mRNA and gene editing: Late breaking therapies in liver diseases.

The efficient delivery of RNA molecules to restore the expression of a missing or inadequately functioning protein in a target cell and the intentional specific modification of the host genome using engineered nucleases represent therapeutic concepts that are revolutionizing modern medicine. The initiation of several clinical trials using these approaches to treat metabolic liver disorders as well as the recently reported remarkable results obtained by patients with transthyretin amyloidosis highlight the advances in this field and show the potential of these therapies to treat these diseases safely and efficaciously. These advances have been possible due, firstly, to significant improvements made in RNA chemistry that increase its stability and prevent activation of the innate immune response and, secondly, to the development of very efficient liver-targeted RNA delivery systems. In parallel, the breakout of CRISPR/CRISPR-associated 9-based technology in the gene editing field has marked a turning point in in vivo modification of the cellular genome with therapeutic purposes, which can be based on gene supplementation, correction, or silencing. In the coming years we are likely to witness the therapeutic potential of these two strategies both separately and in combination. In this review we summarize the preclinical data obtained in animal models treated with mRNA as a therapeutic agent and discuss the different gene editing strategies applied to the treatment of liver diseases, highlighting both their therapeutic efficacy as well as safety concerns.

The importance of frailty assessment in multiple myeloma: a position statement from the Myeloma Scientific Advisory Group to Myeloma Australia.

Multiple myeloma (MM) is a disease of older people, yet factors relating to comorbidity and frailty may threaten treatment tolerability for many of this heterogenous group. There has been increasing interest in defining specific and clinically relevant frailty assessment tools within the MM population, with the goal of using these frailty scores, not just as a prognostic instrument, but also as a predictive tool to allow for a frailty-adapted treatment approach. This paper reviews the various frailty assessment frameworks used in the evaluation of patients with MM, including the International Myeloma Working Group Frailty Index (IMWG-FI), the Mayo Frailty Index and the simplified frailty scale. While the IMWG-FI remains the most widely accepted tool, the simplified frailty scale is the most user-friendly in busy day-to-day clinics based on its ease of use. This paper summarises the recommendations from the Myeloma Scientific Advisory Group (MSAG) of Myeloma Australia, on the use of frailty assessment tools in clinical practice and proposes a frailty-stratified treatment algorithm to aid clinicians in tailoring therapy for this highly heterogeneous patient population.

Use of an adeno-associated virus serotype Anc80 to provide durable cure of phenylketonuria in a mouse model.

Phenylketonuria (PKU) is the most common inborn error of metabolism of the liver, and results from mutations of both alleles of the phenylalanine hydroxylase gene (PAH). As such, it is a suitable target for gene therapy via gene delivery with a recombinant adeno-associated virus (AAV) vector. Here we use the synthetic AAV vector Anc80 via systemic administration to deliver a functional copy of a codon-optimized human PAH gene, with or without an intron spacer, to the Pahenu2 mouse model of PKU. Dose-dependent transduction of the liver and expression of PAH mRNA were present with both vectors, resulting in significant and durable reduction of circulating phenylalanine, reaching near control levels in males. Coat color of treated Pahenu2 mice reflected an increase in pigmentation from brown to the black color of control animals, further indicating functional restoration of phenylalanine metabolism and its byproduct melanin. There were no adverse effects associated with administration of AAV up to 5 × 1012 VG/kg, the highest dose tested. Only minor and/or transient variations in some liver enzymes were observed in some of the AAV-dosed animals which were not associated with pathology findings in the liver. Finally, there was no impact on cell turnover or apoptosis as evaluated by Ki-67 and TUNEL staining, further supporting the safety of this approach. This study demonstrates the therapeutic potential of AAV Anc80 to safely and durably cure PKU in a mouse model, supporting development for clinical consideration.

Imaging of patients with multiple myeloma and associated plasma cell disorders: consensus practice statement by the Medical Scientific Advisory Group to Myeloma Australia.

Imaging modalities for multiple myeloma (MM) have evolved to enable earlier detection of disease. Furthermore, the diagnosis of MM requiring therapy has recently changed to include disease prior to bone destruction, specifically the detection of focal bone lesions. Focal lesions are early, abnormal areas in the bone marrow, which may signal the development of subsequent lytic lesions that typically occur within the next 18-24 months. Cross-sectional imaging modalities are more sensitive for the detection and monitoring of bone and bone marrow disease and are now included in the International Myeloma Working Group current consensus criteria for initial diagnosis and treatment response assessment. The aim of this consensus practice statement is to review the evidence supporting these modalities. A more detailed Position Statement can be found on the Myeloma Australia website.

Pilot study investigating the effect of enteral and parenteral nutrition on the gastrointestinal microbiome post-allogeneic transplantation.

Nutrition support is frequently required post-allogeneic haematopoietic progenitor cell transplantation (HPCT); however, the impact of mode of feeding on the gastrointestinal microbiome has not been explored. This study aimed to determine if there is a difference in the microbiome between patients receiving enteral nutrition (EN) and parenteral nutrition (PN) post-allogeneic HPCT. Twenty-three patients received either early EN or PN when required. Stool samples were collected at 30 days post-transplant and analysed with shotgun metagenomic sequencing. There was no difference in microbial diversity between patients who received predominantly EN (n = 13) vs. PN (n = 10) however patients who received predominantly EN had greater abundance of Faecalibacterium (P < 0·001) and ruminococcus E bromii (P = 0·026). Patients who had minimal oral intake for a longer duration during provision of nutrition support had a different overall microbial profile (P = 0·044), lower microbial diversity (P = 0·004) and lower abundance of faecalibacterium prausnitzii_C (P = 0·030) and Blautia (P = 0·007) compared to patients with greater oral intake. Lower microbial diversity was found in patients who received additional beta lactam antibiotics (P = 0·042) or had a longer length of hospital stay (P = 0·019). Post-HPCT oral intake should be encouraged to maintain microbiota diversity and, if nutrition support is required, EN may promote a more optimal microbiota profile.

Nutrition support during allogeneic stem cell transplantation: evidence versus practice.

PURPOSE: Enteral (EN) or parenteral nutrition (PN) is frequently required during allogeneic haematopoietic progenitor cell transplantation (HPCT), however there is limited consensus on the appropriate mode and timing of nutrition support commencement. This study aimed to investigate current nutrition support practices in Australian allogeneic transplant units and explore barriers and enablers to the use of EN and PN. METHODS: All Australian adult allogeneic HPCT units were eligible to participate. A survey tool was developed, and phone interview with each unit dietitian was completed to explore current nutrition support and perceived barriers and enablers to provision of nutrition care. RESULTS: A total of 12 (100%) units agreed to participate. Six (50%) units reported using PN as standard care and six use EN routinely for one or more conditioning regimens. All units using EN place feeding tubes proactively with tolerance of EN reported at 50-95%. The most frequently reported barriers to the use of EN include perception of poor EN tolerance, medical team preference for PN, gastrointestinal symptoms and thrombocytopenia. Reported barriers to the use of PN include fluid overload, elevated liver enzymes, patient apprehension about PN commencement, medical team uncertainty if PN is required and patients approaching engraftment. CONCLUSION: There is wide variation in the mode and timing of nutrition support provided to patients undergoing allogeneic HPCT. Clinical guidelines should be updated to reflect recent findings on EN use and incorporate strategies to optimise EN tolerance. This will assist in standardising practice and facilitate evidence-based nutrition care.

Evaluation of pharmacokinetic/pharmacodynamic and clinical outcomes with 6-hourly empiric piperacillin-tazobactam dosing in hematological malignancy patients with febrile neutropenia.

BACKGROUND: Piperacillin-tazobactam is commonly used in neutropenic sepsis at standard doses that do not account for inter-individual differences in age, bodyweight and renal function. This study was designed to assess the rate of attainment of pharmacokinetic/pharmacodynamic (PK/PD) targets in patients receiving piperacillin/tazobactam therapy and to evaluate the effect on clinical outcomes. METHODS: Patients undergoing intensive chemotherapy for aggressive hematological malignancies were enrolled and treated with piperacillin/tazobactam 4 g/0.5 g every 6 h as initial antimicrobial therapy for first fever. Plasma drug concentrations were assayed at 50% and 100% of the dosing interval and compared with target MIC breakpoint of 16 mg/L to calculate the primary endpoints of 50% and 100% time above MIC (fT > MIC), respectively. Secondary endpoints included time to clinical cure, length of hospital stay, duration of antibiotics, and clinical treatment success. RESULTS: Fifty-eight percent (14/24) of patients achieved 50% fT > MIC while only 4% (1/24) achieved 100% fT > MIC. Higher creatinine clearance was significantly associated with lower trough drug concentration and appeared to be the dominant reason for the poor PK/PD target attainment. Median time to clinical cure, duration of antibiotic therapy, and hospital length of stay was 3, 13 and 21 days, respectively. There were no statistically significant differences in these outcomes between patients who did and did not achieve 100% fT > MIC. CONCLUSIONS: A significant majority of febrile neutropenic patients fail to achieve PK/PD targets with 6-hourly piperacillin dosing, although the clinical implications of this finding are unclear. Larger studies are needed to assess any impact on morbidity and mortality. This trial is registered on the ANZCTR (ACTRN12618000110280).

Clinical characteristics and imaging features of small bowel adenocarcinomas in Crohn's disease.

PURPOSE: Small bowel adenocarcinoma is uncommon in patients with Crohn's disease but has an extremely poor prognosis. There is a paucity of data on the clinical characteristics and radiologic features of this entity. We sought to update our institutional experience with small bowel adenocarcinoma occurring in the setting of Crohn's disease and to systematically re-examine pre-operative imaging findings. METHODS: Medical records were abstracted to identify all patients with Crohn's disease and small bowel adenocarcinoma who were evaluated at Mayo Clinic, Rochester, Minnesota and Mayo Clinic, Scottsdale, Arizona between 1976 and 2012. Clinical, demographic, and outcomes data were obtained for each patient. Pre-diagnosis radiologic imaging was re-evaluated by two gastrointestinal radiologists. RESULTS: Thirty-four patients (21 males) were identified. Median ages at Crohn's disease and cancer diagnoses were 22.4 and 52.9 years, respectively. Median follow-up after cancer diagnosis was 272.0 days; 22 patients (64.7%) had persistent or recurrent adenocarcinoma at last follow-up. 1- and 2-year mortality rates were 29.6% and 48.0%. Pre-operative imaging studies were available for re-review in 14 cases. Features concerning for malignancy included annular mass, nodularity at the extraluminal margins of the mass, and perforation. Nearly all tumors arose in regions of chronic inflammation and caused luminal narrowing with pre-stenotic dilatation. CONCLUSIONS: Small bowel adenocarcinoma is rare in patients with Crohn's disease but results in significant mortality. CT or MR imaging findings can be suggestive of the pre-operative diagnosis, but it is usually diagnosed at an advanced stage with laparotomy.

Validation of a CT-derived method for osteoporosis screening in IBD patients undergoing contrast-enhanced CT enterography.

OBJECTIVES: Osteoporosis and bone fractures are of particular concern in patients with inflammatory bowel disease (IBD). Biomechanical computed tomography (BCT) is an image-analysis technique that can measure bone strength and dual-energy X-ray absorptiometry (DXA)-equivalent bone mineral density (BMD) from noncontrast CT images. This study seeks to determine whether this advanced technology can be applied to patients with IBD undergoing CT enterography (CTE) with IV contrast. METHODS: Patients with IBD who underwent a CTE and DXA scan between 2007 and 2011 were retrospectively identified. Femoral neck BMD (g/cm(2)) and T-scores were measured and compared between DXA and BCT analysis of the CTE images. Femoral strength (Newtons) was also determined from BCT analysis. RESULTS: DXA- and CTE-generated BMD T-score values were highly correlated (R(2)=0.84, P<0.0001) in this patient cohort (n=136). CTE identified patients with both osteoporosis (sensitivity, 85.7%; 95% confidence interval (CI), 48.7-97.4 and specificity, 98.5%; 95% CI, 94.5-99.6) and osteopenia (sensitivity, 85.1%; 95% CI, 72.3-92.6 and specificity, 85.4%; 95% CI, 76.6-91.3). Of the 16 patients who had "fragile" bone strength by BCT (placing them at the equivalent high risk of fracture as for osteoporosis), 6 had osteoporosis and 10 had osteopenia by DXA. CONCLUSIONS: CTE scans can provide hip BMD, T-scores, and clinical classifications that are comparable to those obtained from DXA; when combined with BCT analysis, CTE can identify a subset of patients with osteopenia who have clinically relevant fragile bone strength. This technique could markedly increase bone health assessments in IBD patients already undergoing CTE to evaluate small bowel disease.

Proactive enteral nutrition for patients undergoing allogeneic stem cell transplantation- implementation and clinical outcomes.

BACKGROUND/ OBJECTIVES: Nutrition support is frequently required post allogeneic haematopoietic progenitor cell transplantation (HPCT) however the tolerance of enteral nutrition (EN) can vary. This mixed methods study aimed to explore staff perceptions, barriers and enablers to the use of EN post HPCT and report the implementation and outcomes of a nutrition protocol. SUBJECT/ METHODS: A survey on barriers and enablers to the use of EN was developed and distributed to medical and nursing staff. Data on nutrition and clinical outcomes was collected for 12 months post implementation of a new nutrition protocol. RESULTS: Thirty staff completed the survey, key barriers identified included uncertain EN tolerance, lack of confidence in nasogastric tube placement and insufficient training and resources. Eighty-four patients commenced EN, 23 changed to PN (27%) and 61 received EN only (73%). In total 36 patients received PN and eight patients oral nutrition support only. There was a difference in type of conditioning (p = 0.025) and nutritional status (p = 0.016) between patients who received PN vs EN only, with a higher proportion of malnourished patients receiving PN (23% vs 5%). Patients who received PN had a longer length of hospital stay (median 22 vs 19 days, p = 0.012) and lower rate of survival to day 100 (81% vs 95%, p = 0.036) than patients who received EN. CONCLUSION: The use of EN may lead to improved clinical outcomes compared to PN therefore should be implemented as first line nutrition support.

Plain Radiography: A Unique Component of Spinal Assessment and Predictive Health.

While some research supports utilizing plain radiography for measuring biomechanical alignment of the spine for prognosis and treatment, there are contrasting viewpoints regarding both the value and utilization of these procedures in conservative care. Evaluation of both conservative and non-conservative approaches to spinal care revealed vast differences in radiographic utilization and interpretation between orthopedic surgeons, primary care physicians, chiropractic physicians, and physical therapists, which may account for the different viewpoints and rationales in the literature. A research summary is provided to explore any unique biomechanical parameters identified with plain radiography of the spine (PROTS) and how these measurements may relate to patient health. Understanding any unique value provided through biomechanical assessment utilizing PROTS may help chiropractic physicians determine the appropriate use of radiographic procedures in clinical practice and how to coordinate efforts with other conservative and non-conservative spinal healthcare professions to improve patient health.

An unappreciated cell survival-independent role for BAFF initiating chronic lymphocytic leukemia.

Background: Chronic Lymphocytic Leukemia (CLL) is characterized by the expansion of CD19+ CD5+ B cells but its origin remains debated. Mutated CLL may originate from post-germinal center B cells and unmutated CLL from CD5+ mature B cell precursors. Irrespective of precursor types, events initiating CLL remain unknown. The cytokines BAFF and APRIL each play a significant role in CLL cell survival and accumulation, but their involvement in disease initiation remains unclear. Methods: We generated novel CLL models lacking BAFF or APRIL. In vivo experiments were conducted to explore the impact of BAFF or APRIL loss on leukemia initiation, progression, and dissemination. Additionally, RNA-seq and quantitative real-time PCR were performed to unveil the transcriptomic signature influenced by BAFF in CLL. The direct role of BAFF in controlling the expression of tumor-promoting genes was further assessed in patient-derived primary CLL cells ex-vivo. Results: Our findings demonstrate a crucial role for BAFF, but not APRIL, in the initiation and dissemination of CLL cells. In the absence of BAFF or its receptor BAFF-R, the TCL1 transgene only increases CLL cell numbers in the peritoneal cavity, without dissemination into the periphery. While BAFF binding to BAFF-R is dispensable for peritoneal CLL cell survival, it is necessary to activate a tumor-promoting gene program, potentially linked to CLL initiation and progression. This direct role of BAFF in controlling the expression of tumor-promoting genes was confirmed in patient-derived primary CLL cells ex-vivo. Conclusions: Our study, involving both mouse and human CLL cells, suggests that BAFF might initiate CLL through mechanisms independent of cell survival. Combining current CLL therapies with BAFF inhibition could offer a dual benefit by reducing peripheral tumor burden and suppressing transformed CLL cell output.

Daratumumab, cyclophosphamide, bortezomib and dexamethasone for non-transplant eligible myeloma (AMaRC 03-16).

In newly diagnosed transplant-ineligible patients with myeloma, daratumumab has improved outcomes when added to the standard of care regimens. In a randomized trial, we tested whether similar improvements would be seen when daratumumab was added to the bortezomib, cyclophosphamide and dexamethasone (VCD) regimen. Non-transplant eligible patients with untreated myeloma were randomized to receive VCD or VCD plus daratumumab (VCDD). 121 patients were randomized, 57 in the VCD arm and 64 in the VCDD arm. Baseline characteristics were balanced between the two arms. The median PFS was 16.8m (95%CI 15.3 - 21.7m) and 25.8m (95%CI 19.9 - 33.5) in the VCD and VCDD arms, respectively (HR 0.67, log-rank test p=0.066). In a pre-planned analysis, the estimated PFS at fixed time-points post-randomization demonstrated significantly improved PFS for the daratumumab containing arm from 18 months onwards. The proportions of patients who were progression free at the following time points were: 18 months, 48% vs 68% (p=0.0002); 24 months, 36% vs 52% (p=0.0001); and 30 months, 27% vs 41% (p<0.0001) in the VCD and VCDD arms, respectively. The best overall response and VGPR rate were significantly better in the daratumumab arm (65% vs 86%, p=0.007 and 28% vs 52%, p=0.009) for the VCD and VCDD arms, respectively. Seventy-two percent of the VCDD patients completed the 9 cycles of induction therapy with no grade 3 or 4 peripheral neuropathy adverse events. This study supports VCDD as an option for the initial treatment of non-transplant eligible patients with myeloma. Australian and New Zealand Clinical Trials Registry (ACTRN12617000202369). https://www.anzctr.org.au/.

Targeted DNA mutagenesis for the cure of chronic viral infections.

Human immunodeficiency virus type 1 (HIV-1), hepatitis B virus (HBV), and herpes simplex virus (HSV) have been incurable to date because effective antiviral therapies target only replicating viruses and do not eradicate latently integrated or nonreplicating episomal viral genomes. Endonucleases that can target and cleave critical regions within latent viral genomes are currently in development. These enzymes are being engineered with high specificity such that off-target binding of cellular DNA will be absent or minimal. Imprecise nonhomologous-end-joining (NHEJ) DNA repair following repeated cleavage at the same critical site may permanently disrupt translation of essential viral proteins. We discuss the benefits and drawbacks of three types of DNA cleavage enzymes (zinc finger endonucleases, transcription activator-like [TAL] effector nucleases [TALENs], and homing endonucleases [also called meganucleases]), the development of delivery vectors for these enzymes, and potential obstacles for successful treatment of chronic viral infections. We then review issues regarding persistence of HIV-1, HBV, and HSV that are relevant to eradication with genome-altering approaches.

Gene therapy for liver diseases - progress and challenges.

Gene therapy is poised to revolutionize modern medicine, with seemingly unlimited potential for treating and curing genetic disorders. For otherwise incurable indications, including most inherited metabolic liver disorders, gene therapy provides a realistic therapeutic option. In this Review, we discuss gene supplementation and gene editing involving the use of recombinant adeno-associated virus (rAAV) vectors for the treatment of inherited liver diseases, including updates on several ongoing clinical trials that are producing promising results. Clinical testing has been essential in highlighting many key translational challenges associated with this transformative therapy. In particular, the interaction of a patient's immune system with the vector raises issues of safety and the duration of treatment efficacy. Furthermore, several serious adverse events after the administration of high doses of rAAVs suggest greater involvement of innate immune responses and pre-existing hepatic conditions than initially anticipated. Finally, permanent modification of the host genome associated with rAAV genome integration and gene editing raises concerns about the risk of oncogenicity that require careful evaluation. We summarize the main progress, challenges and pathways forward for gene therapy for liver diseases.

Relapsed nodular lymphocyte-predominant Hodgkin lymphoma presenting as severe paraneoplastic hepatitis: a case report.

BACKGROUND: Hematological malignancies are an infrequent but important cause of liver dysfunction. There are several mechanisms by which this can occur, including direct malignant infiltration of the hepatic parenchyma and/or vasculature, vanishing bile duct syndrome, and paraneoplastic hepatitis. Paraneoplastic hepatitis is an extremely rare mechanism by which a hematological malignancy can cause liver dysfunction, and we present the first case, to our knowledge, of paraneoplastic hepatitis caused by nodular lymphocyte-predominant Hodgkin lymphoma in the literature. CASE PRESENTATION: A 28-year-old Caucasian male presented with 3 weeks of fatigue, epigastric pain, and jaundice. His medical history was significant for early stage nodular lymphocyte-predominant Hodgkin lymphoma in the cervical region in remission for 5 years after primary treatment with involved-field radiotherapy. Liver biochemistry was normal at the time of treatment for lymphoma and there was no known liver disease before the current presentation. On physical examination, there was scleral icterus and ecchymoses, but no evidence of hepatic encephalopathy, other stigmata of chronic liver disease, or lymphadenopathy. A computed tomography scan of his neck, chest, abdomen, and pelvis showed heterogeneous enhancement of the liver, multiple enlarged upper abdominal lymph nodes, and an enlarged spleen with multiple rounded lesions. Portal and hepatic veins were patent. Initial workup for viral, autoimmune-, toxin-, and medication-related hepatitis was negative. A transjugular liver biopsy was performed with histology showing a predominantly T-cell mediated hepatitis with very extensive multiacinar hepatic necrosis, but no evidence of lymphoma within the liver. Retroperitoneal lymph node biopsy revealed nodular lymphocyte-predominant Hodgkin lymphoma. The patient's symptoms, bilirubin, and transaminases improved significantly after treatment with oral prednisolone and a staged introduction of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy. CONCLUSIONS: Nodular lymphocyte-predominant Hodgkin lymphoma may cause paraneoplastic hepatitis. Physicians should be aware of the possibility of this life-threatening presentation and the importance of early liver biopsy and treatment before acute liver failure occurs. Interestingly, paraneoplastic hepatitis did not occur when nodular lymphocyte-predominant Hodgkin lymphoma was first diagnosed and confined to the cervical region, but was the presenting feature of the recurrence below the diaphragm.

Rescue of infant progressive familial intrahepatic cholestasis type 3 mice by repeated dosing of AAV gene therapy.

Background & Aims: Gene therapy using recombinant adeno-associated virus (rAAV) vector carrying multidrug resistance protein 3 (MDR3) coding sequence (AAV8-MDR3) represents a potential curative treatment for progressive familial intrahepatic cholestasis type 3 (PFIC3), which presents in early childhood. However, patients with the severest form of PFIC3 should receive treatment early after detection to prevent irreversible hepatic fibrosis leading ultimately to liver transplantation or death. This represents a challenge for rAAV-based gene therapy because therapeutic efficacy is expected to wane as rAAV genomes are lost owing to hepatocyte division, and the formation of AAV-specific neutralising antibodies precludes re-administration. Here, we tested a strategy of vector re-administration in infant PFIC3 mice with careful evaluation of its oncogenicity - a particular concern surrounding rAAV treatment. Methods: AAV8-MDR3 was re-administered to infant Abcb4 -/- mice 2 weeks after a first dose co-administered with tolerogenic nanoparticles carrying rapamycin (ImmTOR) given at 2 weeks of age. Eight months later, long-term therapeutic efficacy and safety were assessed with special attention paid to the potential oncogenicity of rAAV treatment. Results: Co-administration with ImmTOR mitigated the formation of rAAV-specific neutralising antibodies and enabled an efficacious second administration of AAV8-MDR3, resulting in stable correction of the disease phenotype, including a restoration of bile phospholipid content and healthy liver function, as well as the prevention of liver fibrosis, hepatosplenomegaly, and gallstones. Furthermore, efficacious repeat rAAV administration prevented the appearance of liver malignancies in an animal model highly prone to developing hepatocellular carcinoma. Conclusions: These outcomes provide strong evidence for rAAV redosing through co-administration with ImmTOR, as it resulted in a long-term therapeutic effect in a paediatric liver metabolic disorder, including the prevention of oncogenesis. Impact and implications: Redosing of gene therapy for inborn hepatobiliary disorders may be essential as effect wanes during hepatocyte division and renewal, particularly in paediatric patients, but the approach may carry long-term risks of liver cancer. Viral vectors carrying a therapeutic gene exerted a durable cure of progressive familial intrahepatic cholestasis type 3 in infant mice and reduced the risk of liver cancer only following a second administration.