liver transplant is not feasible.

OBJECTIVE

 This study aims to compare various treatment modalities to deduce an effective way to manage HRS.

METHODS

 The authors conducted a literature search in PubMed, Google Scholar, the Cochrane Library, and Science Direct in October 2022, using regular and MeSH keywords. A total of 1072 articles were identified. The PRISMA guidelines were used, the PICO framework was addressed, and the inclusion criteria were set based on studies from the past 10 years. After quality assessment, 14 studies were included for in-depth analysis in this review.  Results: A total of 14 studies were included after quality assessment, including randomized controlled trials, systematic reviews, meta-analyses, and observational cohort studies. Nine hundred and forty-one patients represented this review's experimental and observational studies, apart from the other systematic reviews analyzed. Nine studies discovered that Terlipressin, especially when administered with albumin, was more effective than other conventional treatment modalities, including norepinephrine and midodrine, in terms of improving mortality and reversing the HRS. Four studies suggested that terlipressin exhibited similar effectiveness but found no significant difference. In contrast, one study found that norepinephrine was superior to terlipressin when particularly considering the adverse effects.

CONCLUSION

 Terlipressin, one of the most widely used vasoconstrictor agents across the world, seems to be effective in reversing renal failure in HRS. Although adverse effects are seen with this agent, it is still beneficial when compared to other medications. Further studies with larger sample sizes may be warranted.

Role of Terlipressin in Patients With Hepatorenal Syndrome-Acute Kidney Injury Admitted to the ICU: A Substudy of the CONFIRM Trial

This study assessed the potential advantages of treating hepatorenal syndrome-acute kidney injury (HRS-AKI) with terlipressin versus placebo in the ICU setting.

DESIGN

Patients were randomly assigned in a 2:1 ratio to receive terlipressin or placebo for up to 14 days.

SETTING

A retrospective analysis of data from the phase III CONFIRM study.

PARTICIPANTS

Adult patients with HRS-AKI admitted to the ICU.

MAIN OUTCOMES AND MEASURES

In this substudy, we evaluated outcomes of the ICU stay and the need for organ support, including renal replacement therapy (RRT).

RESULTS

Among 300 patients with HRS-AKI from the CONFIRM study, 45 were treated in the ICU (terlipressin, 31/199 [16%]; placebo, 14/101 [14%]). On ICU admission, baseline demographics were similar across treatment arms, including severity of liver dysfunction. Among patients alive at the end of the ICU stay, those randomized to terlipressin had a significantly shorter median length of ICU stay than placebo (4 vs 11 d; p < 0.001). Terlipressin-treated patients had a significantly larger improvement in renal function from baseline versus placebo (-0.7 vs +0.2 mg/dL; p = 0.001), including when accounting for the interaction between treatment and day-of-patient-admission to the ICU (-0.7 vs +0.9 mg/dL; p < 0.001). Cumulative requirement for RRT through day 90 was improved in the terlipressin arm versus placebo (10/31 [32%] vs 8/14 [57%]; p = 0.12), although not significantly. Of 13 patients who received a liver transplant, five out of five (100%) in the placebo arm needed RRT through day 90 versus five out of eight (63%) in the terlipressin arm.

CONCLUSIONS

In this subanalysis of CONFIRM, patients admitted to the ICU with HRS-AKI who received terlipressin were more likely to achieve renal function improvement, based on serum creatinine changes by the end of treatment, and had significantly shorter lengths of ICU stay than patients randomized to the placebo arm.

Current Status of Peptide Medications and the Position of Active Therapeutic Peptides with Scorpion Venom Origin

: Peptides are highly potent, selective, and relatively safe therapeutics. Over the past two decades, natural peptides have been obtained, studied, and eventually approved by the Food and Drug Administration (FDA) due to advancements in identification, production, modification, and analytical technologies. Some peptide therapeutics has been derived from the venom gland of venomous animals, including snake, leech, lizard, snail, and scorpion. Scorpion was identified as a reservoir of important peptides with pharmaceutical properties. The scorpion uses these peptides for capturing prey and defense. However, their pharmacological properties in treating different diseases, including cardiac problems, autoimmune and infectious diseases, and diverse cancers, have been confirmed. Ion channel modifiers are the greatest components of the scorpion venom glands. Due to advances in proteomic and transcriptomic approaches, the identification of new scorpion venom peptides is steadily increasing. In this review, we tried to represent the current status of peptide medicines and describe the last peptide medications approved by FDA in 2022. Moreover, we will further explain potent peptides originating from scorpion venom, which have gone through important steps to be approved.

Renal Insufficiency in Patients with Cirrhosis

Renal failure is one of the most prevalent complications in patients with cirrhosis and is of the utmost prognostic relevance. Acute kidney injury (AKI) in cirrhosis results from a spectrum of etiologies, of which hepatorenal syndrome (HRS) carries the worst prognosis. Correct differentiation of the etiology of AKI in cirrhosis is imperative, as treatment defers substantially. This review summarizes the current diagnostic criteria, pathophysiology, diagnosis, and therapeutic concepts for AKI and HRS-AKI in cirrhosis.