Introduction
Pathophysiological basis of therapy
Therapeutic approaches
Bile acid therapeutics
Ursodeoxycholic acid
References | Year | N | Design | Lab inclusion criteria | Results—ALP | Other results |
---|---|---|---|---|---|---|
Beuers et al. [70] | 1992 | 14 | 12 months Treatment group: N = 6 (one of these was excluded at 6 months—> n = 5 in analyses) | ALP > 1.5 × ULN Bilirubin > 15 mg/dL | Reduction in ALP (− 67%) in UDCA group compared with placebo group; ΔALP − 72.6% in UDCA group compared to baseline; all 5 patients in UDCA group compared to 3/7 patients in the placebo group achieved ALP reduction | Reduced GGT (− 53%), bilirubin (− 50%) and ALT (− 36%) compared with placebo group |
Lindor et al. [71] | 1997 | 102 | 2 years (at least 3 months; median follow-up 2.2 years) Double-blind RCT Multicenter Treatment group: N = 51 | ALP > 1.5 × ULN | ΔALP − 40.6% (UDCA group) compared to baseline, compared with ΔALP − 6.1% (placebo group) | ΔAST − 43.3% compared to baseline No significant effect on primary end-points (death, OLT, histology) |
Mitchell et al. [72] | 2001 | 26 | 2-years Double-blind RCT | Stable liver biochemistry for 3 months prior to entry; cholestatic liver enzyme pattern | Reduction in ALP (− 45.4%) compared with baseline | ΔGGT − 62.6% compared with baseline Reduced cholangiographic findings Reduction in histological stage using Modified Histological Activity Index after Ishak in the UDCA group: inflammation ↓ n = 5, unchanged n = 4, ↑ n = 2; stage ↓ one stage n = 3, unchanged n = 6, ↑ (progression) n = 2 |
Harnois et al. [196] | 2001 | 30 | 12 months Pilot open-label study, compared to UDCA low-dose and placebo groups of a previous RCT Treatment group: N = 30 | ALP > 1.5 × ULN | ALP reduction of > − 50% compared to baseline was achieved by 38% at 12 months Reduction in ALP (− 45.2%) | Reduction in AST (− 52.2%) Reduction in bilirubin (− 44.4%) in n = 11 with abnormal bilirubin at baseline Reduction in Mayo risk score was greater in UDCA high-dose group compared with reduction in the placebo and UDCA low-dose groups in a previous study (− 0.542 ± 0.15 vs 0.167 ± 0.09 and − 0.303 ± 0.12, respectively |
Olsson et al. [8] | 2005 | 219 | 5 years RCT Multicenter | No | A non-significant trend towards ALP reduction with ΔALP ca 0.3 µkat at 6 months and stable thereafter in UDCA group compared to no change in placebo group | No effect on death, OLT or CCA |
Lindor et al. [10] | 2009 | 149 | 6 years Treatment group: N = 76 | ALP > 1.5 × ULN | Reduction in median ALP (− 48.5%) compared with baseline in UDCA group at 36 months (however n = 73 at baseline n = 53 at 36 months), − 25% in placebo group | Terminated at 6 years as worse outcome in treatment group for death or OLT |
norUrsodeoxycholic acid
Therapy | References | N | Design | Lab inclusion criteria | Primary endpoint | Result ALP | Other results |
---|---|---|---|---|---|---|---|
Therapy targeting bile acids | |||||||
norUDCA UDCA derivative | Fickert et al. [197] | 161 | RCT Multicenter Phase II 12 weeks | Bilirubin < 3.0 mg/dL | ΔALP at 12 weeks | Significant dose-dependent reductions in ALP; ΔALP (compared to placebo) − 12.3%, − 17.3% and − 26.0% in the 500, 1000 and 1500 mg treatment groups | Favorable safety profile (no increase in pruritus) |
NGM282 FGF-19 analogue | Hirschfield et al. [107] | 62 | RCT Phase II 12 weeks | No | ΔALP at 12 weeks | No significant change in ALP | Reduced BA Improved (reduced) fibrosis markers ELF test and PRO-C3 |
Obeticholic acid (OCA) FXR agonist AESOP trial | Kowdley et al. [100] | 76 | RCT Phase II 24 weeks | ALP ≥ 2.0*ULN Bilirubin < 2.5*ULN | ΔALP at 24 weeks | Significant reduction in ALP in the 5–10 mg treatment arm compared to placebo; ΔALP − 25% from baseline in the 5–10 mg treatment arm compared to ΔALP − 4.8% in placebo group; ΔALP − 14% vs − 25% in patients with and without UDCA at baseline in the 5–10 mg OCA arm | Increased pruritus; pruritus (severe pruritus) reported in 46% (8%), 60% (16%) and 67% (41%) in placebo, 1.5–3 mg and 5–10 mg groups; n = 15 drop-outs prior to 24 week assessment |
LUM001/maralixibat ASBT inhibitor CAMEO trial | Completed; Results at clinicaltrials.gov | 27 | Open label pilot 14 weeks | ALT and AST ≤ 5*ULN | Δbile acid levels at 14 weeks | No reduction in ALP | ΔBA − 14.8 (− 38%) |
Therapy targeting PPAR | |||||||
Bezafibrate 400 mg/day | Mizuno et al. [121] | 7 | Open-label pilot 6 months | ALP > 1.5 × ULN | ΔALP at 6 months | ALP reduction with about 40% in 3/7 patients at 6 months | |
Bezafibrate 400 mg/day | Mizuno et al. [122] | 11 | Open-label pilot 12 weeks | ΔALP at 12 weeks | ALP reduction at 12 weeks, ALP increase subsequent to treatment cessation | ||
Bezafibrate 400 mg/day or fenofibrate 200 mg/day | Lemoinne et al. [123] | 20 | Retrospective study | ALP > 1.5 × ULN on UDCA | ΔALP | Reduced ALP after at least 6 months; 40% reached ALP < 1.5 × ULN | Reduced ALT and pruritus |
Fenofibrate | Dejman et al. [124] | 8 | Open label pilot 6 months | ALP > 1.5 × ULN | ΔALP at 6 months | Significant ALP reduction: ΔALP − 43% | Reduced ALT No significant effect on Mayo risk score |
Therapy targeting gut microbiota | |||||||
Vancomycin vs metronidazole | Tabibian et al. [137] | 28 | RCT Phase II-III Multicenter 12 weeks | ALP > 1.5*ULN | ΔALP at 12 weeks | Non-dose dependent ALP reduction in all 4 treatment arms (low vs high dose vancomycin or metronidazole) | |
Vancomycin | Rahimpour et al. [138] | 29 | RCT 12 weeks | No | ΔMayo risk score | ALP reduction at 12 weeks; ΔALP − 18.2% | Reduced Mayo risk score |
Metronidazole | Farkkila et al. 2004 [139] | 80 | RCT Phase III 36 months | No / not specified (possibly ALP or ALT > ULN) | ΔALP or other liver enzymes, Mayo risk score, symptoms or histology at 36 months | ALP reduction at 36 months; ΔALP − 52.4% vs − 37.7% in metronidazole + UDCA group vs UDCA + placebo group | Reduced Mayo risk score; higher proportion of patients showed histologic improvement of stage or grade |
Minocycline | Silveira et al. [143] | 16 | Open-label pilot 12 months | ALP > 1.5*ULN | ΔALP at 12 months | ALP reduction at 12 months; ΔALP − 20% | Reduced Mayo risk score |
Rifaximin | Tabibian et al. [140] | 16 | Open-label pilot 3 months | ALP > 1.5*ULN | 50% ALP reduction at 3 months | No significant ALP reduction | No significant reduction in bilirubin, GGT, Mayo risk score |
Fecal transplantation | Allegretti et al. [41] | 10 | Open-label pilot 24 weeks | ALP > 1.5*ULN | ≥ 50% ALP reduction at week 24 | 30% (3/10) experienced a ≥ 50% decrease in ALP | |
Immune modulating therapy | |||||||
All-trans retinoic acid | Assis et al. [115] | 15 | Open-label pilot 12 weeks | ALP > 1.5 × ULN on UDCA | ΔALP − 30% at 12 weeks | Non-significant ALP reduction; 3/15 achieved ≥ 30% ALP reduction | Reduced ALT and C4; ALT returned to pre-treatment values after washout period |
Infliximab | Hommes et al. [167] | 10 | RCT 52 weeks | ALP > 2*ULN | ≥ 50% ALP reduction at week 18 | Failed to demonstrate effect in the n = 6 treatment group | No change in histologic stage or symptom scores |
Other or undefined targets | |||||||
Cenicriviroc Anti-inflammatory effects (CCR2/CCR5 antagonist) PERSEUS trial | Completed, not published; results at clinicaltrials.gov | 20 | Open label Phase II 24 weeks | ALP > 1.5*ULN Bilirubin ≤ 2.0 mg/dL | ALP (%Δ) | 50% (n = 10) of patients achieved ALP reduction to < 1.5*ULN at 24 weeks. Mean ALP reduction − 4.5% at 24 weeks. No patients achieved ALP normalization or 50% ALP reduction | |
Curcumin Anti-inflammatory effects, upregulation of PPAR-γ? | Completed, not published | 15 | Phase I–II Open-label | ALP > 1.5*ULN | ALP 40% reduction or reduction to < 1.5*ULN | Results submitted to clinicaltrials.gov, but not posted |
Therapy | Pathophysiologic target | Trial phase | Design | Lab inclusion criteria | Primary endpoint | Secondary endpoint |
---|---|---|---|---|---|---|
Bile acid based therapy | ||||||
NorUDCA | UDCA derivative Unknown receptor | III | Double-blind RCT Multicenter | No (?) | ALP partial normalization | Histology |
Cilofexor | FXR agonist | III | Double-blind RCT | ALT ≤ 8*ULN Bilirubin ≤ 2.0 mg/dL INR ≤ 1.4 Platelets ≥ 150,000 | Histology | ΔALP Δother liver biochemistries ΔLSM (TE) + + |
Therapy targeting PPAR | ||||||
Seladelpar | Selective PPAR-δ agonist | II | Double-blind RCT | ALP ≥ 1.5*ULN and < 8*ULN Bilirubin ≤ 2*ULN ALT and AST ≤ 5*ULN Platelets ≥ 140,000 | ΔALP at 24 w | LTX ΔMELD Hepatic decompensating events HCC |
Bezafibrate | PPAR-α agonist | III | Double-blind RCT | No | Proportion of patients reaching 50% reduction in itch intensity at 3 weeks | Δliver biochemistries Δautotaxin activity Δcholesterol, CK, creatinine |
Therapy targeting gut microbiota | ||||||
Vancomycin | Antibiotic | III | Double-blind RCT Multicenter | ALP ≥ 1.5*ULN | ALP normalization at 6, 12, 18, 21, 24 months | ΔTE at 18 months |
Immune modulating therapy | ||||||
Simvastatin | Immune modulating, receptor? | III | Double-blind RCT Multicenter | No | Overall survival; Listing for liver transplantation; Time to first varices bleeding or CCA, GBC, HCC | ΔALP Δbilirubin ΔMELD or ΔChild–Pugh MRCP progression ΔLSM (TE) or Δserum fibrosis markers Progression of symptoms, biliary dysplasia, colon cancer or dysplasia |
Timolumab BTT1023 BUTEO trial | Anti-VAP-1 antibody | II | Open label | ALP > 1.5*ULN Stable ALP i.e. < 25% variation between screening visits 1 and 2 | ALP 25% reduction by day 99 | |
All-trans retinoic acid | FXR/RXR complex activation | II | Open label | ALP ≥ 1.5*ULN | ΔALP at 24 w | ALP > 1.5*ULN ΔALT Δbile acids ΔELF test ΔLSM (TE) |
Sulfasalazine | Immune modulating | II | Double-blind RCT Multicenter | ALP ≥ 1.67*ULN Bilirubin ≤ 3 mg/dL INR ≤ 1.4 Platelets ≥ 100,000 MELD ≤ 10 | ALP ≥ 1.5 at 22 w | Δother liver biochemistries ΔMayo risk score Symptoms |
Vidofludimus calcium | Blocks IL-17 production | II | Open label | ALP > 1.5*ULN Indirect bilirubin < 1.2 *ULN | ΔALP at 3 and 6 months | Δother liver biochemistries IL-17 and IFNγ levels at 3 and 6 months |
Steroidal FXR agonists
Non-steroidal FXR agonists
Aldafermin (NGM282)
ASBT inhibitors
All-trans retinoic acid
Fibrates and PPAR activation
Gut microbiota targeting therapy
Antibiotic therapy
Fecal transplantation
Probiotics and bacteriophage applications
Immune modulating therapy
Glucocorticoids: immunosuppression in PSC with features of autoimmune hepatitis
Azathioprine, ciclosporin, tacrolimus, methotrexate, and mycophenolate
Biologics in the treatment of PSC
Anti-inflammatory and anti-fibrotic therapies
Study design and biomarkers
Alkaline phosphatase
Other surrogate endpoints
Biomarker | Pathophysiologic target | PRO | CON |
---|---|---|---|
Non-invasive: serum based tests and clinical scores | |||
ALP | Cholestasis Inflammation | Fluctuates naturally during the course of PSC, thus single measurements in individuals are unreliable Diverging definitions of defined risk groups or treatment effect across studies (various cutoff values proposed; or 40% reduction in ALP; or normalization); attempts at cross-validation of suggested definitions have failed | |
Amsterdam-Oxford model | Clinical score; PSC subtype, age at PSC diagnosis, albumin, platelets, AST, ALP, bilirubin | Dynamic features and responsiveness to various therapies have not been tested Some components are not modifiable by therapy | |
Autotaxin | Variation over time in individuals not tested | ||
Bilirubin | Cholestasis | Consistent and strong association with clinical outcome in multiple studies. Directly reflects cholestasis, thus biologically meaningful | Intercurrent increases may be due to temporary and treatable bile duct obstruction by gallstones or sludge, bacterial cholangitis, or strictures available to endoscopic therapy. Increasing bilirubin due to liver failure is a late event in PSC and not useful as a surrogate marker in early disease |
CD14 | Gut barrier function: bacterial translocation | Associated with transplant-free survival in a monocenter study, independent of Mayo score [33] | Independent validation is lacking Variation over time in individuals not tested |
ELF test | Fibrosis A direct test of fibrogenesis based on a panel of fibrosis markers (HA, PIIINP, TIMP-1) | Strong association with clinical outcome (LTX or death) independently of the Mayo risk score; initially shown in two independent panels at a single center, then independently validated in a large, international multicentre study [189, 190] Showed change at 12 weeks of treatment in a phase II study on NGM282, indicating dynamic potential [107] ELF test directly reflects fibrogenesis, which is important in the pathogenesis of PSC and a therapeutic target | Variation over time in individuals not tested. Usefulness in early disease not tested |
IL-8 | Inflammation | Associated with clinical outcome in PSC as a serum marker (and in bile) [194]. May reflect biliary inflammation as a clinically meaningful biological pathway | Outperformed by fibrosis markers regarding prediction of transplant-free survival |
Mayo risk score | Clinical score; age, bilirubin, AST, INR, variceal bleeding status | Strong association with clinical outcome; the most commonly used clinical risk score in PSC | Not validated at the individual level. Did not predict adverse events in a previous high-dose UDCA trial INR and variceal bleeding and partly bilirubin reflect changes seen in advanced disease Some components are not modifiable by therapy |
PREsTo | Clinical score; age, years since PSC diagnosis, bilirubin, albumin, ALP x ULN, platelets, AST, hemoglobin, sodium | Associated with clinical outcome defined as hepatic decompensation. Derived using machine-learning techniques in a large (n = 509) multicenter North American panel and validated in an international multicenter cohort (n = 278) [201] | Validation in an independent study is lacking Some components are not modifiable by therapy |
PRO-C3 | Fibrosis A specific marker of collagen III formation | Associated with clinical outcome (LTX or death) in a single center study [193] Showed change at 12 weeks of treatment in a phase II study on NGM282, indicating dynamic potential [107] PRO-C3 directly reflects collagen III formation, which is an important part of fibrogenesis and hence the pathogenesis of PSC, and a therapeutic target | Usefulness in early disease not tested |
PRO-C5 | Fibrosis A specific marker of collagen V formation | Associated with clinical outcome (LTX or death) in a single center study [193] | Usefulness in early disease not tested |
VAP-1 | Autoimmunity Leukocyte recruitment to sites of inflammation | Vap-1 predicted clinical outcome in two independent PSC patient panels from two different centers in one study [177] | No independent validation study No prospective data |
Non-invasive: imaging | |||
Transient elastography (TE) | Fibrosis Liver stiffness as a proxy for fibrosis | Impact of severe cholestasis/cholangitis uncertain Not applicable in ascites or (severe) obesity | |
MR elastography (MRE) | Fibrosis Liver stiffness as a proxy for fibrosis | Associated with clinical outcome (hepatic decompensation) in a large (n = 266), single center retrospective study [202] | Not widely available Costly. Time-consuming |
Annali score (MRCP) | MRC findings of intrahepatic bile duct dilatation, dysmorphy (lobar atrophy, lobular surface changes, or an abnormal caudate to right lobe volume ratio) and portal hypertension | Major weight on late changes related to cirrhosis Dynamic changes are likely to be slow | |
Invasive | |||
Histological stage | Fibrosis Grading systems may include various pathophysiologic processes | Strong association with clinical outcome (LTX-free survival, time to LTX) for stage assessed by Ishak, Nakanuma, and Ludwig staging systems was demonstrated in a single-center study and validated in an independent international multicentre study. Nakanuma staging appeared to have the best prognostic value [205, 206] Association of Ludwig stage with clinical outcome has been demonstrated in several studies One study estimated (using a Markov model) that change in stage at 2 and 5 years would appear in 66% and 96% of PSC patients with Ludwig’s stage II at baseline, indicating that changes in histology can be seen within the scope of a therapeutic trial [207] | Invasive, risk of adverse events Staging discord between multiple biopsies unless care is taken to biopsy same localization (using ultrasound) No consensus on a single system for histological grading and staging of PSC No data to support the use of change in histological grade as a surrogate marker The most prominent pathology in PSC relates to the larger bile ducts, which are not accessed by standard liver biopsy |
Biliary calprotectin | Biliary inflammation | Associated with transplant-free survival in two studies by independent groups [194, 208]. Biologically meaningful: calprotectin is expressed by neutrophils, activated monocytes and macrophages and acts as a chemotactic molecule, reflecting biliary duct inflammation as a parallel to the use of fecal calprotectin in inflammatory bowel disease | Requires invasive sampling by ERCP, with risk of adverse events |