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Chronic hepatitis B infection remains a globally important cause of morbidity and mortality and has recently undergone a renaissance in therapeutic interest with increased pre-clinical and clinical testing of new drug classes. One of the first new classes in the clinic was RNA interference agents, which have the potential to impact the entire viral life cycle by reducing all virus-produced mRNA. Early clinical testing with the first of these agents in the clinic, ARC-520, demonstrated that rapid and deep reductions in viral proteins, RNA and DNA could be produced with this approach, but also the surprising insight that HBsAg production from incomplete HBV DNA integrated into the host genome appears to play a heretofore unappreciated and important role in maintaining circulating HBsAg, thought to play a fundamental role in preventing host clearance of the virus. Thus, accounting for viral DNA integration in novel HBV treatment approaches may prove to be essential to achieving successful finite therapies of this difficult to treat chronic infection.

Full-length hepatitis B virus (HBV) transcripts of chimpanzees and patients treated with multidose (MD) HBV siRNA ARC-520 and entecavir (ETV) were characterized by single-molecule real-time (SMRT) sequencing, identifying multiple types of transcripts with the potential to encode HBx, HBsAg, HBeAg, core, and polymerase, as well as transcripts likely to be derived from dimers of dslDNA, and these differed between HBeAg-positive (HBeAg+) and HBeAg-negative (HBeAg−) individuals. HBV transcripts from the last follow-up ~30 months post-ARC-520 treatment were categorized from one HBeAg+ (one of two previously highly viremic patients that became HBeAg− upon treatment and had greatly reduced cccDNA products) and four HBeAg− patients. The previously HBeAg+ patient received a biopsy that revealed that he had 3.4 copies/cell cccDNA (two to three orders of magnitude more cccDNA than HBeAg− chimpanzees) but expressed primarily truncated X and HBsAg from iDNA, like two patients that were HBeAg− at the start of the study and had one copy/cell cccDNA. No HBV transcripts were detected in two other HBeAg− patients that had ~0.3 copies/cell cccDNA, one of which had seroconverted for HBsAg. The paucity of cccDNA-derived transcripts in the presence of high cccDNA demonstrates the transcriptional silencing of HBV following MD siRNA treatment with ETV.

In a previous study, eight chronically HBV-infected nucleos (t)ide analog (NA)-naïve patients began receiving entecavir (ETV) concomitant with a single ARC-520 HBV siRNA injection. This single dose of ARC-520 (SD) was followed by 6–8 months of ETV alone before the patients received 4–9 monthly doses of ARC-520, the multi-dose (MD) period, while continuing ETV. Quantities of HBV DNA, RNA, and antigens were measured from serum and a liver biopsy collected ~30 months after the last MD from five patients. All full-length HBV transcripts from the livers were characterized. Viral parameters and HBV transcripts from patients were compared to these measurements collected at multiple points in ARC-520 + ETV-treated chronically HBV-infected chimpanzees. Multiple forms of HBx mRNA were observed, and these differed between chimpanzees and patients. Products of cccDNA were greatly decreased in patients who were previously highly viremic and HBeAg+, although a biopsied patient had similar amounts of cccDNA to the highly viremic HBeAg+ chimpanzees. The comparison of all HBV transcripts and cccDNA levels between patients and chimpanzees demonstrate the transcriptional silencing of cccDNA following the siRNA treatment of patients but not the chimpanzees that received a different treatment regimen. Results from this small study suggest that continued NA treatment during and between periods of HBV antigen re-expression post-siRNA treatment enhanced viral parameter reductions.

Severe AAT deficiency is caused by a mutation in SERPINA1 , which encodes AAT. Mutant AAT protein accumulates in the liver and can lead to liver disease. This phase 2 trial of an agent targeting SERPINA1 messenger RNA showed a reduction in levels of mutant AAT protein in affected persons.

ObjectiveWe examined the serological, virological (in serum and liver) and histological profiles in chronic hepatitis B virus (HBV) patients during and after completion of multiple dose (MD) ARC-520.DesignThe present phase 1b study was a multidose, open-label extension cohort of patients that had received single dose ARC-520 in our previous study. Eight patients received 4–9 4 weekly doses of MD ARC-520 and entecavir. Liver biopsies were performed in six patients. Intrahepatic and serum HBV DNA, HBV RNA and viral antigens were measured.ResultsAll patients had 28.9–30.4 months of follow-up after the last MD. All three hepatitis B e antigen (HBeAg)-positive patients had profound reductions in hepatitis B surface antigen (HBsAg), HBeAg, hepatitis B core-related antigen and HBV RNA with two undergoing HBeAg seroconversion. One further achieved HBsAg seroconversion (anti-HBs level of 25.1 IU/L) and the remaining two had HBsAg reductions of −1.7 and −3.5 log IU/mL >30 months after MD. Among the five HBeAg-negative patients, four had modest HBsAg reduction >29 months after completion of MD and one achieved HBsAg seroconversion (anti-HBs level of 152.5 IU/L) and was negative for liver HBsAg staining. Entecavir was successfully stopped in this patient 12 months after HBsAg seroconversion. Temporally related alanine aminotransferase elevations preceded by HBsAg reductions were observed in three patients suggesting immune activation. HBcAg staining was negative in all six biopsied patients. Two patients with <10% HBsAg positive staining of hepatocytes had correspondingly low serum HBsAg levels of 1.5 and 11.5 IU/mL.ConclusionsMD ARC-520 therapy achieved sustained and profound reductions of viral antigens and HBV RNA. HBsAg seroclearance was achievable.Trial registration number NCT02065336.

Alpha -antitrypsin (AAT) deficiency results from carriage of a homozygous \"Z\" mutation (proteinase inhibitor [PI] ZZ). The Z allele produces a mutant AAT protein called Z-AAT, which accumulates in hepatocytes and can lead to progressive liver disease and fibrosis. This open-label, phase 2 trial investigated the safety and efficacy of fazirsiran, an RNA interference therapeutic, in patients with liver disease associated with AAT deficiency. We assigned adults with the PI ZZ genotype and liver fibrosis to receive fazirsiran at a dose of 200 mg (cohorts 1 [4 patients] and 2 [8 patients]) or 100 mg (cohort 1b [4 patients]) subcutaneously on day 1 and week 4 and then every 12 weeks. The primary end point was the change from baseline to week 24 (cohorts 1 and 1b) or week 48 (cohort 2) in liver Z-AAT concentrations, which were measured by means of liquid chromatography-mass spectrometry. All the patients had reduced accumulation of Z-AAT in the liver (median reduction, 83% at week 24 or 48). The nadir in serum was a reduction of approximately 90%, and treatment was also associated with a reduction in histologic globule burden (from a mean score of 7.4 [scores range from 0 to 9, with higher scores indicating a greater globule burden] at baseline to 2.3 at week 24 or 48). All cohorts had reductions in liver enzyme concentrations. Fibrosis regression was observed in 7 of 15 patients and fibrosis progression in 2 of 15 patients after 24 or 48 weeks. There were no adverse events leading to trial or drug discontinuation. Four serious adverse events (viral myocarditis, diverticulitis, dyspnea, and vestibular neuronitis) resolved. In this small trial, fazirsiran was associated with a strong reduction of Z-AAT concentrations in the serum and liver and concurrent improvements in liver enzyme concentrations. (Funded by Arrowhead Pharmaceuticals; AROAAT-2002 ClinicalTrials.gov number, NCT03946449.).

The autosomal codominant genetic disorder alpha-1 antitrypsin (AAT) deficiency (AATD) causes pulmonary and liver disease. Individuals homozygous for the mutant Z allele accumulate polymers of Z-AAT protein in hepatocytes, where AAT is primarily produced. This accumulation causes endoplasmic reticulum (ER) stress, oxidative stress, damage to mitochondria, and inflammation, leading to fibrosis, cirrhosis, and hepatocellular carcinoma. The magnitude of AAT reduction and duration of response from first-generation intravenously administered RNA interference (RNAi) therapeutic ARC-AAT and then with next-generation subcutaneously administered ARO-AAT were assessed by measuring AAT protein in serum of the PiZ transgenic mouse model and human volunteers. The impact of Z-AAT reduction by RNAi on liver disease phenotypes was evaluated in PiZ mice by measuring polymeric Z-AAT in the liver; expression of genes associated with fibrosis, autophagy, apoptosis, and redox regulation; inflammation; Z-AAT globule parameters; and tumor formation. Ultrastructure of the ER, mitochondria, and autophagosomes in hepatocytes was evaluated by electron microscopy. In mice, sustained RNAi treatment reduced hepatic Z-AAT polymer, restored ER and mitochondrial health, normalized expression of disease-associated genes, reduced inflammation, and prevented tumor formation. RNAi therapy holds promise for the treatment of patients with AATD-associated liver disease. ARO-AAT is currently in phase II/III clinical trials.

To determine whether non-insulin-dependent diabetes is associated with specific alterations in the pattern of insulin secretion, we studied 16 patients with untreated diabetes and 14 matched controls. The rates of insulin secretion were calculated from measurements of peripheral C-peptide in blood samples taken at 15- to 20-minute intervals during a 24-hour period in which the subjects ate three mixed meals. Incremental responses of insulin secretion to meals were significantly lower in the diabetic patients (P<0.005), and the increases and decreases in insulin secretion after meals were more sluggish. These disruptions in secretory response were more marked after dinner than after break-fast, and a clear secretory response to dinner often could not be identified. Both the control and diabetic subjects secreted insulin in a series of discrete pulses. In the controls, a total of seven to eight pulses were identified in the period from 9 a.m. to 11 p.m., including the three post-meal periods (an average frequency of one pulse per 105 to 120 minutes), and two to four pulses were identified in the remaining 10 hours. The number of pulses in the patients and controls did not differ significantly. However, in the patients, the pulses after meals had a smaller amplitude (P<0.03) and were less frequently concomitant with a glucose pulse (54.7±4.9 vs. 82.2±5.0, P<0.001). Pulses also appeared less regularly in the patients. During glucose clamping to produce hyperglycemia (glucose level, 16.7 mmol per liter [300 mg per deciliter]), the diabetic subjects secreted, on the average, 70 percent less insulin than matched controls (P<0.001). These data suggest that profound alterations in the amount and temporal organization of stimulated insulin secretion may be important in the pathophysiology of beta-cell dysfunction in diabetes. (N Engl J Med 1988; 318:1231–9.) THE contribution of abnormal insulin secretion, as compared with resistance to insulin action, to the pathogenesis of non-insulin-dependent diabetes has been controversial. We investigated whether noninsulin-dependent diabetes is associated with specific alterations in the temporal pattern of insulin secretion. The 24-hour pattern of insulin secretion was defined in a group of patients with non-insulindependent diabetes and compared with that in a group of matched controls without diabetes. Standard techniques for evaluating beta-cell secretory function in human subjects involve the measurement of peripheral concentrations of insulin and C-peptide. These techniques do not provide quantitative estimates of insulin secretion because insulin undergoes . . .

A 51-year-old, nonobese man with diabetes mellitus had marked hyperinsulinemia (70 to 120 μU per milliliter; 502 to 860 pmol per liter) and fasting hyperglycemia (140 to 170 mg per 100 ml; 7.8 to 9.4 mmol per liter). Plasma proinsulin, glucagon, growth hormone, and cortisol levels were normal; insulin antibodies and insulin-receptor antibodies were not detected. The patient showed relatively normal insulin sensitivity, and insulin receptors on circulating monocytes were within the normal range. Insulin from the patient's serum bound to IM-9 lymphocytes and rat adipocytes approximately 40 per cent as well as insulin standards. Its biologic activity on rat adipocytes averaged 15 per cent of that expected from its immunologic concentration. The impaired biologic activity of this patient's circulating insulin was probably due to a structural abnormality. Subsequent studies of the patient's insulin (fortuitously obtained from his pancreas during a laparotomy for a pancreatic cyst) have confirmed this conclusion. (N Engl J Med 302:129–135, 1980) THE possibility that some patients with diabetes synthesize a structurally abnormal insulin molecule with reduced biologic activity has been considered for many years. 1 2 3 4 In 1966, Elliott et al. 5 showed that the circulating insulin in patients with juvenile-onset diabetes was relatively resistant to degradation by a proteolytic enzyme, insulinase, that was isolated from rat skeletal muscle. These authors suggested that an alteration in the structure of insulin in diabetics was responsible for this resistance to insulinase. 5 Kimmel and Pollock 6 analyzed the amino acid composition of insulins isolated from the pancreases of 11 non-diabetics and eight diabetics. Analysis of one sample from . . .

We have studied a 2-year-old girl with acanthosis nigricans, glucose intolerance, marked hyperinsulinemia, and somatic features characteristic of the leprechaunism syndrome. Circulating plasma insulin levels were increased up to 50-fold and the patient showed a blunted hypoglycemic response to an injection of exogenous insulin (0.2 units/kg), indicating the presence of severe insulin resistance. Insulin purified from the patient's plasma was normal on the basis of chromatographic, electrophoretic, and immunologic criteria. Furthermore, the purified insulin competed effectively with125I-labeled insulin for binding to insulin receptors on cultured IM-9 lymphocytes and rat fat cells and also exhibited normal biological potency when tested on rat fat cells. Anti-insulin receptor and anti-insulin antibodies were not detected in the patient's plasma, and plasma levels of glucagon, growth hormone, and cortisol were normal. Insulin binding to the patient's circulating mononuclear leukocytes was only slightly depressed into the low normal range and could not account for the severe insulin resistance. Studies on the patient's fibroblasts revealed normal levels of insulin receptors but a total absence of insulin's ability to accelerate glucose transport. Because rates of glucose transport and metabolism were normal in the basal state in the absence of insulin, we conclude that this patient's insulin resistance is due to an inherited cellular defect in the coupling mechanism between occupied insulin receptors and the plasma membrane glucose transport system.